| 1. |
- Fomalont, E. B., et al.
(författare)
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THE 2014 ALMA LONG BASELINE CAMPAIGN: AN OVERVIEW
- 2015
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Ingår i: Astrophysical Journal Letters. - : American Astronomical Society. - 2041-8213 .- 2041-8205. ; 808:1
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Tidskriftsartikel (refereegranskat)abstract
- A major goal of the Atacama Large Millimeter/submillimeter Array (ALMA) is to make accurate images with resolutions of tens of milliarcseconds, which at submillimeter (submm) wavelengths requires baselines up to similar to 15 km. To develop and test this capability, a Long Baseline Campaign (LBC) was carried out from 2014 September to late November, culminating in end-to-end observations, calibrations, and imaging of selected Science Verification (SV) targets. This paper presents an overview of the campaign and its main results, including an investigation of the short-term coherence properties and systematic phase errors over the long baselines at the ALMA site, a summary of the SV targets and observations, and recommendations for science observing strategies at long baselines. Deep ALMA images of the quasar 3C 138 at 97 and 241 GHz are also compared to VLA 43 GHz results, demonstrating an agreement at a level of a few percent. As a result of the extensive program of LBC testing, the highly successful SV imaging at long baselines achieved angular resolutions as fine as 19 mas at similar to 350 GHz. Observing with ALMA on baselines of up to 15 km is now possible, and opens up new parameter space for submm astronomy.
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| 2. |
- Braine, J., et al.
(författare)
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Cool gas and dust in M33: Results from the HERschel M33 Extended Survey (HERM33ES)
- 2010
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Ingår i: Astronomy and Astrophysics. - : EDP Sciences. - 0004-6361 .- 1432-0746. ; 518:Article Number: L69
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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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| 3. |
- Kramer, C., et al.
(författare)
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PACS and SPIRE photometer maps of M33: First results of the HERschel M33 Extended Survey (HERM33ES)
- 2010
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Ingår i: Astronomy and Astrophysics. - : EDP Sciences. - 0004-6361 .- 1432-0746. ; 518:Article Number: L67
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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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| 4. |
- Abend, Sven, et al.
(författare)
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Terrestrial very-long-baseline atom interferometry : Workshop summary
- 2024
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Ingår i: AVS Quantum Science. - : American Institute of Physics (AIP). - 2639-0213. ; 6:2
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Forskningsöversikt (refereegranskat)abstract
- This document presents a summary of the 2023 Terrestrial Very-Long-Baseline Atom Interferometry Workshop hosted by CERN. The workshop brought together experts from around the world to discuss the exciting developments in large-scale atom interferometer (AI) prototypes and their potential for detecting ultralight dark matter and gravitational waves. The primary objective of the workshop was to lay the groundwork for an international TVLBAI proto-collaboration. This collaboration aims to unite researchers from different institutions to strategize and secure funding for terrestrial large-scale AI projects. The ultimate goal is to create a roadmap detailing the design and technology choices for one or more kilometer--scale detectors, which will be operational in the mid-2030s. The key sections of this report present the physics case and technical challenges, together with a comprehensive overview of the discussions at the workshop together with the main conclusions.
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| 5. |
- Andreani, P., et al.
(författare)
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The European ALMA Regional Centre: a model of user support
- 2014
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Ingår i: Proceedings of SPIE - The International Society for Optical Engineering. - : SPIE. - 0277-786X .- 1996-756X. - 9780819496171 ; 9149, s. Art. no. 91490Y-
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Konferensbidrag (refereegranskat)abstract
- The ALMA Regional Centres (ARCs) form the interface between the ALMA observatory and the user community from the proposal preparation stage to the delivery of data and their subsequent analysis. The ARCs provide critical services to both the ALMA operations in Chile and to the user community. These services were split by the ALMA project into core and additional services. The core services are financed by the ALMA operations budget and are critical to the successful operation of ALMA. They are contractual obligations and must be delivered to the ALMA project. The additional services are not funded by the ALMA project and are not contractual obligations, but are critical to achieve ALMA full scientific potential. A distributed network of ARC nodes (with ESO being the central ARC) has been set up throughout Europe at the following seven locations: Bologna, Bonn-Cologne, Grenoble, Leiden, Manchester, Ondrejov, Onsala. These ARC nodes are working together with the central node at ESO and provide both core and additional services to the ALMA user community. This paper presents the European ARC, and how it operates in Europe to support the ALMA community. This model, although complex in nature, is turning into a very successful one, providing a service to the scientific community that has been so far highly appreciated. The ARC could become a reference support model in an age where very large collaborations are required to build large facilities, and support is needed for geographically and culturally diverse communities.
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| 6. |
- Basu, K., et al.
