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Sökning: WFRF:(Henkel C)

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1.
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2.
  • Correa, D. F., et al. (författare)
  • Geographic patterns of tree dispersal modes in Amazonia and their ecological correlates
  • 2023
  • Ingår i: Global Ecology and Biogeography. - : Wiley. - 1466-822X .- 1466-8238. ; 32:1, s. 49-69
  • Tidskriftsartikel (refereegranskat)abstract
    • Aim To investigate the geographic patterns and ecological correlates in the geographic distribution of the most common tree dispersal modes in Amazonia (endozoochory, synzoochory, anemochory and hydrochory). We examined if the proportional abundance of these dispersal modes could be explained by the availability of dispersal agents (disperser-availability hypothesis) and/or the availability of resources for constructing zoochorous fruits (resource-availability hypothesis). Time period Tree-inventory plots established between 1934 and 2019. Major taxa studied Trees with a diameter at breast height (DBH) >= 9.55 cm. Location Amazonia, here defined as the lowland rain forests of the Amazon River basin and the Guiana Shield. Methods We assigned dispersal modes to a total of 5433 species and morphospecies within 1877 tree-inventory plots across terra-firme, seasonally flooded, and permanently flooded forests. We investigated geographic patterns in the proportional abundance of dispersal modes. We performed an abundance-weighted mean pairwise distance (MPD) test and fit generalized linear models (GLMs) to explain the geographic distribution of dispersal modes. Results Anemochory was significantly, positively associated with mean annual wind speed, and hydrochory was significantly higher in flooded forests. Dispersal modes did not consistently show significant associations with the availability of resources for constructing zoochorous fruits. A lower dissimilarity in dispersal modes, resulting from a higher dominance of endozoochory, occurred in terra-firme forests (excluding podzols) compared to flooded forests. Main conclusions The disperser-availability hypothesis was well supported for abiotic dispersal modes (anemochory and hydrochory). The availability of resources for constructing zoochorous fruits seems an unlikely explanation for the distribution of dispersal modes in Amazonia. The association between frugivores and the proportional abundance of zoochory requires further research, as tree recruitment not only depends on dispersal vectors but also on conditions that favour or limit seedling recruitment across forest types.
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3.
  • Tierney, W., et al. (författare)
  • A creative destruction approach to replication : Implicit work and sex morality across cultures
  • 2021
  • Ingår i: Journal of Experimental Social Psychology. - : Elsevier BV. - 0022-1031 .- 1096-0465. ; 93
  • Tidskriftsartikel (refereegranskat)abstract
    • How can we maximize what is learned from a replication study? In the creative destruction approach to replication, the original hypothesis is compared not only to the null hypothesis, but also to predictions derived from multiple alternative theoretical accounts of the phenomenon. To this end, new populations and measures are included in the design in addition to the original ones, to help determine which theory best accounts for the results across multiple key outcomes and contexts. The present pre-registered empirical project compared the Implicit Puritanism account of intuitive work and sex morality to theories positing regional, religious, and social class differences; explicit rather than implicit cultural differences in values; self-expression vs. survival values as a key cultural fault line; the general moralization of work; and false positive effects. Contradicting Implicit Puritanism's core theoretical claim of a distinct American work morality, a number of targeted findings replicated across multiple comparison cultures, whereas several failed to replicate in all samples and were identified as likely false positives. No support emerged for theories predicting regional variability and specific individual-differences moderators (religious affiliation, religiosity, and education level). Overall, the results provide evidence that work is intuitively moralized across cultures.
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4.
  • Delios, A., et al. (författare)
  • Examining the generalizability of research findings from archival data
  • 2022
  • Ingår i: Proceedings of the National Academy of Sciences of the United States of America. - : Proceedings of the National Academy of Sciences. - 0027-8424 .- 1091-6490. ; 119:30
  • Tidskriftsartikel (refereegranskat)abstract
    • This initiative examined systematically the extent to which a large set of archival research findings generalizes across contexts. We repeated the key analyses for 29 original strategic management effects in the same context (direct reproduction) as well as in 52 novel time periods and geographies; 45% of the reproductions returned results matching the original reports together with 55% of tests in different spans of years and 40% of tests in novel geographies. Some original findings were associated with multiple new tests. Reproducibility was the best predictor of generalizability-for the findings that proved directly reproducible, 84% emerged in other available time periods and 57% emerged in other geographies. Overall, only limited empirical evidence emerged for context sensitivity. In a forecasting survey, independent scientists were able to anticipate which effects would find support in tests in new samples. 
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5.
  • Kueppers, Michael, et al. (författare)
  • Triple F-a comet nucleus sample return mission
  • 2009
  • Ingår i: Experimental astronomy. - : Springer Science and Business Media LLC. - 0922-6435 .- 1572-9508. ; 23:3, s. 809-847
  • Tidskriftsartikel (refereegranskat)abstract
    • The Triple F (Fresh From the Fridge) mission, a Comet Nucleus Sample Return, has been proposed to ESA's Cosmic Vision program. A sample return from a comet enables us to reach the ultimate goal of cometary research. Since comets are the least processed bodies in the solar system, the proposal goes far beyond cometary science topics (like the explanation of cometary activity) and delivers invaluable information about the formation of the solar system and the interstellar molecular cloud from which it formed. The proposed mission would extract three sample cores of the upper 50 cm from three locations on a cometary nucleus and return them cooled to Earth for analysis in the laboratory. The simple mission concept with a touch-and-go sampling by a single spacecraft was proposed as an M-class mission in collaboration with the Russian space agency ROSCOSMOS.
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6.
  • Tedersoo, L., et al. (författare)
  • The Global Soil Mycobiome consortium dataset for boosting fungal diversity research
  • 2021
  • Ingår i: Fungal Diversity. - : Springer Science and Business Media LLC. - 1560-2745 .- 1878-9129. ; 111, s. 573-588
  • Tidskriftsartikel (refereegranskat)abstract
    • Fungi are highly important biotic components of terrestrial ecosystems, but we still have a very limited understanding about their diversity and distribution. This data article releases a global soil fungal dataset of the Global Soil Mycobiome consortium (GSMc) to boost further research in fungal diversity, biogeography and macroecology. The dataset comprises 722,682 fungal operational taxonomic units (OTUs) derived from PacBio sequencing of full-length ITS and 18S-V9 variable regions from 3200 plots in 108 countries on all continents. The plots are supplied with geographical and edaphic metadata. The OTUs are taxonomically and functionally assigned to guilds and other functional groups. The entire dataset has been corrected by excluding chimeras, index-switch artefacts and potential contamination. The dataset is more inclusive in terms of geographical breadth and phylogenetic diversity of fungi than previously published data. The GSMc dataset is available over the PlutoF repository.
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7.
  • Harwit, M., et al. (författare)
  • Polarisation observations of VY Canis Majoris H2O 5(32)-4(41) 620.701 GHz maser emission with HIFI
  • 2010
  • Ingår i: Astronomy and Astrophysics. - : EDP Sciences. - 0004-6361 .- 1432-0746. ; 521, s. L51-
  • Tidskriftsartikel (refereegranskat)abstract
    • Context. Water vapour maser emission from evolved oxygen-rich stars remains poorly understood. Additional observations, including polarisation studies and simultaneous observation of different maser transitions may ultimately lead to greater insight. Aims. We have aimed to elucidate the nature and structure of the VY CMa water vapour masers in part by observationally testing a theoretical prediction of the relative strengths of the 620.701 GHz and the 22.235 GHz maser components of ortho H2O. Methods. In its high-resolution mode (HRS) the Herschel Heterodyne Instrument for the Far Infrared (HIFI) offers a frequency resolution of 0.125 MHz, corresponding to a line-of-sight velocity of 0.06 km s(-1), which we employed to obtain the strength and linear polarisation of maser spikes in the spectrum of VY CMa at 620.701 GHz. Simultaneous ground based observations of the 22.235 GHz maser with the Max-Planck-Institut fur Radioastronomie 100-m telescope at Effelsberg, provided a ratio of 620.701 GHz to 22.235 GHz emission. Results. We report the first astronomical detection to date of H2O maser emission at 620.701 GHz. In VY CMa both the 620.701 and the 22.235 GHz polarisation are weak. At 620.701 GHz the maser peaks are superposed on what appears to be a broad emission component, jointly ejected from the star. We observed the 620.701 GHz emission at two epochs 21 days apart, both to measure the potential direction of linearly polarised maser components and to obtain a measure of the longevity of these components. Although we do not detect significant polarisation levels in the core of the line, they rise up to approximately 6% in its wings.
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8.
  • Braine, J., et al. (författare)
  • Cool gas and dust in M33: Results from the HERschel M33 Extended Survey (HERM33ES)
  • 2010
  • Ingår i: Astronomy and Astrophysics. - : EDP Sciences. - 0004-6361 .- 1432-0746. ; 518:Article Number: L69
  • Tidskriftsartikel (refereegranskat)abstract
    • We present an analysis of the first space-based far-IR-submm observations of M33, which measure the emission from the cool dust and resolve the giant molecular cloud complexes. With roughly half-solar abundances, M33 is a first step towards young low-metallicity galaxies where the submm may be able to provide an alternative to CO mapping to measure their H-2 content. In this Letter, we measure the dust emission cross-section sigma using SPIRE and recent CO and HI observations; a variation in s is present from a near-solar neighborhood cross-section to about half-solar with the maximum being south of the nucleus. Calculating the total H column density from the measured dust temperature and cross-section, and then subtracting the HI column, yields a morphology similar to that observed in CO. The H-2/HI mass ratio decreases from about unity to well below 10% and is about 15% averaged over the optical disk. The single most important observation to reduce the potentially large systematic errors is to complete the CO mapping of M33.
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9.
  • Gonzalez-Alfonso, E., et al. (författare)
  • Herschel observations of water vapour in Markarian 231
  • 2010
  • Ingår i: Astronomy and Astrophysics. - : EDP Sciences. - 0004-6361 .- 1432-0746. ; 518:Article Number: L43
  • Tidskriftsartikel (refereegranskat)abstract
    • The Ultra luminous infrared galaxy (ULIRG) Mrk 231 reveals up to seven rotational lines of water (H2O) in emission, including a very high-lying (Eupper = 640 K) line detected at a 4 sigma level, within the Herschel/SPIRE wavelength range (190
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10.
  • Harwit, M., et al. (författare)
  • Polarisation observations of VY Canis Majoris H2O 532-441 620.701 GHz maser emission with HIFI
  • 2010
  • Ingår i: Astronomy and Astrophysics. - : EDP Sciences. - 0004-6361 .- 1432-0746. ; 521:1, s. Article Number: L51-
  • Tidskriftsartikel (refereegranskat)abstract
    • Context. Water vapour maser emission from evolved oxygen-rich stars remains poorly understood. Additional observations, including polarisation studies and simultaneous observation of different maser transitions may ultimately lead to greater insight. Aims. We have aimed to elucidate the nature and structure of the VY CMa water vapour masers in part by observationally testing a theoretical prediction of the relative strengths of the 620.701 GHz and the 22.235 GHz maser components of ortho H2O. Methods. In its high-resolution mode (HRS) the Herschel Heterodyne Instrument for the Far Infrared (HIFI) offers a frequency resolution of 0.125 MHz, corresponding to a line-of-sight velocity of 0.06 km s(-1), which we employed to obtain the strength and linear polarisation of maser spikes in the spectrum of VY CMa at 620.701 GHz. Simultaneous ground based observations of the 22.235 GHz maser with the Max-Planck-Institut fur Radioastronomie 100-m telescope at Effelsberg, provided a ratio of 620.701 GHz to 22.235 GHz emission. Results. We report the first astronomical detection to date of H2O maser emission at 620.701 GHz. In VY CMa both the 620.701 and the 22.235 GHz polarisation are weak. At 620.701 GHz the maser peaks are superposed on what appears to be a broad emission component, jointly ejected from the star. We observed the 620.701 GHz emission at two epochs 21 days apart, both to measure the potential direction of linearly polarised maser components and to obtain a measure of the longevity of these components. Although we do not detect significant polarisation levels in the core of the line, they rise up to approximately 6% in its wings.
