52 research outputs found
A Rare Presentation of Pellet Injury in the Neck
Penetrating neck injuries are dangerous and deserve emergency treatment by virtue of the vital structures present underneath. There is a potential risk of unrecognized vascular injury and retained foreign bodies with their associated complications in these wounds. Therefore, an early diagnostic workup to localize the site of injury and an immediate neck exploration are important
The Evolution of the Intracluster Medium Metallicity in Sunyaev-Zel'dovich-Selected Galaxy Clusters at 0 < z < 1.5
We present the results of an X-ray spectral analysis of 153 galaxy clusters
observed with the Chandra, XMM-Newton, and Suzaku space telescopes. These
clusters, which span 0 < z < 1.5, were drawn from a larger, mass-selected
sample of galaxy clusters discovered in the 2500 square degree South Pole
Telescope Sunyaev Zel'dovich (SPT-SZ) survey. With a total combined exposure
time of 9.1 Ms, these data yield the strongest constraints to date on the
evolution of the metal content of the intracluster medium (ICM). We find no
evidence for strong evolution in the global (r<R500) ICM metallicity (dZ/dz =
-0.06 +/- 0.04 Zsun), with a mean value at z=0.6 of = 0.23 +/- 0.01 Zsun
and a scatter of 0.08 +/- 0.01 Zsun. These results imply that >60% of the
metals in the ICM were already in place at z=1 (at 95% confidence), consistent
with the picture of an early (z>1) enrichment. We find, in agreement with
previous works, a significantly higher mean value for the metallicity in the
centers of cool core clusters versus non-cool core clusters. We find weak
evidence for evolution in the central metallicity of cool core clusters (dZ/dz
= -0.21 +/- 0.11 Zsun), which is sufficient to account for this enhanced
central metallicity over the past ~10 Gyr. We find no evidence for metallicity
evolution outside of the core (dZ/dz = -0.03 +/- 0.06 Zsun), and no significant
difference in the core-excised metallicity between cool core and non-cool core
clusters. This suggests that strong radio-mode AGN feedback does not
significantly alter the distribution of metals at r>0.15R500. Given the
limitations of current-generation X-ray telescopes in constraining the ICM
metallicity at z>1, significant improvements on this work will likely require
next-generation X-ray missions.Comment: 11 pages, 8 figures, 2 tables. Submitted to ApJ. Comments welcome
Acinic Cell Carcinoma with Extensive Neuroendocrine Differentiation: A Diagnostic Challenge
Primary salivary gland carcinoma with neuroendocrine differentiation is of rare occurrence, especially so in the parotid gland. Amongst the various reported primary tumors with neuroendocrine differentiation, acinic cell carcinoma (ACC) one such tumor. A 48 year old lady presented with a gradually increasing right infra-auricular swelling for a period of 1 year which enlarged suddenly in a short period. Contrast Enhanced Computed Tomography (CECT) suggested diagnosis of Pleomorphic Adenoma. Fine Needle Aspiration Cytology (FANC) yielded a cystic fluid suggesting a possibility of Warthin’s tumor or Oncocytic lesion. Intraoperative findings were suggestive of a Warthin’s tumor. Initial histopathological examination of the tumor was suggestive of neuroendocrine carcinoma. However, extensive sectioning revealed peripheral islands of ACC. Immunoexpression of S-100, Neuron specific Enolase (NSE), Chromogranin A and Synaptophysin confirmed the diagnosis. The possibility of neuroendocrine differentiation in a primary salivary gland tumor should be kept in mind whenever a salivary gland tumor shows only neuroendocrine histology
Constraining radio mode feedback in galaxy clusters with the cluster radio AGNs properties to z ∼ 1
