| 1. |
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Overview of the JET results
- 2015
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Ingår i: Nuclear Fusion. - : IOP Publishing. - 0029-5515 .- 1741-4326. ; 55:10
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Tidskriftsartikel (refereegranskat)
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| 2. |
- Ray, S. J., et al.
(författare)
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Muon-spin rotation measurements of the vortex state in Sr2RuO4 : Type-1.5 superconductivity, vortex clustering, and a crossover from a triangular to a square vortex lattice
- 2014
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Ingår i: Physical Review B. Condensed Matter and Materials Physics. - 1098-0121 .- 1550-235X. ; 89:9, s. 094504-
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Tidskriftsartikel (refereegranskat)abstract
- Muon-spin rotation has been used to probe the vortex state in Sr2RuO4. At moderate fields and temperatures a lattice of triangular symmetry is observed, crossing over to a lattice of square symmetry with increasing field and temperature. At lower fields it is found that there are large regions of the sample that are completely free from vortices which grow in volume as the temperature falls. Importantly this is accompanied by increasing vortex density and increasing disorder within the vortex-cluster-containing regions. Both effects are expected to result from the strongly temperature-dependent long-range vortex attractive forces arising from the multiband chiral-order superconductivity.
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| 3. |
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| 4. |
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| 5. |
- Curran, S.J.
(författare)
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Molecular Gas in Seyfert Galaxies
- 2000
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- In this report we present the results of a single dish study of the molecular gas properties in Seyfert galaxies. From the observations of the closest lying example, the Circinus galaxy, we find that about half of the molecular gas is distributed in a circumnuclear ring orbiting the central super-massive black hole, believed to be powering this type 2 Seyfert. The 100 pc-scale ring orbits with non-Keplerian rotation at a maximum velocity of > 180 km s-1. From this we deduce that the NH2/ICO Galactic conversion ratio causes us to overestimate the gas mass fraction by a factor of > 5. From further studies, the remainder of the gas appears to be in a 90° wide outflow which extends to ±500 pc along the rotation axis of the ring. The maximum outflow velocity of 107Lsun and the orientation of the outflow axis suggests that the molecular ring is very nearly coplanar with the central body obscuring the active galactic nucleus. By observing a sample of 20 Seyfert galaxies, we find that the HCN to CO luminosity ratio, LHCN/ LCO > 1/6, is considerably higher than for normal spiral galaxies and comparable to the ratios found in ultra-luminous infra-red galaxies (ULIRGs). Our observations suggest that there may be differences in the molecular gas distributions between low (LFIR ~ 1010 Lsun) and high (LFIR ~ 1011 Lsun) far infra-red luminous (FIR) Seyferts. By combining our results with the FIR luminosities, we find that LFIR/ LCO (LFIR ~ 1011 Lsun Seyferts) > 10LFIR/ LCO (normal spirals) and LFIR/ LHCN (Seyferts) > LFIR/ LHCN (ULIRGs) > LFIR/ LHCN (normal spirals). From this we cannot ascertain the relative radiation contribution of the star-burst and the active nucleus, although between NGC 4945 and Circinus, in which we have performed multi-transitional observations, these seem to differ. This may have the effect of lowering current estimates of the star formation rates in Seyfert galaxies, although both galaxies do appear to have relatively high populations (c.f. the Galaxy) of massive (>10Msun) stars. Finally, estimates of the gas inclinations in these 20 Seyferts appear to suggest that the various gas disk structures on all scales are usually aligned in each galaxy, supporting the notion that the obscuration may be but a dense component of the large-scale gas structure.
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| 6. |
- Curran, S.J., et al.
(författare)
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On the absence of molecular absorption in high-redshift millimetre-band searches
- 2011
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Ingår i: Monthly Notices of the Royal Astronomical Society. - : Oxford University Press (OUP). - 0035-8711 .- 1365-2966. ; 416:3, s. 2143-2153
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Tidskriftsartikel (refereegranskat)abstract
- We have undertaken a search for millimetre-waveband absorption (through the CO and HCO(+) rotational transitions) in the host galaxies of reddened radio sources (z = 0.405-1.802). Despite the colour selection (optical-near-infrared colours of V - K greater than or similar to 5 in all but one source), no absorption was found in any of the eight quasars for which the background continuum flux was detected. On the basis of the previous (mostly intervening) H(2) and OH detections, the limits reached here and in some previous surveys should be deep enough to detect molecular absorption according to their V - K colours. However, our survey makes the assumption that the reddening is associated with dust close to the emission redshift of the quasar and that the narrow millimetre component of this emission is intercepted by the compact molecular cores. By using the known millimetre absorbers to define the colour depth and comparing this with the ultraviolet luminosities of the sources, we find that, even if these assumptions are valid, only 12 of the 40 objects (mainly from this work) are potentially detectable. This is assuming an excitation temperature of T(x) = 10 K at z = 0, with the number decreasing with increasing temperatures (to zero detectable at T(x) greater than or similar to 100 K).
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| 7. |
- Curran, S.J., et al.