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11.
  • Householder, John Ethan, et al. (författare)
  • One sixth of Amazonian tree diversity is dependent on river floodplains
  • 2024
  • Ingår i: NATURE ECOLOGY & EVOLUTION. - 2397-334X. ; 8, s. 901-911
  • Tidskriftsartikel (refereegranskat)abstract
    • Amazonia's floodplain system is the largest and most biodiverse on Earth. Although forests are crucial to the ecological integrity of floodplains, our understanding of their species composition and how this may differ from surrounding forest types is still far too limited, particularly as changing inundation regimes begin to reshape floodplain tree communities and the critical ecosystem functions they underpin. Here we address this gap by taking a spatially explicit look at Amazonia-wide patterns of tree-species turnover and ecological specialization of the region's floodplain forests. We show that the majority of Amazonian tree species can inhabit floodplains, and about a sixth of Amazonian tree diversity is ecologically specialized on floodplains. The degree of specialization in floodplain communities is driven by regional flood patterns, with the most compositionally differentiated floodplain forests located centrally within the fluvial network and contingent on the most extraordinary flood magnitudes regionally. Our results provide a spatially explicit view of ecological specialization of floodplain forest communities and expose the need for whole-basin hydrological integrity to protect the Amazon's tree diversity and its function.
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12.
  • Kramer, C., et al. (författare)
  • PACS and SPIRE photometer maps of M33: First results of the HERschel M33 Extended Survey (HERM33ES)
  • 2010
  • Ingår i: Astronomy and Astrophysics. - : EDP Sciences. - 0004-6361 .- 1432-0746. ; 518:Article Number: L67
  • Tidskriftsartikel (refereegranskat)abstract
    • Context. Within the framework of the HERM33ES key program, we are studying the star forming interstellar medium in the nearby, metal-poor spiral galaxy M33, exploiting the high resolution and sensitivity of Herschel. Aims. We use PACS and SPIRE maps at 100, 160, 250, 350, and 500 mu m wavelength, to study the variation of the spectral energy distributions (SEDs) with galacto-centric distance. Methods. Detailed SED modeling is performed using azimuthally averaged fluxes in elliptical rings of 2 kpc width, out to 8 kpc galacto-centric distance. Simple isothermal and two-component grey body models, with fixed dust emissivity index, are fitted to the SEDs between 24 mu m and 500 mu m using also MIPS/Spitzer data, to derive first estimates of the dust physical conditions. Results. The far-infrared and submillimeter maps reveal the branched, knotted spiral structure of M33. An underlying diffuse disk is seen in all SPIRE maps (250-500 mu m). Two component fits to the SEDs agree better than isothermal models with the observed, total and radially averaged flux densities. The two component model, with beta fixed at 1.5, best fits the global and the radial SEDs. The cold dust component clearly dominates; the relative mass of the warm component is less than 0.3% for all the fits. The temperature of the warm component is not well constrained and is found to be about 60 K +/- 10 K. The temperature of the cold component drops significantly from similar to 24 K in the inner 2 kpc radius to 13 K beyond 6 kpc radial distance, for the best fitting model. The gas-to-dust ratio for beta = 1.5, averaged over the galaxy, is higher than the solar value by a factor of 1.5 and is roughly in agreement with the subsolar metallicity of M33.
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13.
  • Luize, Bruno Garcia, et al. (författare)
  • Geography and ecology shape the phylogenetic composition of Amazonian tree communities
  • 2024
  • Ingår i: JOURNAL OF BIOGEOGRAPHY. - 0305-0270 .- 1365-2699. ; 51:7, s. 1163-1184
  • Tidskriftsartikel (refereegranskat)abstract
    • Aim: Amazonia hosts more tree species from numerous evolutionary lineages, both young and ancient, than any other biogeographic region. Previous studies have shown that tree lineages colonized multiple edaphic environments and dispersed widely across Amazonia, leading to a hypothesis, which we test, that lineages should not be strongly associated with either geographic regions or edaphic forest types. Location: Amazonia. Taxon: Angiosperms (Magnoliids; Monocots; Eudicots). Methods: Data for the abundance of 5082 tree species in 1989 plots were combined with a mega-phylogeny. We applied evolutionary ordination to assess how phylogenetic composition varies across Amazonia. We used variation partitioning and Moran's eigenvector maps (MEM) to test and quantify the separate and joint contributions of spatial and environmental variables to explain the phylogenetic composition of plots. We tested the indicator value of lineages for geographic regions and edaphic forest types and mapped associations onto the phylogeny. Results: In the terra firme and v & aacute;rzea forest types, the phylogenetic composition varies by geographic region, but the igap & oacute; and white-sand forest types retain a unique evolutionary signature regardless of region. Overall, we find that soil chemistry, climate and topography explain 24% of the variation in phylogenetic composition, with 79% of that variation being spatially structured (R-2 = 19% overall for combined spatial/environmental effects). The phylogenetic composition also shows substantial spatial patterns not related to the environmental variables we quantified (R-2 = 28%). A greater number of lineages were significant indicators of geographic regions than forest types. Main Conclusion: Numerous tree lineages, including some ancient ones (>66 Ma), show strong associations with geographic regions and edaphic forest types of Amazonia. This shows that specialization in specific edaphic environments has played a long-standing role in the evolutionary assembly of Amazonian forests. Furthermore, many lineages, even those that have dispersed across Amazonia, dominate within a specific region, likely because of phylogenetically conserved niches for environmental conditions that are prevalent within regions.
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14.
  • Petkova, Maya, 1990, et al. (författare)
  • Kinematics of Galactic Centre clouds shaped by shear-seeded solenoidal turbulence
  • 2023
  • Ingår i: Monthly Notices of the Royal Astronomical Society. - 0035-8711 .- 1365-2966. ; 525:1, s. 962-968
  • Tidskriftsartikel (refereegranskat)abstract
    • The Central Molecular Zone (CMZ; the central ∼500 pc of the Galaxy) is a kinematically unusual environment relative to the Galactic disc, with high-velocity dispersions and a steep size-linewidth relation of the molecular clouds. In addition, the CMZ region has a significantly lower star formation rate (SFR) than expected by its large amount of dense gas. An important factor in explaining the low SFR is the turbulent state of the star-forming gas, which seems to be dominated by rotational modes. However, the turbulence driving mechanism remains unclear. In this work, we investigate how the Galactic gravitational potential affects the turbulence in CMZ clouds. We focus on the CMZ cloud G0.253+0.016 ('the Brick'), which is very quiescent and unlikely to be kinematically dominated by stellar feedback. We demonstrate that several kinematic properties of the Brick arise naturally in a cloud-scale hydrodynamics simulation, that takes into account the Galactic gravitational potential. These properties include the line-of-sight velocity distribution, the steepened size-linewidth relation, and the predominantly solenoidal nature of the turbulence. Within the simulation, these properties result from the Galactic shear in combination with the cloud's gravitational collapse. This is a strong indication that the Galactic gravitational potential plays a crucial role in shaping the CMZ gas kinematics, and is a major contributor to suppressing the SFR, by inducing predominantly solenoidal turbulent modes.
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15.
  • ter Steege, Hans, et al. (författare)
  • Mapping density, diversity and species-richness of the Amazon tree flora
  • 2023
  • Ingår i: COMMUNICATIONS BIOLOGY. - 2399-3642. ; 6:1
  • Tidskriftsartikel (refereegranskat)abstract
    • Using 2.046 botanically-inventoried tree plots across the largest tropical forest on Earth, we mapped tree species-diversity and tree species-richness at 0.1-degree resolution, and investigated drivers for diversity and richness. Using only location, stratified by forest type, as predictor, our spatial model, to the best of our knowledge, provides the most accurate map of tree diversity in Amazonia to date, explaining approximately 70% of the tree diversity and species-richness. Large soil-forest combinations determine a significant percentage of the variation in tree species-richness and tree alpha-diversity in Amazonian forest-plots. We suggest that the size and fragmentation of these systems drive their large-scale diversity patterns and hence local diversity. A model not using location but cumulative water deficit, tree density, and temperature seasonality explains 47% of the tree species-richness in the terra-firme forest in Amazonia. Over large areas across Amazonia, residuals of this relationship are small and poorly spatially structured, suggesting that much of the residual variation may be local. The Guyana Shield area has consistently negative residuals, showing that this area has lower tree species-richness than expected by our models. We provide extensive plot meta-data, including tree density, tree alpha-diversity and tree species-richness results and gridded maps at 0.1-degree resolution. A study mapping the tree species richness in Amazonian forests shows that soil type exerts a strong effect on species richness, probably caused by the areas of these forest types. Cumulative water deficit, tree density and temperature seasonality affect species richness at a regional scale.
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16.
  • van der Werf, P.P., et al. (författare)
  • Black hole accretion and star formation as drivers of gas excitation and chemistry in Markarian 231
  • 2010
  • Ingår i: Astronomy and Astrophysics. - : EDP Sciences. - 0004-6361 .- 1432-0746. ; 518:Article Number: L42
  • Tidskriftsartikel (refereegranskat)abstract
    • We present a full high resolution SPIRE FTS spectrum of the nearby ultraluminous infrared galaxy Mrk 231. In total 25 lines are detected, including CO J = 5-4 through J = 13-12, 7 rotational lines of H2O, 3 of OH+ and one line each of H2O+, CH+, and HF. We find that the excitation of the CO rotational levels up to J = 8 can be accounted for by UV radiation from star formation. However, the approximately flat luminosity distribution of the CO lines over the rotational ladder above J = 8 requires the presence of a separate source of excitation for the highest CO lines. We explore X-ray heating by the accreting supermassive black hole in Mrk 231 as a source of excitation for these lines, and find that it can reproduce the observed luminosities. We also consider a model with dense gas in a strong UV radiation field to produce the highest CO lines, but find that this model strongly overpredicts the hot dust mass in Mrk 231. Our favoured model consists of a star forming disk of radius 560 pc, containing clumps of dense gas exposed to strong UV radiation, dominating the emission of CO lines up to J = 8. X-rays from the accreting supermassive black hole in Mrk 231 dominate the excitation and chemistry of the inner disk out to a radius of 160 pc, consistent with the X-ray power of the AGN in Mrk 231. The extraordinary luminosity of the OH+ and H2O+ lines reveals the signature of X-ray driven excitation and chemistry in this region.
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17.
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18.