(författare)
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Non-parametric modeling of the intra-cluster gas using APEX-SZ bolometer imaging data
- 2010
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Ingår i: Astronomy and Astrophysics. - : EDP Sciences. - 0004-6361 .- 1432-0746. ; 519:Article Number: A29
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Tidskriftsartikel (refereegranskat)abstract
- Aims. We aim to demonstrate the usability of mm-wavelength imaging data obtained from the APEX-SZ bolometer array to derive the radial temperature profile of the hot intra-cluster gas out to radius r(500) and beyond. The goal is to study the physical properties of the intra-cluster gas by using a non-parametric de-projection method that is, aside from the assumption of spherical symmetry, free from modeling bias. Methods. We use publicly available X-ray spectroscopic-imaging data in the 0.7-2 keV energy band from the XMM-Newton observatory and our Sunyaev-Zel'dovich Effect (SZE) imaging data from the APEX-SZ experiment at 150 GHz to de-project the density and temperature profiles for a well-studied relaxed cluster, Abell 2204. We derive the gas density, temperature and entropy profiles assuming spherical symmetry, and obtain the total mass profile under the assumption of hydrostatic equilibrium. For comparison with X-ray spectroscopic temperature models, a re-analysis of recent Chandra observation is done with the latest calibration updates. We compare the results with that from an unrelaxed cluster, Abell 2163, to illustrate some differences between relaxed and merging systems. Results. Using the non-parametric modeling, we demonstrate a decrease of gas temperature in the cluster outskirts, and also measure gas entropy profiles, both of which are done for the first time independently of X-ray spectroscopy using the SZE and X-ray imaging data. The gas entropy measurement in the central 100 kpc shows the usability of APEX-SZ data for inferring cluster dynamical states with this method. The contribution of the SZE systematic uncertainties in measuring T-e at large radii is shown to be small compared to XMM-Newton and Chandra systematic spectroscopic errors. The total mass profile obtained using the hydrostatic equilibrium assumption is in agreement with the published X-ray and weak lensing results; the upper limit on M-200 derived from the non-parametric method is consistent with the NFW model prediction from weak lensing analysis.
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| 7. |
- Coppin, K. E. K., et al.
(författare)
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Herschel-PACS observations of [O I]63 μm towards submillimetre galaxies at z~1
- 2012
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Ingår i: Monthly Notices of the Royal Astronomical Society. - : Oxford University Press (OUP). - 0035-8711 .- 1365-2966. ; 427:1, s. 520-532
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Tidskriftsartikel (refereegranskat)abstract
- We present Herschel-PACS spectroscopy of the [O I]63 μm far-infrared cooling line from a sample of six unlensed and spectroscopically confirmed 870 μm selected submillimetre (submm) galaxies (SMGs) at 1.1
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| 8. |
- Schwan, D., et al.
(författare)
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Invited Article: Millimeter-wave bolometer array receiver for the Atacama pathfinder experiment Sunyaev-Zel'dovich (APEX-SZ) instrument
- 2011
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Ingår i: Review of Scientific Instruments. - : AIP Publishing. - 1089-7623 .- 0034-6748. ; 82:9
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Tidskriftsartikel (refereegranskat)abstract
- The Atacama pathfinder experiment Sunyaev-Zel'dovich (APEX-SZ) instrument is a millimeter-wave cryogenic receiver designed to observe galaxy clusters via the Sunyaev-Zel'dovich effect from the 12 m APEX telescope on the Atacama plateau in Chile. The receiver contains a focal plane of 280 superconducting transition-edge sensor (TES) bolometers instrumented with a frequency-domain multiplexed readout system. The bolometers are cooled to 280 mK via a three-stage helium sorption refrigerator and a mechanical pulse-tube cooler. Three warm mirrors, two 4 K lenses, and a horn array couple the TES bolometers to the telescope. APEX-SZ observes in a single frequency band at 150 GHz with 1' angular resolution and a 22' field-of-view, all well suited for cluster mapping. The APEX-SZ receiver has played a key role in the introduction of several new technologies including TES bolometers, the frequency-domain multiplexed readout, and the use of a pulse-tube cooler with bolometers. As a result of these new technologies, the instrument has a higher instantaneous sensitivity and covers a larger field-of-view than earlier generations of Sunyaev-Zel'dovich instruments. The TES bolometers have a median sensitivity of 890 mu K(CMB)root s (NEy of 3.5 x 10(-4) root s). We have also demonstrated upgraded detectors with improved sensitivity of 530 mu K(CMB) root s (NEy of 2.2 x 10(-4) root s). Since its commissioning in April 2007, APEX-SZ has been used to map 48 clusters. We describe the design of the receiver and its performance when installed on the APEX telescope.
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| 9. |
- Bender, A. N., et al.
(författare)
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Galaxy cluster scaling relations measured with APEX-SZ
- 2016
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Ingår i: Monthly Notices of the Royal Astronomical Society. - : Oxford University Press (OUP). - 0035-8711 .- 1365-2966. ; 460:4, s. 3432-3446
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Tidskriftsartikel (refereegranskat)abstract
- We present thermal Sunyaev-Zel'dovich effect (SZE) measurements for 42 galaxy clusters observed at 150 GHz with the APEX-SZ experiment. For each cluster, we model the pressure profile and calculate the integrated Comptonization Y to estimate the total thermal energy of the intraclustermedium (ICM). We compare the measured Y values to X-ray observables of the ICM from the literature (cluster gas mass M-gas, temperature T-X, and Y-X = MgasTX) that relate to total cluster mass. We measure power-law scaling relations, including an intrinsic scatter, between the SZE and X-ray observables for three subsamples within the set of 42 clusters that have uniform X-ray analysis in the literature. We observe that differences between these X-ray analyses introduce significant variance into the measured scaling relations, particularly affecting the normalization. For all three subsamples, we find results consistent with a selfsimilarmodel of cluster evolution dominated by gravitational effects. Comparing to predictions from numerical simulations, these scaling relations prefer models that include cooling and feedback in the ICM. Lastly, we measure an intrinsic scatter of similar to 28 per cent in the Y - Y-X scaling relation for all three subsamples.
