131 research outputs found

    NIR Tully-Fisher in the Zone of Avoidance. - II. 21 cm HI-line spectra of southern ZOA galaxies

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    This article has been accepted for publication in Monthly Notices of the Royal Astronomical Society © : 2016 [Khaled Said, Renee C. Kraan-Korteweg, Lister Staveley-Smith, Wendy L. Williams, T. H . Jarrett, Christopher M. Springob, 'NIR Tully–Fisher in the Zone of Avoidance – II. 21 cm H i-line spectra of southern ZOA galaxies', MNRAS (2016) 457(3): 2366-2377]. Published by Oxford University Press on behalf of the Royal Astronomical Society. All rights reserved. The version of record is available on line via doi: https:doi.org/10.1093/mnras/stw105High-accuracy H I profiles and linewidths are presented for inclined ((b/a) o 5) for use in TF distance estimation. The average value of the signal-to-noise ratio of the sample is 14.7. We present the H I parameters for these galaxies. The sample will allow a more accurate determination of the flow field in the southern ZOA which bisects dynamically important large-scale structures such as Puppis, the Great Attractor, and the Local Void.Peer reviewedFinal Published versio

    Spiral-Induced Star Formation in the Outer Disks of Galaxies

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    The outer regions of galactic disks have received increased attention since ultraviolet observations with GALEX demonstrated that nearly 30% of galaxies have UV emission beyond their optical extents, indicating star formation activity. These galaxies have been termed extended UV (XUV) disks. Here, we address whether these observations contradict the gas surface density threshold for star formation inferred from Halpha radial profiles of galaxies. We run smoothed particle hydrodynamics simulations of isolated disk galaxies with fiducial star formation prescriptions and show that over-densities owing to the presence of spiral structure can induce star formation in extended gas disks. For direct comparison with observations, we use the 3-D radiative transfer code Sunrise to create simulated FUV and K_s band images. We find that galaxies classified as Type I XUV disks are a natural consequence of spiral patterns, but we are unable to reproduce Type II XUV disks. We also compare our results to studies of the Kennicutt-Schmidt relation in outer disks.Comment: Published in Ap

    A T8.5 Brown Dwarf Member of the Xi Ursae Majoris System

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    The Wide-field Infrared Survey Explorer has revealed a T8.5 brown dwarf (WISE J111838.70+312537.9) that exhibits common proper motion with a solar-neighborhood (8 pc) quadruple star system - Xi Ursae Majoris. The angular separation is 8.5 arc-min, and the projected physical separation is about 4000 AU. The sub-solar metallicity and low chromospheric activity of Xi UMa A argue that the system has an age of at least 2 Gyr. The infrared luminosity and color of the brown dwarf suggests the mass of this companion ranges between 14 and 38 Jupiter masses for system ages of 2 and 8 Gyr respectively.Comment: AJ in press, 12 pages LaTeX with 6 figures. More astrometric data and a laser guide star adaptive optics image adde

    Understanding the UK hospital supply chain in an era of patient choice

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    Author Posting © Westburn Publishers Ltd, 2011. This is a post-peer-review, pre-copy-edit version of an article which has been published in its definitive form in the Journal of Marketing Management, and has been posted by permission of Westburn Publishers Ltd for personal use, not for redistribution. The article was published in Journal of Marketing Management, 27(3-4), 401 - 423, doi:10.1080/0267257X.2011.547084 http://dx.doi.org/10.1080/0267257X.2011.547084The purpose of this paper is to investigate the UK hospital supply chain in light of recent government policy reform where patients will have, inter alia, greater choice of hospital for elective surgery. Subsequently, the hospital system should become far more competitive with supply chains having to react to these changes as patient demand becomes less predictable. Using a qualitative case study methodology, hospital managers are interviewed on a range of issues. Views on the development of the hospital supply chain in different phases are derived, and are used to develop a map of the current hospital chain. The findings show hospital managers anticipating some significant changes to the hospital supply chain and its workings as Patient Choice expands. The research also maps the various aspects of the hospital supply chain as it moves through different operational phases and highlights underlying challenges and complexities. The hospital supply chain, as discussed and mapped in this research, is original work given there are no examples in the literature that provide holistic representations of hospital activity. At the end, specific recommendations are provided that will be of interest to service to managers, researchers, and policymakers