We study the properties of the Sydney University Molonglo Sky Survey (SUMSS) 843 MHz radio active galactic nuclei (AGNs) population in galaxy clusters from two large catalogues created using the Dark Energy Survey (DES): ∼11 800 optically selected RM-Y3 and ∼1000 X-ray selected MARD-Y3 clusters. We show that cluster radio loud AGNs are highly concentrated around cluster centres to z ∼ 1. We measure the halo occupation number for cluster radio AGNs above a threshold luminosity, finding that the number of radio AGNs per cluster increases with cluster halo mass as N ∝ M1.2 ± 0.1 (N ∝ M0.68 ± 0.34) for the RM-Y3 (MARD-Y3) sample. Together, these results indicate that radio mode feedback is favoured in more massive galaxy clusters. Using optical counterparts for these sources, we demonstrate weak redshift evolution in the host broad-band colours and the radio luminosity at fixed host galaxy stellar mass. We use the redshift evolution in radio luminosity to break the degeneracy between density and luminosity evolution scenarios in the redshift trend of the radio AGNs luminosity function (LF). The LF exhibits a redshift trend of the form (1 + z)γ in density and luminosity, respectively, of γD = 3.0 ± 0.4 and γP = 0.21 ± 0.15 in the RM-Y3 sample, and γD = 2.6 ± 0.7 and γP = 0.31 ± 0.15 in MARD-Y3. We discuss the physical drivers of radio mode feedback in cluster AGNs, and we use the cluster radio galaxy LF to estimate the average radio-mode feedback energy as a function of cluster mass and redshift and compare it to the core (<0.1R500) X-ray radiative losses for clusters at z < 1
Cluster Cosmology Constraints from the 2500 deg SPT-SZ Survey: Inclusion of Weak Gravitational Lensing Data from Magellan and the Hubble Space Telescope
We derive cosmological constraints using a galaxy cluster sample selected
from the 2500~deg SPT-SZ survey. The sample spans the redshift range . The
sample is supplemented with optical weak gravitational lensing measurements of
32 clusters with (from Magellan and HST) and X-ray measurements
of 89 clusters with (from Chandra). We rely on minimal modeling
assumptions: i) weak lensing provides an accurate means of measuring halo
masses, ii) the mean SZ and X-ray observables are related to the true halo mass
through power-law relations in mass and dimensionless Hubble parameter
with a-priori unknown parameters, iii) there is (correlated, lognormal)
intrinsic scatter and measurement noise relating these observables to their
mean relations. We simultaneously fit for these astrophysical modeling
parameters and for cosmology. Assuming a flat CDM model, in which
the sum of neutrino masses is a free parameter, we measure
, , and
. The redshift evolution
of the X-ray -mass and -mass relations are both
consistent with self-similar evolution to within . The mass-slope of
the -mass relation shows a deviation from
self-similarity. Similarly, the mass-slope of the -mass
relation is steeper than self-similarity at the level. In a CDM cosmology, we measure the dark energy equation of state parameter
from the cluster data. We perform a measurement of the growth
of structure since redshift and find no evidence for tension with
the prediction from General Relativity. We provide updated redshift and mass
estimates for the SPT sample. (abridged)Comment: Accepted for publication in ApJ (v2 is accepted version), the catalog
can be found at https://pole.uchicago.edu/public/data/sptsz-clusters
The Eighteenth Data Release of the Sloan Digital Sky Surveys: Targeting and First Spectra from SDSS-V
The eighteenth data release of the Sloan Digital Sky Surveys (SDSS) is the
first one for SDSS-V, the fifth generation of the survey. SDSS-V comprises
three primary scientific programs, or "Mappers": Milky Way Mapper (MWM), Black
Hole Mapper (BHM), and Local Volume Mapper (LVM). This data release contains
extensive targeting information for the two multi-object spectroscopy programs
(MWM and BHM), including input catalogs and selection functions for their
numerous scientific objectives. We describe the production of the targeting
databases and their calibration- and scientifically-focused components. DR18
also includes ~25,000 new SDSS spectra and supplemental information for X-ray
sources identified by eROSITA in its eFEDS field. We present updates to some of
the SDSS software pipelines and preview changes anticipated for DR19. We also
describe three value-added catalogs (VACs) based on SDSS-IV data that have been
published since DR17, and one VAC based on the SDSS-V data in the eFEDS field.Comment: Accepted to ApJ
Baryon content in a sample of 91 galaxy clusters selected by the South Pole Telescope at 0.2 <z < 1.25