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| 10. |
- Chen, C. C., et al.
(författare)
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A Spatially Resolved Study of Cold Dust, Molecular Gas, H II Regions, and Stars in the z = 2.12 Submillimeter Galaxy ALESS67.1
- 2017
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Ingår i: Astrophysical Journal. - : American Astronomical Society. - 1538-4357 .- 0004-637X. ; 846:2
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Tidskriftsartikel (refereegranskat)abstract
- We present detailed studies of a z = 2.12 submillimeter galaxy, ALESS67.1, using sub-arcsecond resolution ALMA, adaptive optics-aided VLT/SINFONI, and Hubble Space Telescope (HST)/CANDELS data to investigate the kinematics and spatial distributions of dust emission (870 ?m continuum), 12CO(J = 3-2), strong optical emission lines, and visible stars. Dynamical modeling of the optical emission lines suggests that ALESS67.1 is not a pure rotating disk but a merger, consistent with the apparent tidal features revealed in the HST imaging. Our sub-arcsecond resolution data set allows us to measure half-light radii for all the tracers, and we find a factor of 4-6 smaller sizes in dust continuum compared to all the other tracers, including 12CO; also, ultraviolet (UV) and H? emission are significantly offset from the dust continuum. The spatial mismatch between the UV continuum and the cold dust and gas reservoir supports the explanation that geometrical effects are responsible for the offset of the dusty galaxy on the IRX-? diagram. Using a dynamical method we derive an , consistent with other submillimeter galaxies (SMGs) that also have resolved CO and dust measurements. Assuming a single value we also derive resolved gas and star formation rate surface densities, and find that the core region of the galaxy ( kpc) follows the trend of mergers on the Schmidt-Kennicutt relationship, whereas the outskirts ( kpc) lie on the locus of normal star-forming galaxies, suggesting different star formation efficiencies within one galaxy. Our results caution against using single size or morphology for different tracers of the star formation activity and gas content of galaxies, and therefore argue the need to use spatially resolved, multi-wavelength observations to interpret the properties of SMGs, and perhaps even for galaxies in general.
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| 11. |
- Hodge, J. A., et al.
(författare)
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An ALMA Survey of Submillimeter Galaxies in the Extended Chandra Deep Field South: Source Catalog and Multiplicity
- 2013
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Ingår i: Astrophysical Journal. - 1538-4357 .- 0004-637X. ; 768:1
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Tidskriftsartikel (refereegranskat)abstract
- We present an Atacama Large Millimeter/submillimeter Array (ALMA) Cycle 0 survey of 126 submillimeter sources from the LABOCA ECDFS Submillimeter Survey (LESS). Our 870 mu m survey with ALMA (ALESS) has produced maps similar to 3x deeper and with a beam area similar to 200x smaller than the original LESS observations, doubling the current number of interferometrically-observed submillimeter sources. The high resolution of these maps allows us to resolve sources that were previously blended and accurately identify the origin of the submillimeter emission. We discuss the creation of the ALESS submillimeter galaxy (SMG) catalog, including the main sample of 99 SMGs and a supplementary sample of 32 SMGs. We find that at least 35% (possibly up to 50%) of the detected LABOCA sources have been resolved into multiple SMGs, and that the average number of SMGs per LESS source increases with LESS flux density. Using the (now precisely known) SMG positions, we empirically test the theoretical expectation for the uncertainty in the single-dish source positions. We also compare our catalog to the previously predicted radio/mid-infrared counterparts, finding that 45% of the ALESS SMGs were missed by this method. Our similar to 1 ''.6 resolution allows us to measure a size of similar to 9 kpc x 5 kpc for the rest-frame similar to 300 mu m emission region in one resolved SMG, implying a star formation rate surface density of 80 M-circle dot yr(-1) kpc(-2), and we constrain the emission regions in the remaining SMGs to be
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| 12. |
- Hodge, J. A., et al.
(författare)
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Kiloparsec-Scale Dust Disks in High-Redshift Luminous Submillimeter Galaxies
- 2016
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Ingår i: Astrophysical Journal. - : American Astronomical Society. - 1538-4357 .- 0004-637X. ; 833:1
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Tidskriftsartikel (refereegranskat)abstract
- We present high-resolution (0 ''.6) 870 mu m Atacama Large Millimeter/submillimeter Array (ALMA) imaging of 16 luminous (LIR similar to 4 x 10(12) L-circle dot) submillimeter galaxies (SMGs) from the ALESS survey of the Extended Chandra Deep Field South. This dust imaging traces the dust-obscured star formation in these z similar to 2.5 galaxies on similar to 1.3 kpc scales. The emission has a median effective radius of R-e = 0 ''.24 +/- 0 ''.02, corresponding to a typical physical size of R-e= 1.8 +/- 0.2 kpc. We derive a median Sersic index of n = 0.9 +/- 0.2, implying that the dust emission is remarkably disk-like at the current resolution and sensitivity. We use different weighting schemes with the visibilities to search for clumps on 0 ''.12. (similar to 1.0 kpc) scales, but we find no significant evidence for clumping in the majority of cases. Indeed, we demonstrate using simulations that the observed morphologies are generally consistent with smooth exponential disks, suggesting that caution should be exercised when identifying candidate clumps in even moderate signal-to-noise ratio interferometric data. We compare our maps to comparable-resolution Hubble Space Telescope H-160-band images, finding that the stellar morphologies appear significantly more extended and disturbed, and suggesting that major mergers may be responsible for driving the formation of the compact dust disks we observe. The stark contrast between the obscured and unobscured morphologies may also have implications for SED fitting routines that assume the dust is co-located with the optical/near-IR continuum emission. Finally, we discuss the potential of the current bursts of star formation to transform the observed galaxy sizes and light profiles, showing that the z similar to 0 descendants of these SMGs are expected to have stellar masses, effective radii, and gas surface densities consistent with the most compact massive (M* similar to 1-2 x 10(11) M-circle dot) early-type galaxies observed locally.