    Spitzer Photometry of WISE-Selected Brown Dwarf and Hyper-Luminous Infrared Galaxy Candidates

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    We present Spitzer 3.6 and 4.5 ÎŒ\mum photometry and positions for a sample of 1510 brown dwarf candidates identified by the WISE all-sky survey. Of these, 166 have been spectroscopically classified as objects with spectral types M(1), L(7), T(146), and Y(12); Sixteen other objects are non-(sub)stellar in nature. The remainder are most likely distant L and T dwarfs lacking spectroscopic verification, other Y dwarf candidates still awaiting follow-up, and assorted other objects whose Spitzer photometry reveals them to be background sources. We present a catalog of Spitzer photometry for all astrophysical sources identified in these fields and use this catalog to identify 7 fainter (4.5 ÎŒ\mum ∌\sim 17.0 mag) brown dwarf candidates, which are possibly wide-field companions to the original WISE sources. To test this hypothesis, we use a sample of 919 Spitzer observations around WISE-selected high-redshift hyper-luminous infrared galaxy (HyLIRG) candidates. For this control sample we find another 6 brown dwarf candidates, suggesting that the 7 companion candidates are not physically associated. In fact, only one of these 7 Spitzer brown dwarf candidates has a photometric distance estimate consistent with being a companion to the WISE brown dwarf candidate. Other than this there is no evidence for any widely separated (>> 20 AU) ultra-cool binaries. As an adjunct to this paper, we make available a source catalog of ∌\sim 7.33 ×105\times 10^5 objects detected in all of these Spitzer follow-up fields for use by the astronomical community. The complete catalog includes the Spitzer 3.6 and 4.5 ÎŒ\mum photometry, along with positionally matched BB and RR photometry from USNO-B; JJ, HH, and KsK_s photometry from 2MASS; and W1W1, W2W2, W3W3, and W4W4 photometry from the WISE all-sky catalog

    2MTF – II. New Parkes 21-cm observations of 303 southern galaxies

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    We present new 21-cm neutral hydrogen (HI) observations of spiral galaxies for the 2MASS Tully Fisher (2MTF) survey. Using the 64-m Parkes radio telescope multibeam system we obtain 152 high signal-to-noise HI spectra from which we extract 148 high-accuracy (< 5% error) velocity widths and derive reliable rotation velocities. The observed sample consists of 303 southern (\delta < -40\deg) galaxies selected from the MASS Redshift Survey (2MRS) with K_s <11.25 mag, cz < 10,000 km/s and axis ratio b/a < 0.5. The HI observations reported in this paper will be combined with new HI spectra from the Green Bank and Arecibo telescopes, together producing the most uniform Tully-Fisher survey ever constructed (in terms of sky coverage). In particular, due to its near infrared selection, 2MTF will be significantly more complete at low Galactic latitude (|b|<15\deg) and will provide a more reliable map of peculiar velocities in the local universe.Comment: 11 pages, 12 figures, 3 tables, accepted for publication in MNRA

    Applied science facilitates the large-scale expansion of protected areas in an Amazonian hot spot