We estimate total mass (M500), intracluster medium (ICM) mass (MICM), and stellar mass (M) in a Sunyaev–Zel’dovich effect (SZE) selected sample of 91 galaxy clusters with masses M500 2.5 × 1014 M and redshift 0.2 < z < 1.25 from the 2500 deg2 South Pole Telescope SPT-SZ survey. The total masses M500 are estimated from the SZE observable, the ICM masses MICM are obtained from the analysis of Chandra X-ray observations, and the stellar masses M are derived by fitting spectral energy distribution templates to Dark Energy Survey griz optical photometry and WISE or Spitzer near-infrared photometry. We study trends in the stellar mass, the ICM mass, the total baryonic mass, and the cold baryonic fraction with cluster halo mass and redshift. We find significant departures from self-similarity in the mass scaling for all quantities, while the redshift trends are all statistically consistent with zero, indicating that the baryon content of clusters at fixed mass has changed remarkably little over the past ≈9 Gyr. We compare our results to the mean baryon fraction (and the stellar mass fraction) in the field, finding that these values lie above (below) those in cluster virial regions in all but the most massive clusters at low redshift. Using a simple model of the matter assembly of clusters from infalling groups with lower masses and from infalling material from the low-density environment or field surrounding the parent haloes, we show that the measured mass trends without strong redshift trends in the stellar mass scaling relation could be explained by a mass and redshift dependent fractional contribution from field material. Similar analyses of the ICM and baryon mass scaling relations provide evidence for the so-called ‘missing baryons’ outside cluster virial regions
The eighteenth data release of the Sloan Digital Sky Surveys : targeting and first spectra from SDSS-V
The eighteenth data release of the Sloan Digital Sky Surveys (SDSS) is the first one for SDSS-V, the fifth generation of the survey. SDSS-V comprises three primary scientific programs, or "Mappers": Milky Way Mapper (MWM), Black Hole Mapper (BHM), and Local Volume Mapper (LVM). This data release contains extensive targeting information for the two multi-object spectroscopy programs (MWM and BHM), including input catalogs and selection functions for their numerous scientific objectives. We describe the production of the targeting databases and their calibration- and scientifically-focused components. DR18 also includes ~25,000 new SDSS spectra and supplemental information for X-ray sources identified by eROSITA in its eFEDS field. We present updates to some of the SDSS software pipelines and preview changes anticipated for DR19. We also describe three value-added catalogs (VACs) based on SDSS-IV data that have been published since DR17, and one VAC based on the SDSS-V data in the eFEDS field.Publisher PDFPeer reviewe
Constraining radio mode feedback in galaxy clusters with the cluster radio AGNs properties to z similar to 1
We study the properties of the Sydney University Molonglo Sky Survey (SUMSS) 843 MHz radio active galactic nuclei (AGNs) population in galaxy clusters from two large catalogues created using the Dark Energy Survey (DES): similar to 11 800 optically selected RM-Y3 and similar to 1000 X-ray selected MARD-Y3 clusters. We show that cluster radio loud AGNs are highly concentrated around cluster centres to z similar to 1. We measure the halo occupation number for cluster radio AGNs above a threshold luminosity, finding that the number of radio AGNs per cluster increases with cluster halo mass as N proportional to M-1(.2 +/- 0.1) (N proportional to M-0.(68 +/- 0.34)) for the RM-Y3 (MARD-Y3) sample. Together, these results indicate that radio mode feedback is favoured in more massive galaxy clusters. Using optical counterparts for these sources, we demonstrate weak redshift evolution in the host broad-band colours and the radio luminosity at fixed host galaxy stellar mass. We use the redshift evolution in radio luminosity to break the degeneracy between density and luminosity evolution scenarios in the redshift trend of the radio AGNs luminosity function (LF). The LF exhibits a redshift trend of the form (1 + z)(gamma) in density and luminosity, respectively, of gamma(D) = 3.0 +/- 0.4 and gamma(P) = 0.21 +/- 0.15 in the RM-Y3 sample, and gamma(D) = 2.6 +/- 0.7 and gamma(P) = 0.31 +/- 0.15 in MARD-Y3. We discuss the physical drivers of radio mode feedback in cluster AGNs, and we use the cluster radio galaxy LF to estimate the average radio-mode feedback energy as a function of cluster mass and redshift and compare it to the core
- …