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| 13. |
- Johansson, Daniel, 1980, et al.
(författare)
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Molecular gas and dust in the highly magnified z similar to 2.8 galaxy behind the Bullet Cluster
- 2012
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Ingår i: Astronomy and Astrophysics. - : EDP Sciences. - 0004-6361 .- 1432-0746. ; 543, s. Article Number: A62 (pp. 1-10)
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Tidskriftsartikel (refereegranskat)abstract
- Context. The gravitational magnification provided by massive galaxy clusters makes it possible to probe the physical conditions in distant galaxies that are of lower luminosity than those in blank fields and likely more representative of the bulk of the high-redshift galaxy population. Aims. We aim to constrain the basic properties of molecular gas in a strongly magnified submm galaxy located behind the massive Bullet Cluster (1E 0657-56). This galaxy (SMM J0658) is split into three images, with a total magnification factor of almost 100. Methods. We used the Australia Telescope Compact Array (ATCA) to search for (CO)-C-12(1-0) and (CO)-C-12(3-2) line emission from SMM J0658. We also used the SABOCA bolometer camera on the Atacama Pathfinder EXperiment (APEX) telescope to measure the continuum emission at 350 mu m. Results. CO(1-0) and CO(3-2) are detected at 6.8 sigma and 7.5 sigma significance when the spectra toward the two brightest images of the galaxy are combined. From the CO(1-0) luminosity we derive a mass of cold molecular gas of (1.8 +/- 0.3) x 10(9) M-circle dot, using the CO to H-2 conversion factor commonly used for luminous infrared galaxies. This is 45 +/- 25% of the stellar mass. From the width of the CO lines we derive a dynamical mass within the CO-emitting region L of (1.3 +/- 0.4) x 10(10)(L/1 kpc) M-circle dot. We refine the redshift determination of SMM J0658 to z = 2.7793 +/- 0.0003. The CO(3-2) to CO(1-0) brightness temperature ratio is 0.56(-0.15)(+0.21), which is similar to the values found in other star-forming galaxies. Continuum emission at 350 mu m from SMM J0658 was detected with SABOCA at a signal-to-noise ratio of 3.6. The flux density is consistent with previous measurements at the same wavelength by the Herschel satellite and BLAST balloon-borne telescope. We study the spectral energy distribution of SMM J0658 and derive a dust temperature of 33 +/- 5 K and a dust mass of 1.1(-0.3)(+0.8) x 10(7) M-circle dot. Conclusions. SMM J0658 is one of the least massive submm galaxies discovered so far. As a likely representative of the bulk of the submm galaxy population, it is a prime target for future observations.
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| 14. |
- Karim, A., et al.
(författare)
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An ALMA survey of submillimetre galaxies in the Extended Chandra Deep Field South: high-resolution 870 mu m source counts
- 2013
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Ingår i: Monthly Notices of the Royal Astronomical Society. - : Oxford University Press (OUP). - 0035-8711 .- 1365-2966. ; 432:1, s. 2-9
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Tidskriftsartikel (refereegranskat)abstract
- We report the first counts of faint submillimetre galaxies (SMGs) in the 870-mu m band derived from arcsecond-resolution observations with the Atacama Large Millimeter Array (ALMA). We have used ALMA to map a sample of 122 870-mu m-selected submillimetre sources drawn from the 0 degrees.5x0 degrees.5 the Large Apex BOlometer CAmera (LABOCA) Extended Chandra Deep Field South submillimetre survey (LESS). These ALMA maps have an average depth of sigma 870(mu m) similar to 0.4 mJy, some approximately three times deeper than the original LABOCA survey and critically the angular resolution is more than an order of magnitude higher, FWHM of similar to 1.5 arcsec compared to similar to 19 arcsec for the LABOCA discovery map. This combination of sensitivity and resolution allows us to precisely pinpoint the SMGs contributing to the submillimetre sources from the LABOCA map, free from the effects of confusion. We show that our ALMA-derived SMG counts broadly agree with the submillimetre source counts from previous, lower resolution single-dish surveys, demonstrating that the bulk of the submillimetre sources are not caused by blending of unresolved SMGs. The difficulty which well-constrained theoretical models have in reproducing the high surface densities of SMGs, thus remains. However, our observations do show that all of the very brightest sources in the LESS sample, S-870 (mu m) greater than or similar to 12 mJy, comprise emission from multiple, fainter SMGs, each with 870-mu m fluxes of less than or similar to 9 mJy. This implies a natural limit to the star formation rate in SMGs of less than or similar to 10(3) M-circle dot yr(-1), which in turn suggests that the space densities of z > 1 galaxies with gas masses in excess of similar to 5 x 10(10) M-circle dot is
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| 15. |
- Nagarajan, A., et al.