  • Buchbender, C., et al. (författare)
  • Dense gas in M 33 (HerM33es)
  • 2013
  • Ingår i: Astronomy and Astrophysics. - : EDP Sciences. - 0004-6361 .- 1432-0746. ; 549, s. 17-36
  • Tidskriftsartikel (refereegranskat)abstract
    • Aims. We aim to better understand the emission of molecular tracers of the diffuse and dense gas in giant molecular clouds and the influence that metallicity, optical extinction, density, far-UV field, and star formation rate have on these tracers.Methods. Using the IRAM 30 m telescope, we detected HCN, HCO+, 12CO, and 13CO in six GMCs along the major axis of M 33 at a resolution of ~114 pc and out to a radial distance of 3.4 kpc. Optical, far-infrared, and submillimeter data from Herschel and other observatories complement these observations. To interpret the observed molecular line emission, we created two grids of models of photon-dominated regions, one for solar and one for M 33-type subsolar metallicity.Results. The observed HCO+/HCN line ratios range between 1.1 and 2.5. Similarly high ratios have been observed in the Large Magellanic Cloud. The HCN/CO ratio varies between 0.4% and 2.9% in the disk of M 33. The 12CO/13CO line ratio varies between 9 and 15 similar to variations found in the diffuse gas and the centers of GMCs of the Milky Way. Stacking of all spectra allowed HNC and C2H to be detected. The resulting HCO+/HNC and HCN/HNC ratios of ~8 and 6, respectively, lie at the high end of ratios observed in a large set of (ultra-)luminous infrared galaxies. HCN abundances are lower in the subsolar metallicity PDR models, while HCO+ abundances are enhanced. For HCN this effect is more pronounced at low optical extinctions. The observed HCO+/HCN and HCN/CO line ratios are naturally explained by subsolar PDR models of low optical extinctions between 4 and 10 mag and of moderate densities of n 3 × 103–3 × 104 cm-3, while the FUV field strength only has a small effect on the modeled line ratios. The line ratios are almost equally well reproduced by the solar-metallicity models, indicating that variations in metallicity only play a minor role in influencing these line ratios.
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19.
  • Espada, D., et al. (författare)
  • Star Formation Efficiencies at Giant Molecular Cloud Scales in the Molecular Disk of the Elliptical Galaxy NGC 5128 (Centaurus A)
  • 2019
  • Ingår i: Astrophysical Journal. - : American Astronomical Society. - 1538-4357 .- 0004-637X. ; 887:1
  • Tidskriftsartikel (refereegranskat)abstract
    • We present ALMA CO (1-0) observations toward the dust lane of the nearest elliptical and radio galaxy, NGC 5128 (Centaurus A), with high angular resolution (similar to 1 '', or 18 pc), including information from large to small spatial scales and total flux. We find a total molecular gas mass of 1.6 x 10(9) M-circle dot and reveal the presence of filamentary components more extended than previously seen, up to a radius of 4 kpc. We find that the global star formation rate is similar to 1 M-circle dot yr(-1), which yields a star formation efficiency (SFE) of 0.6 Gyr(-1) (depletion time tau = 1.5 Gyr), similar to those in disk galaxies. We show the most detailed view to date (40 pc resolution) of the relation between molecular gas and star formation within the stellar component of an elliptical galaxy, from a scale of several kiloparsecs to the circumnuclear region close to the powerful radio jet. Although on average the SFEs are similar to those of spiral galaxies, the circumnuclear disk (CND) presents SFEs of 0.3 Gyr(-1), lower by a factor of 4 than the outer disk. The low SFE in the CND is in contrast to the high SFEs found in the literature for the circumnuclear regions of some nearby disk galaxies with nuclear activity, probably as a result of larger shear motions and longer active galactic nucleus feedback. The higher SFEs in the outer disk suggest that only central molecular gas or filaments with sufficient density and strong shear motions will remain in similar to 1 Gyr, which will later result in the compact molecular distributions and low SFEs usually seen in other giant ellipticals with cold gas.
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20.
  • Ginsburg, A., et al. (författare)
  • Dense gas in the Galactic central molecular zone is warm and heated by turbulence
  • 2016
  • Ingår i: Astronomy and Astrophysics. - : EDP Sciences. - 0004-6361 .- 1432-0746. ; 586, s. Art nr A50-
  • Tidskriftsartikel (refereegranskat)abstract
    • Context. The Galactic center is the closest region where we can study star formation under extreme physical conditions like those in high-redshift galaxies. Aims. We measure the temperature of the dense gas in the central molecular zone (CMZ) and examine what drives it. Methods. We mapped the inner 300 pc of the CMZ in the temperature-sensitive J = 3-2 para-formaldehyde (p-H2CO) transitions. We used the 3(2,1)-2(2,0)/3(0,3)-2(0,2) line ratio to determine the gas temperature in n similar to 10(4) - 10(5) cm(-3) gas. We have produced temperature maps and cubes with 30 0 0 and 1 km s(-1) resolution and published all data in FITS form. Results. Dense gas temperatures in the Galactic center range from similar to 60 K to > 100 K in selected regions. The highest gas temperatures T-G > 100 K are observed around the Sgr B2 cores, in the extended Sgr B2 cloud, the 20 km s(-1) and 50 km s(-1) clouds, and in "The Brick" (G0.253 + 0.016). We infer an upper limit on the cosmic ray ionization rate zeta(CR)
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21.
  • Gratier, P., et al. (författare)
  • Molecular and atomic gas in the Local Group galaxy M 33
  • 2010
  • Ingår i: Astronomy and Astrophysics. - : EDP Sciences. - 0004-6361 .- 1432-0746. ; 522:1
  • Tidskriftsartikel (refereegranskat)abstract
    • We present high-resolution large-scale observations of the molecular and atomic gas in the Local Group galaxy M 33. The observations were carried out using the HEterodyne Receiver Array (HERA) at the 30 m IRAM telescope in the CO(2-1) line, achieving a resolution of 12 '' x 2.6 km s(-1), enabling individual giant molecular clouds (GMCs) to be resolved. The observed region is 650 square arcminutes mainly along the major axis and out to a radius of 8.5 kpc, and covers entirely the 2' x 40' radial strip observed with the HIFI and PACS Spectrometers as part of the HERM33ES Herschel key program. The achieved sensitivity in main-beam temperature is 20-50 mK at 2.6 km s(-1) velocity resolution. The CO(2-1) luminosity of the observed region is 1.7 +/- 0.1 x 10(7) K km s(-1) pc(2) and is estimated to be 2.8 +/- 0.3 x 10(7) K km s(-1) pc(2) for the entire galaxy, corresponding to H-2 masses of 1.9 x 10(8) M-circle dot and 3.3 x 10(8) M-circle dot respectively (including He), calculated with N(H-2)/ICO(1-0) twice the Galactic value due to the half-solar metallicity of M 33. The HI 21 cm VLA archive observations were reduced, and the mosaic was imaged and cleaned using the multi-scale task in the CASA software package, yielding a series of datacubes with resolutions ranging from 5 '' to 25 ''. The HI mass within a radius of 8.5 kpc is estimated to be 1.4 x 10(9) M-circle dot. The azimuthally averaged CO surface brightness decreases exponentially with a scale length of 1.9 +/- 0.1 kpc whereas the atomic gas surface density is constant at Sigma(HI) = 6 +/- 2 M-circle dot pc(-2) deprojected to face-on. For an N(H-2)/ICO(1-0) conversion factor twice that of the Milky Way, the central kiloparsec H-2 surface density is Sigma(H2) = 8.5 +/- 0.2 M-circle dot pc(-2). The star formation rate per unit molecular gas (SF efficiency, the rate of transformation of molecular gas into stars), as traced by the ratio of CO to H-alpha and FIR brightness, is constant with radius. The SFE, with a N(H-2)/ICO(1-0) factor twice galactic, appears 2-4 times greater than for large spiral galaxies. A morphological comparison of molecular and atomic gas with tracers of star formation is presented showing good agreement between these maps both in terms of peaks and holes. A few exceptions are noted. Several spectra, including those of a molecular cloud situated more than 8 kpc from the galaxy center, are presented.
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22.
  • Hilchenbach, M., et al. (författare)
  • COMET 67P/CHURYUMOV-GERASIMENKO : CLOSE-UP on DUST PARTICLE FRAGMENTS
  • 2016
  • Ingår i: Astrophysical Journal Letters. - : Institute of Physics Publishing (IOPP). - 2041-8205 .- 2041-8213. ; 816:2
  • Tidskriftsartikel (refereegranskat)abstract
    • The COmetary Secondary Ion Mass Analyser instrument on board ESA's Rosetta mission has collected dust particles in the coma of comet 67P/Churyumov-Gerasimenko. During the early-orbit phase of the Rosetta mission, particles and particle agglomerates have been imaged and analyzed in the inner coma at distances between 100 km and 10 km off the cometary nucleus and at more than 3 AU from the Sun. We identified 585 particles of more than 14 μm in size. The particles are collected at low impact speeds and constitute a sample of the dust particles in the inner coma impacting and fragmenting on the targets. The sizes of the particles range from 14 μm up to sub-millimeter sizes and the differential dust flux size distribution is fitted with a power law exponent of -3.1. After impact, the larger particles tend to stick together, spread out or consist of single or a group of clumps, and the flocculent morphology of the fragmented particles is revealed. The elemental composition of the dust particles is heterogeneous and the particles could contain typical silicates like olivine and pyroxenes, as well as iron sulfides. The sodium to iron elemental ratio is enriched with regard to abundances in CI carbonaceous chondrites by a factor from ∼1.5 to ∼15. No clear evidence for organic matter has been identified. The composition and morphology of the collected dust particles appear to be similar to that of interplanetary dust particles.
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23.
  • Meijerink, R., et al. (författare)
  • Evidence for CO Shock Excitation in NGC 6240 from Herschel SPIRE Spectroscopy
  • 2013
  • Ingår i: Astrophysical Journal Letters. - 2041-8213 .- 2041-8205. ; 762:2, s. L16-L20
  • Tidskriftsartikel (refereegranskat)abstract
    • We present Herschel SPIRE FTS spectroscopy of the nearby luminous infrared galaxy NGC 6240. In total 20 linesare detected, including CO J = 4−3 through J = 13−12, 6 H2O rotational lines, and [C i] and [N ii] fine-structurelines. The CO to continuum luminosity ratio is 10 times higher in NGC 6240 than Mrk 231. Although the COladdersof NGC 6240 and Mrk 231 are very similar, UV and/or X-ray irradiation are unlikely to be responsible for theexcitation of the gas in NGC 6240.We applied both C and J shock models to the H2 v = 1–0 S(1) and v = 2–1 S(1)lines and the CO rotational ladder. The CO ladder is best reproduced by amodel with shock velocity vs = 10 km s−1and a pre-shock density nH = 5 × 104 cm−3. We find that the solution best fitting the H2 lines is degenerate. The shock velocities and number densities range between vs = 17–47 km s−1 and nH = 107–5×104 cm−3, respectively.The H2 lines thus need a much more powerful shock than the CO lines.We deduce that most of the gas is currently moderately stirred up by slow (10 km s−1) shocks while only a small fraction (1%) of the interstellar mediumis exposed to the high-velocity shocks. This implies that the gas is rapidly losing its highly turbulent motions. We argue that a high CO line-to-continuum ratio is a key diagnostic for the presence of shocks.