(författare)
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Redshifted H I and OH absorption in radio galaxies and quasars
- 2011
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Ingår i: Monthly Notices of the Royal Astronomical Society. - : Oxford University Press (OUP). - 0035-8711 .- 1365-2966. ; 413:2, s. 1165-1173
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Tidskriftsartikel (refereegranskat)abstract
- From a survey for the redshifted H i 21-cm and OH 18-cm absorption in the hosts of a sample of radio galaxies and quasars, we detect H i in three of the 10 and OH in none of the 14 sources for which useful data were obtained. As expected from our recent result, all of the 21-cm detections occur in sources with ultraviolet (UV) continuum luminosities of L(UV) 1023 W Hz-1. Our 21-cm detections in combination with those previously published give a total of eight (associated and intervening) H i-absorbing sources searched and undetected in OH. Using the detected 21-cm line strengths to normalize the limits, we find that only two of these eight sources may have been searched sufficiently deeply in OH, even though these are marginal.
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| 8. |
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| 9. |
- Emile-Geay, J., et al.
(författare)
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Data Descriptor: A global multiproxy database for temperature reconstructions of the Common Era
- 2017
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Ingår i: Scientific Data. - : Springer Science and Business Media LLC. - 2052-4463. ; 4
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Tidskriftsartikel (refereegranskat)abstract
- Reproducible climate reconstructions of the Common Era (1 CE to present) are key to placing industrial-era warming into the context of natural climatic variability. Here we present a community-sourced database of temperature-sensitive proxy records from the PAGES2k initiative. The database gathers 692 records from 648 locations, including all continental regions and major ocean basins. The records are from trees, ice, sediment, corals, speleothems, documentary evidence, and other archives. They range in length from 50 to 2000 years, with a median of 547 years, while temporal resolution ranges from biweekly to centennial. Nearly half of the proxy time series are significantly correlated with HadCRUT4.2 surface temperature over the period 1850-2014. Global temperature composites show a remarkable degree of coherence between high-and low-resolution archives, with broadly similar patterns across archive types, terrestrial versus marine locations, and screening criteria. The database is suited to investigations of global and regional temperature variability over the Common Era, and is shared in the Linked Paleo Data (LiPD) format, including serializations in Matlab, R and Python. Since the pioneering work of D'Arrigo and Jacoby1-3, as well as Mann et al. 4,5, temperature reconstructions of the Common Era have become a key component of climate assessments6-9. Such reconstructions depend strongly on the composition of the underlying network of climate proxies10, and it is therefore critical for the climate community to have access to a community-vetted, quality-controlled database of temperature-sensitive records stored in a self-describing format. The Past Global Changes (PAGES) 2k consortium, a self-organized, international group of experts, recently assembled such a database, and used it to reconstruct surface temperature over continental-scale regions11 (hereafter, ` PAGES2k-2013'). This data descriptor presents version 2.0.0 of the PAGES2k proxy temperature database (Data Citation 1). It augments the PAGES2k-2013 collection of terrestrial records with marine records assembled by the Ocean2k working group at centennial12 and annual13 time scales. In addition to these previously published data compilations, this version includes substantially more records, extensive new metadata, and validation. Furthermore, the selection criteria for records included in this version are applied more uniformly and transparently across regions, resulting in a more cohesive data product. This data descriptor describes the contents of the database, the criteria for inclusion, and quantifies the relation of each record with instrumental temperature. In addition, the paleotemperature time series are summarized as composites to highlight the most salient decadal-to centennial-scale behaviour of the dataset and check mutual consistency between paleoclimate archives. We provide extensive Matlab code to probe the database-processing, filtering and aggregating it in various ways to investigate temperature variability over the Common Era. The unique approach to data stewardship and code-sharing employed here is designed to enable an unprecedented scale of investigation of the temperature history of the Common Era, by the scientific community and citizen-scientists alike.
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| 10. |
- Justice, A. E., et al.
(författare)
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Genome-wide meta-analysis of 241,258 adults accounting for smoking behaviour identifies novel loci for obesity traits
- 2017
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Ingår i: Nature Communications. - : Springer Science and Business Media LLC. - 2041-1723. ; 8
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Tidskriftsartikel (refereegranskat)abstract
- Few genome-wide association studies (GWAS) account for environmental exposures, like smoking, potentially impacting the overall trait variance when investigating the genetic contribution to obesity-related traits. Here, we use GWAS data from 51,080 current smokers and 190,178 nonsmokers (87% European descent) to identify loci influencing BMI and central adiposity, measured as waist circumference and waist-to-hip ratio both adjusted for BMI. We identify 23 novel genetic loci, and 9 loci with convincing evidence of gene-smoking interaction (GxSMK) on obesity-related traits. We show consistent direction of effect for all identified loci and significance for 18 novel and for 5 interaction loci in an independent study sample. These loci highlight novel biological functions, including response to oxidative stress, addictive behaviour, and regulatory functions emphasizing the importance of accounting for environment in genetic analyses. Our results suggest that tobacco smoking may alter the genetic susceptibility to overall adiposity and body fat distribution.
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