(författare)
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Weak-lensing mass calibration of the Sunyaev-Zel'dovich effect using APEX-SZ galaxy clusters
- 2019
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Ingår i: Monthly Notices of the Royal Astronomical Society. - : Oxford University Press (OUP). - 0035-8711 .- 1365-2966. ; 488:2, s. 1728-1759
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Tidskriftsartikel (refereegranskat)abstract
- The use of galaxy clusters as precision cosmological probes relies on an accurate determination of their masses. However, inferring the relationship between cluster mass and observables from direct observations is difficult and prone to sample selection biases. In this work, we use weak lensing as the best possible proxy for cluster mass to calibrate the Sunyaev-Zel'dovich (SZ) effect measurements from the APEX-SZ experiment. For a well-defined (ROSAT) X-ray complete cluster sample, we calibrate the integrated Comptonization parameter, Y-SZ, to the weak-lensing derived total cluster mass, M-500. We employ a novel Bayesian approach to account for the selection effects by jointly fitting both the SZ Comptonization, Y-SZ-M-500, and the X-ray luminosity, Lx-M-500, scaling relations. We also account for a possible correlation between the intrinsic (lognormal) scatter of L-x and Y-SZ at fixed mass. We find the corresponding correlation coefficient to be r = 0.47(-0.35)(+0.24), and at the current precision level our constraints on the scaling relations are consistent with previous works. For our APEX-SZ sample, we find that ignoring the covariance between the SZ and X-ray observables biases the normalization of the Y-SZ-M-500 scaling high by 1-2 sigma and the slope low by similar to 1 sigma, even when the SZ effect plays no role in the sample selection. We conclude that for higher precision data and larger cluster samples, as anticipated from on-going and near-future cluster cosmology experiments, similar biases (due to intrinsic covariances of cluster observables) in the scaling relations will dominate the cosmological error budget if not accounted for correctly.
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| 16. |
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| 17. |
- Schwan, D., et al.
(författare)
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APEX-SZ: The Atacama Pathfinder EXperiment Sunyaev-Zel'dovich Instrument
- 2012
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Ingår i: The Messenger. ; 147, s. 7-12
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- The APEX–SZ instrument was a millimetre-wave (150 GHz) cryogenic receiverfor the APEX telescope designedto observe galaxy clusters via theSunyaev–Zel’dovich Effect (SZE). Thereceiver contained a focal plane of280 superconducting transition-edgesensor bolometers equipped with afrequency-domain-multiplexed readoutsystem, and it played a key role in theintroduction of these new, robust, andscalable technologies. With 1-arcminuteresolution, the instrument had a higherinstantaneous sensitivity and covered alarger field of view (22 arcminutes) thanearlier generations of SZE instruments.During its period of operation from 2007to 2010, APEX–SZ was used to imageover 40 clusters and map fields overlappingwith external datasets. This paperbriefly describes the instrument anddata reduction procedure and presentsa cluster image gallery, as well as resultsfor the Bullet cluster, Abell 2204, Abell2163, and a power spectrum analysis inthe XMM-LSS field.
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| 18. |
- Simpson, J. M., et al.
(författare)
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AN ALMA SURVEY OF SUBMILLIMETER GALAXIES IN THE EXTENDED CHANDRA DEEP FIELD SOUTH: THE REDSHIFT DISTRIBUTION AND EVOLUTION OF SUBMILLIMETER GALAXIES
- 2014
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Ingår i: Astrophysical Journal. - : American Astronomical Society. - 1538-4357 .- 0004-637X. ; 788:2
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Tidskriftsartikel (refereegranskat)abstract
- We present the first photometric redshift distribution for a large sample of 870 mu m submillimeter galaxies (SMGs) with robust identifications based on observations with ALMA. In our analysis we consider 96 SMGs in the Extended Chandra Deep Field South, 77 of which have 4-19 band photometry. We model the SEDs for these 77 SMGs, deriving a median photometric redshift of z(phot) = 2.3 +/- 0.1. The remaining 19 SMGs have insufficient photometry to derive photometric redshifts, but a stacking analysis of Herschel observations confirms they are not spurious. Assuming that these SMGs have an absolute H-band magnitude distribution comparable to that of a complete sample of z similar to 1-2 SMGs, we demonstrate that they lie at slightly higher redshifts, raising the median redshift for SMGs to zphot = 2.5 +/- 0.2. Critically we show that the proportion of galaxies undergoing an SMG-like phase at z >= 3 is at most 35% +/- 5% of the total population. We derive a median stellar mass of M star = (8 +/- 1) x 10(10) M circle dot, although there are systematic uncertainties of up to 5 x for individual sources. Assuming that the star formation activity in SMGs has a timescale of similar to 100 Myr, we show that their descendants at z similar to 0 would have a space density and MH distribution that are in good agreement with those of local ellipticals. In addition, the inferred mass-weighted ages of the local ellipticals broadly agree with the look-back times of the SMG events. Taken together, these results are consistent with a simple model that identifies SMGs as events that form most of the stars seen in the majority of luminous elliptical galaxies at the present day.
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| 19. |
- Steg, Linda, et al.