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24.
  • Michno, Wojciech, 1992, et al. (författare)
  • Structural amyloid plaque polymorphism is associated with distinct lipid accumulations revealed by trapped ion mobility mass spectrometry imaging
  • 2022
  • Ingår i: Journal of Neurochemistry. - : Wiley. - 0022-3042 .- 1471-4159. ; 160:4, s. 482-498
  • Tidskriftsartikel (refereegranskat)abstract
    • Understanding of Alzheimer's disease (AD) pathophysiology requires molecular assessment of how key pathological factors, specifically amyloid beta (A beta) plaques, influence the surrounding microenvironment. Here, neuronal lipids have been implicated in A beta plaque pathology, though the lipid microenvironment in direct proximity to A beta plaques is still not fully resolved. A further challenge is the microenvironmental molecular heterogeneity, across structurally polymorphic A beta features, such as diffuse, immature, and mature, fibrillary aggregates, whose resolution requires the integration of advanced, multimodal chemical imaging tools. Herein, we used matrix-assisted laser desorption/ionization trapped ion mobility spectrometry time-of-flight based mass spectrometry imaging (MALDI TIMS TOF MSI) in combination with hyperspectral confocal microscopy to probe the lipidomic microenvironment associated with structural polymorphism of A beta plaques in transgenic Alzheimer's disease mice (tgAPP(SWE)). Using on tissue and ex situ validation, TIMS MS/MS facilitated unambiguous identification of isobaric lipid species that showed plaque pathology-associated localizations. Integrated multivariate imaging data analysis revealed multiple, A beta plaque-enriched lipid patterns for gangliosides (GM), phosphoinositols (PI), phosphoethanolamines (PE), and phosphatidic acids (PA). Conversely, sulfatides (ST), cardiolipins (CL), and polyunsaturated fatty acid (PUFA)-conjugated phosphoserines (PS), and PE were depleted at plaques. Hyperspectral amyloid imaging further delineated the unique distribution of PA and PE species to mature plaque core regions, while PI, LPI, GM2 and GM3 lipids localized to immature A beta aggregates present within the periphery of A beta plaques. Finally, we followed AD pathology-associated lipid changes over time, identifying plaque- growth and maturation to be characterized by peripheral accumulation of PI (18:0/22:6). Together, these data demonstrate the potential of multimodal imaging approaches to overcome limitations associated with conventional advanced MS imaging applications. This allowed for the differentiation of both distinct lipid components in a complex micro-environment as well as their correlation to disease-relevant amyloid plaque polymorphs.
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25.
  • Mookerjea, B., et al. (författare)
  • The Herschel M 33 extended survey (HerM33es): PACS spectroscopy of the star-forming region BCLMP 302
  • 2011
  • Ingår i: Astronomy and Astrophysics. - : EDP Sciences. - 0004-6361 .- 1432-0746. ; 532, s. art. no. A152-
  • Tidskriftsartikel (refereegranskat)abstract
    • Context. The emission line of [CII] at 158 mu m is one of the strongest cooling lines of the interstellar medium (ISM) in galaxies. Aims. Distinguishing the relative contributions of the different ISM phases to [CII] emission is a major objective of the HerM33es program, a Herschel key project to study the ISM in the nearby spiral galaxy M 33. Methods. Using PACS, we have mapped the emission of [CII] 158 mu m, [OI] 63 mu m, and other FIR lines in a 2' x 2' region of the northern spiral arm of M 33, centered on the HII region BCLMP302. At the peak of Ha emission, we observed in addition a velocity-resolved [CII] spectrum using HIFI. We use scatterplots to compare these data with PACS 160 mu m continuum maps, and with maps of CO and HI data, at a common resolution of 12 '' or 50 pc. Maps of Ha and 24 mu m emission observed with Spitzer are used to estimate the SFR. We created maps of the [CII] and [OI] 63 mu m emission and detected [NII] 122 mu m and [NIII] 57 mu m at individual positions. Results. The [CII] line observed with HIFI is significantly broader than that of CO, and slightly blue-shifted. In addition, there is little spatial correlation between [CII] observed with PACS and CO over the mapped region. There is even less spatial correlation between [CII] and the atomic gas traced by HI. Detailed comparison of the observed intensities towards the HII region with models of photo-ionization and photon-dominated regions, confirms that a significant fraction, 20-30%, of the observed [CII] emission stems from the ionized gas and not from the molecular cloud. The gas heating efficiency, using the ratio of [CII] to the TIR as a proxy, varies between 0.07 and 1.5%, with the largest variations found outside the HII region.
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26.
  • Peripato, Vinicius, et al. (författare)
  • More than 10,000 pre-Columbian earthworks are still hidden throughout Amazonia
  • 2023
  • Ingår i: Science (New York, N.Y.). - 1095-9203. ; 382:6666, s. 103-109
  • Tidskriftsartikel (refereegranskat)abstract
    • Indigenous societies are known to have occupied the Amazon basin for more than 12,000 years, but the scale of their influence on Amazonian forests remains uncertain. We report the discovery, using LIDAR (light detection and ranging) information from across the basin, of 24 previously undetected pre-Columbian earthworks beneath the forest canopy. Modeled distribution and abundance of large-scale archaeological sites across Amazonia suggest that between 10,272 and 23,648 sites remain to be discovered and that most will be found in the southwest. We also identified 53 domesticated tree species significantly associated with earthwork occurrence probability, likely suggesting past management practices. Closed-canopy forests across Amazonia are likely to contain thousands of undiscovered archaeological sites around which pre-Columbian societies actively modified forests, a discovery that opens opportunities for better understanding the magnitude of ancient human influence on Amazonia and its current state.
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27.
  • Rosenberg, M. J. F., et al. (författare)
  • The Herschel Comprehensive (U)lirg Emission Survey (Hercules): Co Ladders, Fine Structure Lines, and Neutral Gas Cooling
  • 2015
  • Ingår i: Astrophysical Journal. - : American Astronomical Society. - 1538-4357 .- 0004-637X. ; 801:2
  • Tidskriftsartikel (refereegranskat)abstract
    • (Ultra) luminous infrared galaxies ((U)LIRGs) are objects characterized by their extreme infrared (8-1000 mu m) luminosities (L-LIRG > 10(11) L-circle dot and L-ULIRG > 10(12) L-circle dot). The Herschel Comprehensive ULIRG Emission Survey (PI: van derWerf) presents a representative flux-limited sample of 29 (U)LIRGs that spans the full luminosity range of these objects (10(11)L(circle dot)
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28.
  • Tang, X. D., et al. (författare)
  • Kinetic temperature of massive star-forming molecular clumps measured with formaldehyde: IV. The ALMA view of N113 and N159W in the LMC
  • 2021
  • Ingår i: Astronomy and Astrophysics. - : EDP Sciences. - 0004-6361 .- 1432-0746. ; 655
  • Tidskriftsartikel (refereegranskat)abstract
    • We mapped the kinetic temperature structure of two massive star-forming regions, N113 and N159W, in the Large Magellanic Cloud (LMC). We have used 1.6 (0.4 pc) resolution measurements of the para-H2CO JKaKc = 303-202, 322-221, and 321-220 transitions near 218.5 GHz to constrain RADEX non local thermodynamic equilibrium models of the physical conditions. The gas kinetic temperatures derived from the para-H2CO line ratios 322-221/303-202 and 321-220/303-202 range from 28 to 105 K in N113 and 29 to 68 K in N159W. Distributions of the dense gas traced by para-H2CO agree with those of the 1.3 mm dust and Spitzer 8.0 μm emission, but they do not significantly correlate with the Hα emission. The high kinetic temperatures (Tkin50 K) of the dense gas traced by para-H2CO appear to be correlated with the embedded infrared sources inside the clouds and/or young stellar objects in the N113 and N159W regions. The lower temperatures (Tkin < 50 K) were measured at the outskirts of the H2CO-bearing distributions of both N113 and N159W. It seems that the kinetic temperatures of the dense gas traced by para-H2CO are weakly affected by the external sources of the Hα emission. The non thermal velocity dispersions of para-H2CO are well correlated with the gas kinetic temperatures in the N113 region, implying that the higher kinetic temperature traced by para-H2CO is related to turbulence on a 0.4 pc scale. The dense gas heating appears to be dominated by internal star formation activity, radiation, and/or turbulence. It seems that the mechanism heating the dense gas of the star-forming regions in the LMC is consistent with that in Galactic massive star-forming regions located in the Galactic plane.
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29.
  • Ao, Y., et al. (författare)
  • Deep Submillimeter and Radio Observations in the SSA22 Field. I. Powering Sources and the Ly alpha Escape Fraction of Ly alpha Blobs
  • 2017
  • Ingår i: Astrophysical Journal. - : American Astronomical Society. - 0004-637X .- 1538-4357. ; 850:2
  • Tidskriftsartikel (refereegranskat)abstract
    • We study the heating mechanisms and Ly alpha escape fractions of 35 Ly alpha blobs (LABs) at z approximate to 3.1 in the SSA22 field. Dust continuum sources have been identified in 11 of the 35 LABs, all with star formation rates (SFRs) above 100M(circle dot) yr(-1). Likely radio counterparts are detected in 9 out of 29 investigated LABs. The detection of submillimeter dust emission is more linked to the physical size of the Ly alpha emission than to the Ly alpha luminosities of the LABs. A radio excess in the submillimeter/ radio-detected LABs is common, hinting at the presence of active galactic nuclei. Most radio sources without X-ray counterparts are located at the centers of the LABs. However, all X-ray counterparts avoid the central regions. This may be explained by absorption due to exceptionally large column densities along the line-of-sight or by LAB morphologies, which are highly orientation dependent. The median Lya escape fraction is about 3% among the submillimeter-detected LABs, which is lower than a lower limit of 11% for the submillimeter-undetected LABs. We suspect that the large difference is due to the high dust attenuation supported by the large SFRs, the dense large-scale environment as well as large uncertainties in the extinction corrections required to apply when interpreting optical data.
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30.
