131 research outputs found
NIR Tully-Fisher in the Zone of Avoidance. - II. 21 cm HI-line spectra of southern ZOA galaxies
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 TullyâFisher in the Zone of Avoidance â II. 21 cm Hâi-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
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
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
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
We present Spitzer 3.6 and 4.5 m 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
m 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 7.33
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 m photometry, along with positionally matched and
photometry from USNO-B; , , and photometry from 2MASS; and ,
, , and photometry from the WISE all-sky catalog
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âCaution! The Bread is Poisonedâ: The Hong Kong Mass Poisoning of January 1857
This article examines the Hong Kong mass poisoning of 15 January 1857, in which bread from a Chinese bakery that supplied the colonial community was adulterated with arsenic. Even though there is a wealth of printed and manuscript documentation available many vital aspects of the poisoning remain unclear. What kind of incident was it: an act of terrorism and attempted mass murder, a war crime, a criminal conspiracy, an act of commercial sabotage, an accident or even an imagined or imaginary event? Throughout, our focus remains firmly fixed on the central act of the poisoning itself and on what it reveals about the precarious nature of early colonial Hong Kong. Interpretations have swarmed over the available âfacts'. Equally ironic is what happened to the afterlife of how the event was understood. This article seeks to rescue the Hong Kong poisoning from being a freakish and isolated footnote of only local interest. Accepting this historical verdict would be a mistake as it is of significance not only at a local level, but geopolitically in Britain and across the empire
2MTF â II. New Parkes 21-cm observations of 303 southern galaxies
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
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 2000â2016, biological and social scientists worked to increase the protected proportion of Peruâs 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 residentsâ 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
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 m (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 (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 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 , CatWISE2020 motions are accurate at
the 20 mas yr level for W115 mag sources, and at the mas
yr level for W117 mag sources. This level of precision represents
a 12 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 and Data
CatWISE is a program to catalog sources selected from combined
and all-sky survey data at 3.4 and 4.6 m (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 , 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 , 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 and 30 mas
yr 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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