(författare)
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A method to identify barriers to and enablers of implementing climate change mitigation options
- 2022
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Ingår i: One Earth. - : Elsevier BV. - 2590-3330 .- 2590-3322. ; 5:11, s. 1216-1227
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Forskningsöversikt (refereegranskat)abstract
- Mitigation option are not yet being implemented at the scale required to limit global warming to well below 2°C. Various factors have been identified that inhibit the implementation of specific mitigation options. Yet, an integrated assessment of key barriers and enablers is lacking. Here we present a comprehensive framework to assess which factors inhibit and enable the implementation of mitigation options. The framework comprises six dimensions, each encompassing different criteria: geophysical, environmental-ecological, technological, economic, sociocultural, and institutional feasibility. We demonstrate the approach by assessing to what extent each criterion and dimension affects the feasibility of six mitigation options. The assessment reveals that institutional factors inhibit the implementation of many options that need to be addressed to increase their feasibility. Of all the options assessed, many factors enable the implementation of solar energy, while only a few barriers would need to be addressed to implement solar energy at scale.
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| 20. |
- Swinbank, A. M., et al.
(författare)
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An ALMA survey of submillimetre galaxies in the Extended Chandra Deep Field-South: detection of C II at z=4.4
- 2012
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Ingår i: Monthly Notices of the Royal Astronomical Society. - : Oxford University Press (OUP). - 0035-8711 .- 1365-2966. ; 427:2, s. 1066-1074
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Tidskriftsartikel (refereegranskat)abstract
- We present Atacama Large Millimeter Array (ALMA) 870-mu m (345-GHz) observations of two submillimetre galaxies (SMGs) drawn from an ALMA study of the 126 submillimetre sources from the LABOCA Extended Chandra Deep Field-South Survey (LESS). The ALMA data identify the counterparts to these previously unidentified submillimetre sources and serendipitously detect bright emission lines in their spectra which we show are most likely to be [CII] 157.74 mu m emission yielding redshifts of z = 4.42 and 4.44. This blind detection rate within the 7.5-GHz bandpass of ALMA is consistent with the previously derived photometric redshift distribution of SMGs and suggests a modest, but not dominant (less than or similar to 25 per cent), tail of 870-mu m selected SMGs at z greater than or similar to 4. We find that the ratio of L-[CII]/L-FIR in these SMGs is much higher than seen for similarly far-infrared-luminous galaxies at z similar to 0, which is attributed to the more extended gas reservoirs in these high-redshift ultraluminous infrared galaxies (ULIRGs). Indeed, in one system we show that the [C II] emission shows hints of extended emission on greater than or similar to 3 kpc scales. Finally, we use the volume probed by our ALMA survey to show that the bright end of the [CII] luminosity function evolves strongly between z = 0 and similar to 4.4, reflecting the increased interstellar medium cooling in galaxies as a result of their higher star formation rates. These observations demonstrate that even with short integrations, ALMA is able to detect the dominant fine-structure cooling lines from high-redshift ULIRGs, measure their energetics and spatially resolved properties and trace their evolution with redshift.
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| 21. |
- Wang, R., et al.
(författare)
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STAR FORMATION AND GAS KINEMATICS OF QUASAR HOST GALAXIES AT z similar to 6: NEW INSIGHTS FROM ALMA
- 2013
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Ingår i: Astrophysical Journal. - : American Astronomical Society. - 1538-4357 .- 0004-637X. ; 773:1
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Tidskriftsartikel (refereegranskat)abstract
- We present Atacama Large Millimeter/submillimeter Array (ALMA) observations of the [C Pi] 158 mu m fine structure line and dust continuum emission from the host galaxies of five redshift 6 quasars. We also report complementary observations of 250 GHz dust continuum and CO (6-5) line emission from the z = 6.00 quasar SDSS J231038.88+185519.7 using the IRAM facilities. The ALMA observations were carried out in the extended array at 0.'' 7 resolution. We have detected the line and dust continuum in all five objects. The derived [C Pi] line luminosities are 1.6 x 10(9) to 8.7 x 10(9) L-circle dot and the [C Pi]-to-FIR luminosity ratios are 2.9-5.1 x 10(-4), which is comparable to the values found in other high-redshift quasar-starburst systems and local ultra-luminous infrared galaxies. The sources are marginally resolved and the intrinsic source sizes (major axis FWHM) are constrained to be 0.'' 3-0.'' 6 (i.e., 1.7-3.5 kpc) for the [C Pi] line emission and 0.'' 2-0.'' 4 (i.e., 1.2-2.3 kpc) for the continuum. These measurements indicate that there is vigorous star formation over the central few kpc in the quasar host galaxies. The ALMA observations also constrain the dynamical properties of the star-forming gas in the nuclear region. The intensity-weighted velocity maps of three sources show clear velocity gradients. Such velocity gradients are consistent with a rotating, gravitationally bound gas component, although they are not uniquely interpreted as such. Under the simplifying assumption of rotation, the implied dynamical masses within the [C Pi]-emitting regions are of order 10(10)-10(11) M-circle dot. Given these estimates, the mass ratios between the supermassive black holes and the spheroidal bulge are an order of magnitude higher than the mean value found in local spheroidal galaxies, which is in agreement with results from previous CO observations of high redshift quasars.
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| 22. |
- Wardlow, J. L., et al.