  • Burillo, S. G., et al. (författare)
  • ALMA images the many faces of the NGC 1068 torus and its surroundings
  • 2019
  • Ingår i: Astronomy and Astrophysics. - : EDP Sciences. - 0004-6361 .- 1432-0746. ; 632
  • Tidskriftsartikel (refereegranskat)abstract
    • Aims. We investigate the fueling and the feedback of nuclear activity in the nearby (D = 14 Mpc) Seyfert 2 barred galaxy NGC 1068 by studying the distribution and kinematics of molecular gas in the torus and its connections to the host galaxy disk. Methods.We used the Atacama Large Millimeter Array (ALMA ) to image the emission of a set of molecular gas tracers in the circumnuclear disk (CND) and the torus of the galaxy using the CO(2-1), CO(3-2), and HCO+(4-3) lines and their underlying continuum emission with high spatial resolutions (0:0300 0:0900 ' 26 pc). These transitions, which span a wide range of physical conditions of molecular gas (n(H2) 103107 cm3), are instrumental in revealing the density radial stratification and the complex kinematics of the gas in the torus and its surroundings. Results. The ALMA images resolve the CND as an asymmetric ringed disk of D ' 400 pc in size and '1:4 108 M in mass. The CND shows a marked deficit of molecular gas in its central '130 pc region. The inner edge of the ring is associated with the presence of edge-brightened arcs of NIR polarized emission, which are identified with the current working surface of the ionized wind of the active galactic nucleus (AGN). ALMA proves the existence of an elongated molecular disk/torus in NGC 1068 of Mgas torus ' 3 105 M, which extends over a large range of spatial scales D ' 1030 pc around the central engine. The new observations evidence the density radial stratification of the torus: the HCO+(4-3) torus, with a full size DHCO+(43) = 11 0:6 pc, is a factor of between two and three smaller than its CO(2-1) and CO(3-2) counterparts, which have full sizes of DCO(32) = 26 0:6 pc and DCO(21) = 28 0:6 pc, respectively. This result brings into light the many faces of the molecular torus. The torus is connected to the CND through a network of molecular gas streamers detected inside the CND ring. The kinematics of molecular gas show strong departures from circular motions in the torus, the gas streamers, and the CND ring. These velocity field distortions are interconnected and are part of a 3D outflow that reflects the eects of AGN feedback on the kinematics of molecular gas across a wide range of spatial scales around the central engine. In particular, we estimate through modeling that a significant fraction of the gas inside the torus ('0:40:6 Mgas torus) and a comparable amount of mass along the gas streamers are outflowing. However, the bulk of the mass, momentum, and energy of the molecular outflow of NGC 1068 is contained at larger radii in the CND region, where the AGN wind and the radio jet are currently pushing the gas assembled at the Inner Lindblad Resonance (ILR) ring of the nuclear stellar bar. Conclusions. In our favored scenario a wide-angle AGN wind launched from the accretion disk of NGC1068 is currently impacting a sizable fraction of the gas inside the torus. However, a large gas reservoir ('1:21:8 105 M), which lies close to the equatorial plane of the torus, remains unaected by the feedback of the AGN wind and can therefore continue fueling the AGN for at least '14 Myr. Nevertheless, AGN fueling currently seems thwarted on intermediate scales (15 pc r 50 pc).
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31.
  • Burillo, S. G., et al. (författare)
  • ALMA imaging of C2H emission in the disk of NGC 1068
  • 2017
  • Ingår i: Astronomy and Astrophysics. - : EDP Sciences. - 0004-6361 .- 1432-0746. ; 608, s. A56-
  • Tidskriftsartikel (refereegranskat)abstract
    • Aims. We study the feedback of star formation and nuclear activity on the chemistry of molecular gas in NGC 1068, a nearby (D = 14 Mpc) Seyfert 2 barred galaxy, by analyzing whether the abundances of key molecular species such as ethynyl (C2H), which is a classical tracer of photon dominated regions (PDR), change in the different environments of the disk of the galaxy. Methods. We used the Atacama Large Millimeter Array (ALMA) to map the emission of the hyperfine multiplet of C2H(N = 1-0) and its underlying continuum emission in the central r similar or equal to 35" (2.5 kpc) region of the disk of NGC 1068 with a spatial resolution 1.0 x 0.7 (similar or equal to 50-70 pc). We used maps of the dust continuum emission obtained at 349 GHz by ALMA to derive the H-2 gas column densities and combined these with the C2H map at matched spatial resolution to estimate the fractional abundance of this species. We developed a set of time-dependent chemical models, which include shocks, gas-phase PDRs, and gas-grain chemical models to determine the origin of the C2H gas. Results. A sizeable fraction of the total C2H line emission is detected from the r similar or equal to 1.3 kpc starburst (SB) ring, which is a region that concentrates the bulk of the recent massive star formation in the disk traced by the Pa alpha emission complexes imaged by the Hubble Space Telescope (HST). However, the brightest C2H emission originates from a r similar or equal to 200 pc off -centered circumnuclear disk (CND), where evidence of a molecular outflow has been previously found in other molecular tracers imaged by ALMA. We also detect significant emission that connects the CND with the outer disk in a region that probes the interface between the molecular disk and ionized gas outflow out to r similar or equal to 400 pc. We derived the fractional abundances of C2H (X(C2H)) assuming local thermodynamic equilibrium (LTE) conditions and a set of excitation temperatures (T-ex) constrained by the previous multiline CO studies of the galaxy. Our estimates range from X(C2H) similar or equal to a few 10(-8) in the SB ring up to X(C2H) similar or equal to a few 10(-7) in the outflow region. The PDR models that incorporate gas-grain chemistry are able to account for X(C2H) in the SB ring for moderately dense (n(H-2) >= 10(4) cm(-3)) and moderately UV-irradiated gas (UV-field = 10(4-5) cm(-3)). Conclusions. We find that the transient conditions required to fit the high values of X(C2H) in the outflow are likely due to UV or X-ray irradiated non-dissociative shocks associated with the highly turbulent interface between the outflow and molecular gas in NGC 1068. Although the inferred local timescales are short, the erosion of molecular clouds by the active galactic nucleus (AGN) wind and/or the jet likely resupplies the interface working surface continuously, making a nearly steady state persist in the disk of the galaxy.
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32.
  • Burillo, S. G., et al. (författare)
  • ALMA resolves the torus of NGC 1068: Continuum and molecular line emission
  • 2016
  • Ingår i: Astrophysical Journal Letters. - : American Astronomical Society. - 2041-8213 .- 2041-8205. ; 823:1, s. Art. no. L12-
  • Tidskriftsartikel (refereegranskat)abstract
    • We used the Atacama Large Millimeter Array (ALMA) to map the emission of the CO(6-5) molecular line and the 432 mu m continuum emission from the 300 pc sized circumnuclear disk (CND) of the nearby Seyfert 2 galaxy NGC 1068 with a spatial resolution of similar to 4 pc. These observations spatially resolve the CND and, for the first time, image the dust emission, the molecular gas distribution, and the kinematics from a 7-10 pc diameter disk that represents the submillimeter counterpart of the putative torus of NGC 1068. We fitted the nuclear spectral energy distribution of the torus using ALMA and near-and mid-infrared (NIR/MIR) data with CLUMPY torus models. The mass and radius of the best-fit solution for the torus are both consistent with the values derived from the ALMA data alone: M-gas(torus) = (1 +/- 0.3) x 10(5) M-circle dot and R-torus = 3.5 +/- 0.5 pc. The dynamics of the molecular gas in the torus show strong non-circular motions and enhanced turbulence superposed on a surprisingly slow rotation pattern of the disk. By contrast with the nearly edge-on orientation of the H2O megamaser disk, we found evidence suggesting that the molecular torus is less inclined (i = 34 degrees-66 degrees) at larger radii. The lopsided morphology and complex kinematics of the torus could be the signature of the Papaloizou-Pringle instability, long predicted to likely drive the dynamical evolution of active galactic nuclei tori.
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33.
  • Burillo, S. G., et al. (författare)
  • Molecular line emission in NGC 1068 imaged with ALMA : I. An AGN-driven outflow in the dense molecular gas
  • 2014
  • Ingår i: Astronomy and Astrophysics. - : EDP Sciences. - 0004-6361 .- 1432-0746. ; 567, s. 125-
  • Tidskriftsartikel (refereegranskat)abstract
    • Aims. We investigate the fueling and the feedback of star formation and nuclear activity in NGC 1068, a nearby (D = 14 Mpc) Seyfert 2 barred galaxy, by analyzing the distribution and kinematics of the molecular gas in the disk. We aim to understand if and how gas accretion can self-regulate.Methods. We have used the Atacama Large Millimeter Array (ALMA) to map the emission of a set of dense molecular gas (n(H2) ' 1056 cm3) tracers (CO(3-2), CO(6-5), HCN(4-3), HCO+(4-3), and CS(7-6)) and their underlying continuum emission in the central r ∼ 2 kpc of NGC 1068 with spatial resolutions ∼0:3000:500 (∼20-35 pc for the assumed distance of D = 14 Mpc). Results. The sensitivity and spatial resolution of ALMA give an unprecedented detailed view of the distribution and kinematics of the dense molecular gas (n(H2) ≈ 1056cm3) in NGC 1068. Molecular line and dust continuum emissions are detected from a r ∼ 200 pc off-centered circumnuclear disk (CND), from the 2.6 kpc-diameter bar region, and from the r ∼ 1:3 kpc starburst (SB) ring. Most of the emission in HCO+, HCN, and CS stems from the CND. Molecular line ratios show dramatic order-of-magnitude changes inside the CND that are correlated with the UV/X-ray illumination by the active galactic nucleus (AGN), betraying ongoing feedback. We used the dust continuum fluxes measured by ALMA together with NIR/MIR data to constrain the properties of the putative torus using CLUMPY models and found a torus radius of 20+6 10 pc. The Fourier decomposition of the gas velocity field indicates that rotation is perturbed by an inward radial flow in the SB ring and the bar region. However, the gas kinematics from r ∼ 50 pc out to r ∼ 400 pc reveal a massive (Mmol ∼ 2:7+0:9 1:2 × 107 M) outflow in all molecular tracers. The tight correlation between the ionized gas outflow, the radio jet, and the occurrence of outward motions in the disk suggests that the outflow is AGN driven. Conclusions. The molecular outflow is likely launched when the ionization cone of the narrow line region sweeps the nuclear disk. The outflow rate estimated in the CND, dM=dt ∼ 63+21 37 M yr1, is an order of magnitude higher than the star formation rate at these radii, confirming that the outflow is AGN driven. The power of the AGN is able to account for the estimated momentum and kinetic luminosity of the outflow. The CND mass load rate of the CND outflow implies a very short gas depletion timescale of ≤1 Myr. The CND gas reservoir is likely replenished on longer timescales by efficient gas inflow from the outer disk. © ESO 2014.
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34.
  • Espada, D., et al. (författare)
  • Disentangling the Circumnuclear Environs of Centaurus A. III. An Inner Molecular Ring, Nuclear Shocks, and the CO to Warm H-2 Interface
  • 2017
  • Ingår i: Astrophysical Journal. - : American Astronomical Society. - 1538-4357 .- 0004-637X. ; 843:2
  • Tidskriftsartikel (refereegranskat)abstract
    • We present the distribution and kinematics of the molecular gas in the circumnuclear disk (CND; 400 pc ×200 pc) of Centaurus A with resolutions of ∼5 pc (0.″3) and shed light onto the mechanism feeding the active galactic nucleus (AGN) using CO(3-2), HCO + (4-3), HCN(4-3), and CO(6-5) observations obtained with ALMA. Multiple filaments or streamers of tens to a hundred parsec scale exist within the CND, which form a ring-like structure with an unprojected diameter of 9″ ×6″ (162 pc ×108 pc) and a position angle P.A. ≃ 155°. Inside the nuclear ring, there are two leading and straight filamentary structures with lengths of about 30-60 pc at P.A. ≃ 120° on opposite sides of the AGN, with a rotational symmetry of 180° and steeper position-velocity diagrams, which are interpreted as nuclear shocks due to non-circular motions. Along the filaments, and unlike other nearby AGNs, several dense molecular clumps present low HCN/HCO + (4-3) ratios (≲0.5). The filaments abruptly end in the probed transitions at r ≃ 20 pc from the AGN, but previous near-IR H 2 (J = 1-0)S(1) maps show that they continue in an even warmer gas phase (T ∼ 1000 K), winding up in the form of nuclear spirals, and forming an inner ring structure with another set of symmetric filaments along the N-S direction and within r ≃ 10 pc. The molecular gas is governed primarily by non-circular motions, being the successive shock fronts at different scales where loss of angular momentum occurs, a mechanism that may feed efficiently powerful radio galaxies down to parsec scales.