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    Meeting international commitments to protect 17% of terrestrial ecosystems worldwide will require \u3e3 million square kilometers of new protected areas and strategies to create those areas in a way that respects local communities and land use. In 2000–2016, biological and social scientists worked to increase the protected proportion of Peru’s largest department via 14 interdisciplinary inventories covering \u3e9 million hectares of this megadiverse corner of the Amazon basin. In each landscape, the strategy was the same: convene diverse partners, identify biological and sociocultural assets, document residents’ use of natural resources, and tailor the findings to the needs of decision-makers. Nine of the 14 landscapes have since been protected (5.7 million hectares of new protected areas), contributing to a quadrupling of conservation coverage in Loreto (from 6 to 23%). We outline the methods and enabling conditions most crucial for successfully applying similar campaigns elsewhere on Earth

    The CatWISE2020 Catalog

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    The CatWISE2020 Catalog consists of 1,890,715,640 sources over the entire sky selected from WISE and NEOWISE survey data at 3.4 and 4.6 ÎŒ\mum (W1 and W2) collected from 2010 Jan. 7 to 2018 Dec. 13. This dataset adds two years to that used for the CatWISE Preliminary Catalog (Eisenhardt et al., 2020), bringing the total to six times as many exposures spanning over sixteen times as large a time baseline as the AllWISE catalog. The other major change from the CatWISE Preliminary Catalog is that the detection list for the CatWISE2020 Catalog was generated using crowdsource{\it crowdsource} (Schlafly et al. 2019), while the CatWISE Preliminary Catalog used the detection software used for AllWISE. These two factors result in roughly twice as many sources in the CatWISE2020 Catalog. The scatter with respect to Spitzer{\it Spitzer} photometry at faint magnitudes in the COSMOS field, which is out of the Galactic plane and at low ecliptic latitude (corresponding to lower WISE coverage depth) is similar to that for the CatWISE Preliminary Catalog. The 90% completeness depth for the CatWISE2020 Catalog is at W1=17.7 mag and W2=17.5 mag, 1.7 mag deeper than in the CatWISE Preliminary Catalog. From comparison to Gaia{\it Gaia}, CatWISE2020 motions are accurate at the 20 mas yr−1^{-1} level for W1∌\sim15 mag sources, and at the ∌100\sim100 mas yr−1^{-1} level for W1∌\sim17 mag sources. This level of precision represents a 12×\times improvement over AllWISE. The CatWISE catalogs are available in the WISE/NEOWISE Enhanced and Contributed Products area of the NASA/IPAC Infrared Science Archive.Comment: 27 pages, 24 figure, 2 tables. Accepted for publication in ApJS. arXiv admin note: text overlap with arXiv:1908.0890

    The CatWISE Preliminary Catalog: Motions from WISE{\it WISE} and NEOWISE{\it NEOWISE} Data

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    CatWISE is a program to catalog sources selected from combined WISE{\it WISE} and NEOWISE{\it NEOWISE} all-sky survey data at 3.4 and 4.6 ÎŒ\mum (W1 and W2). The CatWISE Preliminary Catalog consists of 900,849,014 sources measured in data collected from 2010 to 2016. This dataset represents four times as many exposures and spans over ten times as large a time baseline as that used for the AllWISE Catalog. CatWISE adapts AllWISE software to measure the sources in coadded images created from six-month subsets of these data, each representing one coverage of the inertial sky, or epoch. The catalog includes the measured motion of sources in 8 epochs over the 6.5 year span of the data. From comparison to Spitzer{\it Spitzer}, the SNR=5 limits in magnitudes in the Vega system are W1=17.67 and W2=16.47, compared to W1=16.96 and W2=16.02 for AllWISE. From comparison to Gaia{\it Gaia}, CatWISE positions have typical accuracies of 50 mas for stars at W1=10 mag and 275 mas for stars at W1=15.5 mag. Proper motions have typical accuracies of 10 mas yr−1^{-1} and 30 mas yr−1^{-1} for stars with these brightnesses, an order of magnitude better than from AllWISE. The catalog is available in the WISE/NEOWISE Enhanced and Contributed Products area of the NASA/IPAC Infrared Science Archive.Comment: 53 pages, 20 figures, 5 tables. Accepted by ApJ
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