(författare)
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The LABOCA survey of the Extended Chandra Deep Field-South: a photometric redshift survey of submillimetre galaxies
- 2011
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Ingår i: Monthly Notices of the Royal Astronomical Society. - : Oxford University Press (OUP). - 0035-8711 .- 1365-2966. ; 415:2, s. 1479-1508
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Tidskriftsartikel (refereegranskat)abstract
- We derive photometric redshifts from 17-band optical to mid-infrared photometry of 78 robust radio, 24-mu m and Spitzer IRAC counterparts to 72 of the 126 submillimetre galaxies (SMGs) selected at 870 mu m by LABOCA observations in the Extended Chandra Deep Field-South (ECDF-S). We test the photometric redshifts of the SMGs against the extensive archival spectroscopy in the ECDF-S. The median photometric redshift of identified SMGs is z = 2.2 +/- 0.1, the standard deviation is sigma(z) = 0.9 and we identify 11 (similar to 15 per cent) high-redshift (z >= 3) SMGs. A statistical analysis of sources in the error circles of unidentified SMGs identifies a population of possible counterparts with a redshift distribution peaking at z = 2.5 +/- 0.2, which likely comprises similar to 60 per cent of the unidentified SMGs. This confirms that the bulk of the undetected SMGs are coeval with those detected in the radio/mid-infrared. We conclude that at most similar to 15 per cent of all the SMGs are below the flux limits of our IRAC observations and thus may lie at z greater than or similar to 3 and hence at most similar to 30 per cent of all SMGs have z greater than or similar to 3. We estimate that the full S(870 mu m) > 4mJy SMG population has a median redshift of 2.5 +/- 0.5. In contrast to previous suggestions, we find no significant correlation between submillimetre flux and redshift. The median stellar mass of the SMGs derived from spectral energy distribution fitting is (9.1 +/- 0.5) x 10(10)M(circle dot) although we caution that the uncertainty in the star formation histories results in a factor of similar to 5 uncertainty in these stellarmasses. Using a single temperature modified blackbody fit with beta = 1.5, the median characteristic dust temperature of SMGs is 37.4 +/- 1.4K. The infrared luminosity function shows that SMGs at z = 2-3 typically have higher far-infrared luminosities and luminosity density than those at z = 1-2. This is mirrored in the evolution of the star formation rate density (SFRD) for SMGs which peaks at z similar to 2. The maximum contribution of bright SMGs to the global SFRD (similar to 5 per cent for SMGs with S(870 mu m) greater than or similar to 4mJy or similar to 50 per cent extrapolated to SMGs with S(870 mu m) > 1mJy) also occurs at z similar to 2.
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| 23. |
- Chan, Elizabeth S. M., et al.
(författare)
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Triarchic traits as risk versus protective factors for ADHD symptomatology : A prospective longitudinal investigation
- 2024
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Ingår i: Development and psychopathology (Print). - : Cambridge University Press. - 0954-5794 .- 1469-2198. ; , s. 1-12
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Tidskriftsartikel (refereegranskat)abstract
- Attention-deficit/hyperactivity disorder (ADHD) symptoms are associated with myriad adverse outcomes, including interpersonal difficulties, but factors that moderate the developmental course and functional impact of ADHD over time are not well understood. The present study evaluated developmental contributions of the triarchic neurobehavioral traits (boldness, meanness, and disinhibition) to ADHD symptomatology and its subdimensions from adolescence to young adulthood. Participants were twins and triplets assessed at ages 14, 17, and 19 (initial N = 1,185, 51.2% female). Path analyses using negative binomial regression revealed that boldness at age 14 was associated with more ADHD symptoms cross-sectionally (especially hyperactivity/impulsivity), but fewer symptoms (especially inattention) at age 19 in the prospective analysis. Notably, inclusion of interpersonal problems at ages 14 and 17 as covariates reduced the latter effect to nonsignificant. Disinhibition concurrently and prospectively predicted higher levels of ADHD symptoms, including both subdimensions, and the prospective effects were partially mediated by greater social impairment at age 17. Meanness prospectively (but not concurrently) predicted higher levels of hyperactivity/impulsivity symptoms. Sex moderated certain associations of meanness and disinhibition with ADHD symptoms. These findings highlight how fundamental neurobehavioral traits shape both psychopathology and adaptive outcomes in the developmental course of ADHD.
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| 24. |
- Johansson, Daniel, 1980, et al.
(författare)
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Submillimeter galaxies behind the Bullet cluster (1E 0657-56)
- 2010
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Ingår i: Astronomy and Astrophysics. - : EDP Sciences. - 0004-6361 .- 1432-0746. ; 514:12
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Tidskriftsartikel (refereegranskat)abstract
- Context. Clusters of galaxies are effective gravitational lenses able to magnify background galaxies and making it possible to probe the fainter part of the galaxy population. Submillimeter galaxies, which are believed to be star-forming galaxies at typical redshifts of 2 to 3, are a major contaminant to the extended Sunyaev-Zeldovich (SZ) signal of galaxy clusters. For a proper quantification of the SZ signal the contribution of submillimeter galaxies needs to be quantified. Aims. The aims of this study are to identify submillimeter sources in the field of the Bullet cluster (1E 0657-56), a massive cluster of galaxies at z similar or equal to 0.3, measure their flux densities at 870 mu m, and search for counterparts at other wavelengths to constrain their properties. Methods. We carried out deep observations of the submillimeter continuum emission at 870 mu m using the Large APEX BOlometer CAmera (LABOCA) on the Atacama Pathfinder EXperiment (APEX) telescope. Several numerical techniques were used to quantify the noise properties of the data and extract sources. Results. In total, seventeen sources were found. Thirteen of them lie in the central 10 arcmin of the map, which has a pixel sensitivity of 1.2 mJy per 22 '' beam. After correction for flux boosting and gravitational lensing, the number counts are consistent with published submm measurements. Nine of the sources have infrared counterparts in Spitzer maps. The strongest submm detection coincides with a source previously reported at other wavelengths, at an estimated redshift z similar or equal to 2.7. If the submm flux arises from two images of a galaxy magnified by a total factor of 75, as models have suggested, its intrinsic flux would be around 0.6 mJy, consistent with an intrinsic luminosity below 10(12) L-circle dot.