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35.
  • Falstad, Niklas, 1987, et al. (författare)
  • CON-quest: Searching for the most obscured galaxy nuclei
  • 2021
  • Ingår i: Astronomy and Astrophysics. - : EDP Sciences. - 0004-6361 .- 1432-0746. ; 649
  • Tidskriftsartikel (refereegranskat)abstract
    • Context. Some luminous and ultraluminous infrared galaxies (LIRGs and ULIRGs) host extremely compact (r < 100 pc) and dusty nuclei. The high extinction associated with large column densities of gas and dust toward these objects render them hard to detect at many wavelengths. The intense infrared radiation arising from warm dust in these sources can provide a significant fraction of the bolometric luminosity of the galaxy and is prone to excite vibrational levels of molecules such as HCN. This results in emission from the rotational transitions of vibrationally excited HCN (HCN-vib); the brightest emission is found in compact obscured nuclei (CONs; ςHCN-vib > 1 L⊙ pc-2 in the J = 3-2 transition). However, there have been no systematic searches for CONs, and it is unknown how common they are. Aims. We aim to establish how common CONs are in the local Universe (z < 0.08), and whether their prevalence depends on the luminosity or other properties of the host galaxy. Methods. We conducted an Atacama Large Millimeter/submillimeter Array survey of the rotational J = 3-2 transition of HCN-vib in a volume-limited sample of 46 far-infrared luminous galaxies. Results. Compact obscured nuclei are identified in 38-13+18% of the ULIRGs, 21-6+12% of the LIRGs, and 0-0+9% of the lower luminosity galaxies. We find no dependence on the inclination of the host galaxy, but strong evidence of lower IRAS 25 μm to 60 μm flux density ratios (f25/f60) in CONs (with the exception of one galaxy, NGC 4418) compared to the rest of the sample. Furthermore, we find that CONs have stronger silicate features (s9.7 μm), but similar polycyclic aromatic hydrocarbon equivalent widths (EQW6.2 μm) compared to other galaxies. Along with signatures of molecular inflows seen in the far-infrared in most CONs, submillimeter observations also reveal compact, often collimated, outflows. Conclusions. In the local Universe, CONs are primarily found in (U)LIRGs, in which they are remarkably common. As such systems are often highly disturbed, inclinations are difficult to estimate, and high-resolution continuum observations of the individual nuclei are required to determine if the CON phenomenon is related to the inclinations of the nuclear disks. Further studies of the in- A nd outflow properties of CONs should also be conducted to investigate how these are connected to each other and to the CON phenomenon. The lower f25/f60 ratios in CONs as well as the results for the mid-infrared diagnostics investigated (EQW6.2 μm and s9.7 μm) are consistent with the notion that large dust columns gradually shift the radiation from the hot nucleus to longer wavelengths, making the mid- A nd far-infrared "photospheres"significantly cooler than the interior regions. Finally, to assess the importance of CONs in the context of galaxy evolution, it is necessary to extend this study to higher redshifts where (U)LIRGs are more common.
  •  
36.
  • Henkel, C., et al. (författare)
  • Carbon and oxygen isotope ratios in starburst galaxies: New data from NGC 253 and Mrk 231 and their implications
  • 2014
  • Ingår i: Astronomy and Astrophysics. - : EDP Sciences. - 0004-6361 .- 1432-0746. ; 565
  • Tidskriftsartikel (refereegranskat)abstract
    • Carbon and oxygen isotope ratios are excellent measures of nuclear processing, but few such data have been taken toward extragalactic targets so far. Therefore, using the IRAM 30-m telescope, CN and CO isotopologues have been measured toward the nearby starburst galaxy NGC 253 and the prototypical ultraluminous infrared galaxy Mrk 231. Toward the center of NGC 253, the CN and (CN)-C-13 N = 1 -> 0 lines indicate no significant deviations from expected local thermodynamical equilibrium after accounting for moderate saturation effects (10 and 25%) in the two detected spectral components of the main species. Including calibration uncertainties, which dominate the error budget, the C-12/C-13 ratio becomes 40 +/- 10. This is larger than the ratio in the central molecular zone of the Galaxy, suggesting a higher infall rate of poorly processed gas toward the central region. Assuming that the ratio also holds for the CO emitting gas, this yields O-16/O-18 = 145 +/- 36 and O-16/O-17 = 1290 +/- 365 and a S-32/S-34 ratio close to the one measured for the local interstellar medium (2025). No indication of vibrationally excited CN is found in the lower frequency fine structure components of the N = 1 -> 0 and 2 -> 1 transitions at rms noise levels of 3 and 4 mK (15 and 20 mJy) in 8.5 km s-1 wide channels. Peak line intensity ratios between NGC 253 and Mrk 231 are similar to 100 for (CO)-C-12-O-16 and (CO)-C-12-O-18 J = 1 -> 0, while the ratio for (CO)-C-13-O-16 J = 1 -> 0 is similar to 250. This and similar (CO)-C-13 and (CO)-O-18 line intensities in the J = 1 -> 0 and 2 -> 1 transitions of Mrk 231 suggest C-12/C-13 similar to 100 and O-16/O-18 similar to 100, in agreement with values obtained for the less evolved ultraluminous merger Arp 220. Also, when accounting for other (scarcely available) extragalactic data, C-12/C-13 ratios appear to vary over a full order of magnitude, from >100 in ultraluminous high redshift galaxies to similar to 100 in more local such galaxies to similar to 40 in weaker starbursts that are not undergoing a large scale merger to 25 in the central molecular zone of the Milky Way. With C-12 being predominantly synthesized in massive stars, while C-13 is mostly ejected by longer lived lower mass stars at later times, this is qualitatively consistent with our results of decreasing carbon isotope ratios with time and rising metallicity. It is emphasized, however, that both infall of poorly processed material, initiating a nuclear starburst, and the ejecta from newly formed massive stars (in particular in the case of a top-heavy stellar initial mass function) can raise the carbon isotope ratio for a limited amount of time.
  •  
37.
  • Henkel, C., et al. (författare)
  • Molecular line emission in NGC 4945, imaged with ALMA
  • 2018
  • Ingår i: Astronomy and Astrophysics. - : EDP Sciences. - 0004-6361 .- 1432-0746. ; 615
  • Tidskriftsartikel (refereegranskat)abstract
    • NGC 4945 is one of the nearest (D ≈ 3.8 Mpc; 1 00 ≈ 19 pc) starburst galaxies. To investigate the structure, dynamics, and composition of the dense nuclear gas of this galaxy, ALMA band 3 (λ ≈ 3−4 mm) observations were carried out with ≈2 00 resolution. Three HCN and two HC + isotopologues, CS, C 3 H 2 , SiO, HCO, and CH 3 C 2 H were measured. Spectral line imaging demonstrates the presence of a rotating nuclear disk of projected size 10 00 × 2 00 reaching out to a galactocentric radius of r ≈ 100 pc with position angle PA = 45 ◦ ± 2 ◦ , inclination i = 75 ◦ ± 2 ◦ and an unresolved bright central core of size <∼ 2 00 . The continuum source, representing mostly free-free radiation from star forming regions, is more compact than the nuclear disk by a linear factor of two but shows the same position angle and is centered 0 00 . 39 ± 0 00 . 14 northeast of the nuclear accretion disk defined by H 2 O maser emission. Near the systemic velocity but outside the nuclear disk, both HCN J = 1 → 0 and CS J = 2 → 1 delineate molecular arms of length >∼ 15 00 ( >∼ 285 pc) on opposite sides of the dynamical center. These are connected by a (deprojected) ≈ 0.6 kpc sized molecular bridge, likely a dense gaseous bar seen almost ends-on, shifting gas from the front and back side into the nuclear disk. Modeling this nuclear disk located farther inside (r <∼ 100 pc) with tilted rings provides a good fit by inferring a coplanar outflow reaching a characteristic deprojected velocity of ≈50 km s −1 . All our molecular lines, with the notable exception of CH 3 C 2 H, show significant absorption near the systemic velocity (≈571 km s −1 ), within the range ≈500-660 km s −1 . Apparently, only molecular transitions with low critical H 2 density (n crit<∼ 10 4 cm −3 ) do not show absorption. The velocity field of the nuclear disk, derived from CH 3 C 2 H, provides evidence for rigid rotation in the inner few arcseconds and a dynamical mass of M tot = (2.1 ± 0.2) × 10 8 M inside a galactocentric radius of 2 00 . 45 (≈45 pc), with a significantly flattened rotation curve farther out. Velocity integrated line intensity maps with most pronounced absorption show molecular peak positions up to ≈1 00 . 5 (≈30 pc) southwest of the continuum peak, presumably due to absorption, which appears to be most severe slightly northeast of the nuclear maser disk. A nitrogen isotope ratio of 14 N/ 15 N ≈ 200-450 is estimated. This range of values is much higher then previously reported on a tentative basis. Therefore, because 15 N is less abundant than expected, the question for strong 15 N enrichment by massive star ejecta in starbursts still remains to be settled.
  •  
38.
  • Kimani, N., et al. (författare)
  • Radio evolution of supernova SN 2008iz in M 82
  • 2016
  • Ingår i: Astronomy and Astrophysics. - : EDP Sciences. - 0004-6361 .- 1432-0746. ; 593
  • Tidskriftsartikel (refereegranskat)abstract
    • We report on multi-frequency Very Large Array (VLA) and Very Long Baseline Interferometry (VLBI) radio observations for a monitoring campaign of supernova SN 2008iz in the nearby irregular galaxy M 82. We fit two models to the data, a simple time power-law, S ât?, and a simplified Weiler model, yielding decline indices of ? =-1.22 ± 0.07 (days 100-1500) and-1.41 ± 0.02 (days 76-2167), respectively. The late-time radio light-curve evolution shows flux-density flares at ?970 and ?1400 days that are a factor of ?2 and ?4 higher than the expected flux, respectively. The later flare, except for being brighter, does not show signs of decline at least from results examined so far (2014 January 23; day 2167). We derive the spectral index, ?, S â?? for frequencies 1.4 to 43 GHz for SN 2008iz during the period from 430 to 2167 days after the supernova explosion. The value of ? shows no signs of evolution and remains steep â‰-1 throughout the period, unlike that of SN 1993J, which started flattening at day 970. From the 4.8 and 8.4 GHz VLBI images, the supernova expansion is seen to start with a shell-like structure that becomes increasingly more asymmetric, then breaks up in the later epochs, with bright structures dominating the southern part of the ring. This structural evolution differs significantly from SN 1993J, which remains circularly symmetric over 4000 days after the explosion. The VLBI 4.8 and 8.4 GHz images are used to derive a deceleration index, m, for SN 2008iz, of 0.86 ± 0.02, and the average expansion velocity between days 73 and 1400 as (12.1 ± 0.2) × 103 km s-1. From the energy equipartition between magnetic field and particles, we estimate the minimum total energy in relativistic particles and the magnetic fields during the supernova expansion and also find the magnetic field amplification factor for SN 2008iz to be in the range of 55-400.
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39.
  • Miura, R.E., et al. (författare)
  • A giant molecular cloud catalogue in the molecular disc of the elliptical galaxy NGC 5128 (Centaurus A)
  • 2021
  • Ingår i: Monthly Notices of the Royal Astronomical Society. - : Oxford University Press (OUP). - 0035-8711 .- 1365-2966. ; 504:4, s. 6198-6215
  • Tidskriftsartikel (refereegranskat)abstract
    • We present the first census of giant molecular clouds (GMCs) complete down to 106 M⊙ and within the inner 4 kpc of the nearest giant elliptical and powerful radio galaxy, Centaurus A. We identified 689 GMCs using CO(1-0) data with 1 arcsec spatial resolution (∼20 pc) and 2 km s-1 velocity resolution obtained with the Atacama Large Millimeter/submillimeter Array. The I(CO)-N(H2) conversion factor based on the virial method is XCO = (2 ± 1) × 1020 cm-2(K km s-1)-1 for the entire molecular disc, consistent with that of the discs of spiral galaxies including the Milky Way, and XCO = (5 ± 2) × 1020 cm-2(K km s-1)-1 for the circumnuclear disc (CND; within a galactocentric radius of 200 pc). We obtained the GMC mass spectrum distribution and find that the best truncated power-law fit for the whole molecular disc, with index γ≃ -2.41 ± 0.02 and upper cut-off mass $\sim \! 1.3\times 10^{7}\, \mathrm{M}_{\odot }$, is also in agreement with that of nearby disc galaxies. A trend is found in the mass spectrum index from steep to shallow as we move to inner radii. Although the GMCs are in an elliptical galaxy, the general GMC properties in the molecular disc are as in spiral galaxies. However, in the CND, large offsets in the line-width-size scaling relations (∼0.3 dex higher than those in the GMCs in the molecular disc), a different XCO factor, and the shallowest GMC mass distribution shape (γ= -1.1 ± 0.2) all suggest that there the GMCs are most strongly affected by the presence of the active galactic nucleus and/or shear motions.
  •  
40.
  • Nishimura, Y., et al. (författare)
  • CON-quest: II. Spatially and spectrally resolved HCN/HCO + line ratios in local luminous and ultraluminous infrared galaxies
  • 2024
  • Ingår i: Astronomy and Astrophysics. - 0004-6361 .- 1432-0746. ; 686
  • Tidskriftsartikel (refereegranskat)abstract
    • Context. Nuclear regions of ultraluminous and luminous infrared galaxies (U/LIRGs) are powered by starbursts and/or active galactic nuclei (AGNs). These regions are often obscured by extremely high columns of gas and dust. Molecular lines in the submillimeter windows have the potential to determine the physical conditions of these compact obscured nuclei (CONs). Aims. We aim to reveal the distributions of HCN and HCO+ emission in local U/LIRGs and investigate whether and how they are related to galaxy properties. Methods. Using the Atacama Large Millimeter/submillimeter Array (ALMA), we have conducted sensitive observations of the HCN J = 3-2 and HCO+J = 3-2 lines toward 23 U/LIRGs in the local Universe (z < 0.07) with a spatial resolution of ~0.3″ ( ~50-400 pc). Results. We detected both HCN and HCO+ in 21 galaxies, only HCN in one galaxy, and neither in one galaxy. The global HCN/HCO+ line ratios, averaged over scales of ~0.5-4 kpc, range from 0.4 to 2.3, with an unweighted mean of 1.1. These line ratios appear to have no systematic trend with bolometric AGN luminosity or star formation rate. The line ratio varies with position and velocity within each galaxy, with an average interquartile range of 0.38 on a spaxel-by-spaxel basis. In eight out of ten galaxies known to have outflows and/or inflows, we found spatially and kinematically symmetric structures of high line ratios. These structures appear as a collimated bicone in two galaxies and as a thin spherical shell in six galaxies. Conclusions. Non-LTE analysis suggests that the high HCN/HCO+ line ratio in outflows is predominantly influenced by the abundance ratio. Chemical model calculations indicate that the enhancement of HCN abundance in outflows is likely due to high-temperature chemistry triggered by shock heating. These results imply that the HCN/HCO+ line ratio can aid in identifying the outflow geometry when the shock velocity of the outflows is sufficiently high to heat the gas.
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41.
  • Ott, Jürgen, et al. (författare)
  • Cm and mm Survey of Molecular Absorption Lines in Centaurus A
  • 2012
  • Ingår i: American Astronomical Society, AAS Meeting. ; 219, s. 349.26-
  • Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
    • We present Australia Telescope Array data of molecular absorption lines toward the bright central core of Centaurus A. The line of sight crosses the prominent dust lane and continues through the disk and eventually through gas that may be very close to the central supermassive black hole. The goal of our the survey is to determine the physical conditions of the gas via analyses of molecular line tracers including molecular abundances and excitation that is sensitive to changes in temperature, density, ionization, and shocks. This study allows us to derive the physical conditions of every absorption line complex and finally let us assign the most likely environments. We present ATCA data in the 20-50GHz range at medium resolution of a few km/s and possibly ALMA data at 3mm and 1mm wavelengths. The project continues with sub-km/s higher spectral resolution for the most important lines in 2012.
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42.
  • Reimold, W U, et al. (författare)
  • Laser argon dating of melt breccias from the Siljan impact structure, Sweden : Implications for a possible relationship to Late Devonian extinction events
  • 2005
  • Ingår i: Meteoritics and Planetary Science. - : Wiley. - 1086-9379 .- 1945-5100. ; 40:4, s. 591-607
  • Tidskriftsartikel (refereegranskat)abstract
    • In earlier studies, the 65-75 km diameter Si1jan impact structure in Sweden has been linked to the Late Devonian mass extinction event. The Siljan impact event has previously been dated by K-Ar and Ar-Ar chronology at 342-368 Ma, with the commonly quoted age being 362.7 +/- 2.2 Ma (2 sigma, recalculated using currently accepted decay constants). Until recently, the accepted age for the Frasnian/Famennian boundary and associated extinction event was 364 Ma, which is within error limits of this earlier Si1jan age. Here we report new Ar-Ar ages extracted by laser spot and laser step heating techniques for several melt breccia samples from Si1jan (interpreted to be impact melt breccia). The analytical results show some scatter, which is greater in samples with more extensive alteration; these samples generally yield younger ages. The two samples with the least alteration yield the most reproducible weighted mean ages: one yielded a laser spot age of 377.2 +/- 2.5 Ma (95% confidence limits) and the other yielded both a laser spot age of 376.1 +/- 2.8 Ma (95% confidence limits) and a laser stepped heating plateau age over 70.6% (39)Ar release of 377.5 +/- 2.4 Ma (2 sigma). Our conservative estimate for the age of Siljan is 377 2 Ma (95% confidence limits), which is significantly different from both the previously accepted age for the Frasnian/Famennian (F/F) boundary and the previously quoted age of Siljan. However, the age of the F/F boundary has recently been revised to 374.5 +/- 2.6 Ma by the International Commission for Stratigraphy, which is, within error, the same as our new age. However, the currently available age data are not proof that there was a connection between the Si1jan impact event and the F/F boundary extinction. This new result highlights the dual problems of dating meteorite impacts where fine-grained melt rocks are often all that can be isotopically dated, and constraining the absolute age of biostratigraphic boundaries, which can only be constrained by age extrapolation. Further work is required to develop and improve the terrestrial impact age record and test whether or not the terrestrial impact flux increased significantly at certain times, perhaps resulting in major extinction events in Earth's biostratigraphic record.
  •  
43.
  • Seikrit, C, et al. (författare)
  • Biological responses to PDGF-AA versus PDGF-CC in renal fibroblasts
  • 2013
  • Ingår i: Nephrology, dialysis, transplantation : official publication of the European Dialysis and Transplant Association - European Renal Association. - : Oxford University Press (OUP). - 1460-2385. ; 28:4, s. 889-900
  • Tidskriftsartikel (refereegranskat)
  •  
44.
  • Skuladottir, AT, et al. (författare)
  • A genome-wide meta-analysis identifies 50 genetic loci associated with carpal tunnel syndrome
  • 2022
  • Ingår i: Nature communications. - : Springer Science and Business Media LLC. - 2041-1723. ; 13:1, s. 1598-
  • Tidskriftsartikel (refereegranskat)abstract
    • Carpal tunnel syndrome (CTS) is the most common entrapment neuropathy and has a largely unknown underlying biology. In a genome-wide association study of CTS (48,843 cases and 1,190,837 controls), we found 53 sequence variants at 50 loci associated with the syndrome. The most significant association is with a missense variant (p.Glu366Lys) in SERPINA1 that protects against CTS (P = 2.9 × 10−24, OR = 0.76). Through various functional analyses, we conclude that at least 22 genes mediate CTS risk and highlight the role of 19 CTS variants in the biology of the extracellular matrix. We show that the genetic component to the risk is higher in bilateral/recurrent/persistent cases than nonrecurrent/nonpersistent cases. Anthropometric traits including height and BMI are genetically correlated with CTS, in addition to early hormonal-replacement therapy, osteoarthritis, and restlessness. Our findings suggest that the components of the extracellular matrix play a key role in the pathogenesis of CTS.
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45.
  • Tedersoo, Leho, et al. (författare)
  • Global patterns in endemicity and vulnerability of soil fungi.
  • 2022
  • Ingår i: Global change biology. - : Wiley. - 1365-2486 .- 1354-1013. ; 28:22, s. 6696-6710
  • Tidskriftsartikel (refereegranskat)abstract
    • Fungi are highly diverse organisms, which provide multiple ecosystem services. However, compared with charismatic animals and plants, the distribution patterns and conservation needs of fungi have been little explored. Here, we examined endemicity patterns, global change vulnerability and conservation priority areas for functional groups of soil fungi based on six global surveys using a high-resolution, long-read metabarcoding approach. We found that the endemicity of all fungi and most functional groups peaks in tropical habitats, including Amazonia, Yucatan, West-Central Africa, Sri Lanka, and New Caledonia, with a negligible island effect compared with plants and animals. We also found that fungi are predominantly vulnerable to drought, heat and land-cover change, particularly in dry tropical regions with high human population density. Fungal conservation areas of highest priority include herbaceous wetlands, tropical forests, and woodlands. We stress that more attention should be focused on the conservation of fungi, especially root symbiotic arbuscular mycorrhizal and ectomycorrhizal fungi in tropical regions as well as unicellular early-diverging groups and macrofungi in general. Given the low overlap between the endemicity of fungi and macroorganisms, but high conservation needs in both groups, detailed analyses on distribution and conservation requirements are warranted for other microorganisms and soil organisms.
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46.