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| 25. |
- Mata, Erika, et al.
(författare)
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Climate Mitigation from Circular and Sharing Economy in the Buildings Sector
- 2020
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Ingår i: Resources, Conservation and Recycling. - : Elsevier BV. - 0921-3449 .- 1879-0658. ; 158
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Tidskriftsartikel (refereegranskat)abstract
- The buildings sector is a major consumer of energy and resources throughout the entire life cycle of the buildings (materials sourcing, design, manufacturing, distribution, consumption, disposal) with corresponding greenhouse gas (GHG) emissions. The contribution of the sector is therefore key to achieving ambitious climate targets. In particular, to maintain global warming below target of 1.5 °C, a carbon dioxide emissions reduction of 9 Gt is required just from the global building sector (Wang et al, 2018). This will need to be achieved by a reduction in energy consumption and decarbonization of electricity production. Equally substantial reductions are required from the other life cycle phases: materials production, construction and demolition phases, which are typically accounted as changes in the industrial sector. The improvement of resource flows through a Circular Economy (CE) approach that includes reducing, reusing, recycling and recovering materials and products, facilitates a decoupling of growth from resource consumption (Kalmykova et al, 2018). This can provide clear advantages from an environmental perspective, contributing to Sustainable Development Goals and to climate change mitigation. However, the literature has identified that despite a global trend of improved operational performance, there are rising “embodied” emissions from processing and manufacturing of building materials. Industrial recycling and energy recovery are the most common practices, even when reuse is believed to have higher economic and environmental value (Eberhardt et al, 2019). The Sharing Economy (SE), offers several opportunities for the building sector by promoting reuse, enabling shared ownership, access or use to increase the utilization rate of products and systems (e.g. shared accommodation, social spaces, offices or tools). Recent literature clearly highlights for the building sector the urgent need for a range of actions across the life cycle such as reduced operational and embodied impacts, as well as strategies to increase alignment of goals and action from numerous stakeholders along the value chain (Röck et al, 2020). This needs to be implemented with specific reference to people, cultures and norms in which the strategies are deployed. The pressure on the sector to embrace its role as provider of critical climate mitigation solutions, is expected to increase. There are however few explicit links to sustainable development and climate mitigation, and little common ground for the variety of analytical approaches and tools. The main aim of the CE in the literature is considered to be economic prosperity, followed by environmental quality; its impact on social equity and future generations is rarely mentioned. Circular and shared economy imply the adoption of cleaner production patterns, an increase of producers’ and consumers’ responsibility and awareness, the use of renewable technologies and materials as well as the adoption of suitable policies. It applies to different systems levels from the macro (neighborhood, city, region, nation and beyond) to the micro level (consumer, product, company). It requires the engagement of all actors in society and their capacity to create and exchange transformative patterns. In all, transition to the era of circular and shared economy aligned with climate goals requires more knowledge on the necessary changes in household’s behavior, design practices, construction and de-construction methods, business models and legal frameworks (Laurenti et al, 2019). This Virtual Special Issue (VSI) calls for new research contributions on mitigation potentials from the Circular and Sharing Economy in the buildings sector worldwide.
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| 26. |
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| 27. |
- Padovani, M., et al.
(författare)
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Adaptable radiative transfer innovations for submillimetre telescopes (ARTIST) Dust polarisation module (DustPol)
- 2012
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Ingår i: Astronomy and Astrophysics. - : EDP Sciences. - 0004-6361 .- 1432-0746. ; 543, s. Article Number: A16 -
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Tidskriftsartikel (refereegranskat)abstract
- We present a new publicly available tool (DustPol) aimed to model the polarised thermal dust emission. The module DustPol, which is publicly available, is part of the ARTIST (Adaptable Radiative Transfer Innovations for Submillimetre Telescopes) package, which also offers tools for modelling the polarisation of line emission together with a model library and a Python-based user interface. DustPol can easily manage analytical as well as pre-gridded models to generate synthetic maps of the Stokes I, Q, and U parameters. These maps are stored in FITS format which is straightforwardly read by the data reduction software used, e. g., by the Atacama Large Millimeter Array (ALMA). This turns DustPol into a powerful engine for the prediction of the expected polarisation features of a source observed with ALMA or the Planck satellite as well as for the interpretation of existing submillimetre observations obtained with other telescopes. DustPol allows the parameterisation of the maximum degree of polarisation and we find that, in a prestellar core, if there is depolarisation, this effect should happen at densities of 10(6) cm(-3) or larger. We compare a model generated by DustPol with the observational polarisation data of the low-mass Class 0 object NGC 1333 IRAS 4A, finding that the total and the polarised emission are consistent.
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