  • Wethers, Clare, 1991, et al. (författare)
  • Double, double, toil, and trouble: The tails, bubbles, and knots of the local compact obscured nucleus galaxy NGC 4418
  • 2024
  • Ingår i: Astronomy and Astrophysics. - 0004-6361 .- 1432-0746. ; 683
  • Tidskriftsartikel (refereegranskat)abstract
    • Context. Compact obscured nuclei (CONs) are an extremely obscured (NH2>1025 cm-2) class of galaxy nuclei thought to exist in 20-40 per cent of nearby (ultra-)luminous infrared galaxies While they have been proposed to represent a key phase of the active galactic nucleus (AGN) feedback cycle, the nature of these CONs -what powers them, their dynamics, and their impact on the host galaxy -remains unknown. Aims. This work analyses the galaxy-scale optical properties of the local CON NGC 4418 (z=0.00727). The key aims of the study are to understand the impact of nuclear outflows on the host galaxy and infer the power source of its CON. Through the mapping of the galaxy spectra and kinematics, we seek to identify new structures in NGC 4418 to ultimately reveal more about the CON's history, its impact on the host, and, more generally, the role CONs play in galaxy evolution. Methods. We present new, targeted integral field unit observations of the galaxy with the Multi-Unit Spectroscopic Explorer (MUSE). For the first time, we mapped the ionised and neutral gas components of the galaxy, along with their dynamical structure, to reveal several previously unknown features of the galaxy. Results. We confirm the presence of a previously postulated, blueshifted outflow along the minor axis of NGC 4418. We find this outflow to be decelerating and, for the first time, show it to extend in both directions from the nucleus. We report the discovery of two further outflow structures: a redshifted southern outflow connected to a tail of ionised gas surrounding the galaxy and a blueshifted bubble to the north. In addition to these features, we find the [OIII] emission reveals the presence of knots across the galaxy, which are consistent with regions of the galaxy that have been photoionised by an AGN. Conclusions. We identify several new features in NGC 4418, including a bubble structure, a reddened outflow, and [OIII] knot structures throughout the galaxy. We additionally confirm the presence of a bilateral blueshifted outflow along the minor axis. Based on the properties of these features, we conclude that the CON in NGC 4418 is most likely powered by AGN activity.
  •  
47.
  • Aalto, Susanne, 1964, et al. (författare)
  • Detection of HCN, HCO+, and HNC in the Mrk 231 molecular outflow. Dense molecular gas in the AGN wind
  • 2012
  • Ingår i: Astronomy and Astrophysics. - : EDP Sciences. - 0004-6361 .- 1432-0746. ; 537, s. 44-51
  • Tidskriftsartikel (refereegranskat)abstract
    • We obtained high-resolution (1.''55 × 1.''28) observations of HCN, HCO+, HNC 1-0 and HC3N 10-9 of the ultraluminous galaxy (ULIRG) Mrk 231 with the IRAM Plateau de Bure Interferometer.Results: We detect luminous emission from HCN, HCO+ and HNC 1-0 in the QSO ULIRG Mrk 231. All three lines show broad line wings - which are particularly prominent for HCN. Velocities are found to be similar ( ≈ ± 750 km s-1) to those found for CO 1-0. This is the first time bright HCN, HCO+ and HNC emission has been detected in a large-scale galactic outflow. We find that both the blue- and red-shifted line wings are spatially extended by at least 0.''75 (>700 pc) in a north-south direction. The line wings are brighter (relative to the line center intensity) in HCN than in CO 1-0 and line ratios suggest that the molecular outflow consists of dense (n > 104 cm-3) and clumpy gas with a high HCN abundance X(HCN) > 10-8. These properties are consistent with the molecular gas being compressed and fragmented by shocks in the outflow. Alternatively, HCN is instead pumped by mid-IR continuum, but we propose that this effect is not strong for the spatially extended outflowing gas. In addition, we find that the rotation of the main disk, in east-west direction, is also evident in the HCN, HCO+ and HNC line emission. An unexpectedly bright HC3N 10-9 line is detected inside the central 400 pc of Mrk 231. This HC3N emission may emerge from a shielded, dust-enshrouded region within the inner 40-50 pc where the gas is heated to high temperatures (200-300 K) by the AGN.
  •  
48.
  • Aalto, Susanne, 1964, et al. (författare)
  • High resolution observations of HCN and HCO+J = 3–2 in the disk and outflow of Mrk 231 -- Detection of vibrationally excited HCN in the warped nucleus
  • 2015
  • Ingår i: Astronomy and Astrophysics. - : EDP Sciences. - 0004-6361 .- 1432-0746. ; 574, s. 85-
  • Tidskriftsartikel (refereegranskat)abstract
    • Aims. Our goal is to study molecular gas properties in nuclei and large scale outflows/winds from active galactic nuclei (AGNs) and starburst galaxies.Methods. We obtained high resolution (0.̋25 to 0.̋90) observations of HCN and HCO+J = 3 → 2 of the ultraluminous QSO galaxy Mrk 231 with the IRAM Plateau de Bure Interferometer (PdBI).Results. We find luminous HCN and HCO+J = 3 → 2 emission in the main disk and we detect compact (r ≲ 0''̣1 (90 pc)) vibrationally excited HCN J = 3 → 2ν2 = 1f emission centred on the nucleus. The velocity field of the vibrationally excited HCN is strongly inclined (position angle PA = 155°) compared to the east-west rotation of the main disk. The nuclear (r ≲ 0.̋1) molecular mass is estimated to 8 × 108 M⊙ with an average N(H2) of 1.2 × 1024 cm-2. Prominent, spatially extended (≳350 pc) line wings are found for HCN J = 3 → 2 with velocities up to ± 750 km s-1. Line ratios indicate that the emission is emerging in dense gas n = 104−5 × 105 cm-3 of elevated HCN abundance X(HCN) = 10-8−10-6. The highest X(HCN) also allows for the emission to originate in gas of more moderate density. We tentatively detect nuclear emission from the reactive ion HOC+ with HCO+/HOC+ = 10−20.Conclusions. The HCN ν2 = 1f line emission is consistent with the notion of a hot, dusty, warped inner disk of Mrk 231 where the ν2 = 1f line is excited by bright mid-IR 14 μm continuum. We estimate the vibrational temperature Tvib to 200−400 K. Based on relative source sizes we propose that 50% of the main HCN emission may have its excitation affected by the radiation field through IR pumping of the vibrational ground state. The HCN emission in the line wings, however, is more extended and thus likely not strongly affected by IR pumping. Our results reveal that dense clouds survive (and/or are formed) in the AGN outflow on scales of at least several hundred pc before evaporating or collapsing. The elevated HCN abundance in the outflow is consistent with warm chemistry possibly related to shocks and/or X-ray irradiated gas. An upper limit to the mass and momentum flux is 4 × 108 M⊙ and 12LAGN/c, respectively, and we discuss possible driving mechanisms for the dense outflow.
  •  
49.
  • Aalto, Susanne, 1964, et al. (författare)
  • Probing highly obscured, self-absorbed galaxy nuclei with vibrationally excited HCN
  • 2015
  • Ingår i: Astronomy and Astrophysics. - : EDP Sciences. - 0004-6361 .- 1432-0746. ; 584
  • Tidskriftsartikel (refereegranskat)abstract
    • We present high resolution (0.'' 4) IRAM PdBI and ALMA mm and submm observations of the (ultra) luminous infrared galaxies ((U)LIRGs) IRAS 17208-0014, Arp220, IC 860 and Zw049.057 that reveal intense line emission from vibrationally excited (nu(2) = 1) J = 3-2 and 4-3 HCN. The emission is emerging from buried, compact (r 5 x 10(13) L-circle dot kpc(-2). These nuclei are likely powered by accreting supermassive black holes (SMBHs) and/or hot (>200 K) extreme starbursts. Vibrational, nu(2) = 1, lines of HCN are excited by intense 14 mu m mid-infrared emission and are excellent probes of the dynamics, masses, and physical conditions of (U)LIRG nuclei when H-2 column densities exceed 10(24) cm(-2). It is clear that these lines open up a new interesting avenue to gain access to the most obscured AGNs and starbursts. Vibrationally excited HCN acts as a proxy for the absorbed mid-infrared emission from the embedded nuclei, which allows for reconstruction of the intrinsic, hotter dust SED. In contrast, we show strong evidence that the ground vibrational state (. = 0), J = 3-2 and 4-3 rotational lines of HCN and HCO+ fail to probe the highly enshrouded, compact nuclear regions owing to strong self-and continuum absorption. The HCN and HCO+ line profiles are double-peaked because of the absorption and show evidence of non-circular motions-possibly in the form of in-or outflows. Detections of vibrationally excited HCN in external galaxies are so far limited to ULIRGs and early-type spiral LIRGs, and we discuss possible causes for this. We tentatively suggest that the peak of vibrationally excited HCN emission is connected to a rapid stage of nuclear growth, before the phase of strong feedback.
  •  
50.
  • Aalto, Susanne, 1964, et al. (författare)
  • The hidden heart of the luminous infrared galaxy IC 860: I. A molecular inflow feeding opaque, extreme nuclear activity
  • 2019
  • Ingår i: Astronomy and Astrophysics. - : EDP Sciences. - 0004-6361 .- 1432-0746. ; 627
  • Tidskriftsartikel (refereegranskat)abstract
    • High-resolution (0.'03-0.'09 (9-26 pc)) ALMA (100-350 GHz (λ3 to 0.8 mm)) and (0.'04 (11 pc)) VLA 45 GHz measurements have been used to image continuum and spectral line emission from the inner (100 pc) region of the nearby infrared luminous galaxy IC 860. We detect compact (r ∼ 10 pc), luminous, 3 to 0.8 mm continuum emission in the core of IC 860, with brightness temperatures TB > 160 K. The 45 GHz continuum is equally compact but significantly fainter in flux. We suggest that the 3 to 0.8 mm continuum emerges from hot dust with radius r ∼ 8 pc and temperature Td ∼ 280 K, and that it is opaque at millimetre wavelengths, implying a very large H2 column density N(H2)≥ 1026 cm-2. Vibrationally excited lines of HCN v2 = 1f J = 4 - 3 and 3-2 (HCN-VIB) are seen in emission and spatially resolved on scales of 40-50 pc. The line-to-continuum ratio drops towards the inner r = 4 pc, resulting in a ring-like morphology. This may be due to high opacities and matching HCN-VIB excitation- and continuum temperatures. The HCN-VIB emission reveals a north-south nuclear velocity gradient with projected rotation velocities of v = 100 km s-1 at r = 10 pc. The brightest emission is oriented perpendicular to the velocity gradient, with a peak HCN-VIB 3-2 TB of 115 K (above the continuum). Vibrational ground-state lines of HCN 3-2 and 4-3, HC15N 4-3, HCO+ 3-2 and 4-3, and CS 7-6 show complex line absorption and emission features towards the dusty nucleus. Redshifted, reversed P-Cygni profiles are seen for HCN and HCO+ consistent with gas inflow with vin ≤ 50 km s-1. Foreground absorption structures outline the flow, and can be traced from the north-east into the nucleus. In contrast, CS 7-6 has blueshifted line profiles with line wings extending out to -180 km s-1. We suggest that a dense and slow outflow is hidden behind a foreground layer of obscuring, inflowing gas. The centre of IC 860 is in a phase of rapid evolution where an inflow is building up a massive nuclear column density of gas and dust that feeds star formation and/or AGN activity. The slow, dense outflow may be signaling the onset of feedback. The inner, r = 10 pc, IR luminosity may be powered by an AGN or a compact starburst, which then would likely require a top-heavy initial mass function.
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