1,893 research outputs found
The Multiwavelength Survey By Yale-Chile (MUSYC) Wide K-Band Imaging, Photometric Catalogs, Clustering, And Physical Properties Of Galaxies At Z Similar To 2
We present K-band imaging of two similar to 30' x 30' fields covered by the Multiwavelength Survey by Yale-Chile (MUSYC) Wide NIR Survey. The SDSS 1030+05 and Cast 1255 fields were imaged with the Infrared Side Port Imager (ISPI) on the 4 m Blanco telescope at the Cerro Tololo Inter-American Observatory (CTIO) to a 5 sigma point-source limiting depth of K similar to 20 (Vega). Combining these data with the MUSYC optical UBVRIz imaging, we created multiband K-selected source catalogs for both fields. These catalogs, together with the MUSYC K-band catalog of the Extended Chandra Deep Field South (ECDF-S) field, were used to select K 20 BzK galaxies over an area of 0.71 deg(2). This is the largest area ever surveyed for BzK galaxies. We present number counts, redshift distributions, and stellar masses for our sample of 3261 BzK galaxies (2502 star-forming [sBzK] and 759 passively evolving [pBzK]), as well as reddening and star formation rate estimates for the star-forming BzK systems. We also present two-point angular correlation functions and spatial correlation lengths for both sBzK and pBzK galaxies and show that previous estimates of the correlation function of these galaxies were affected by cosmic variance due to the small areas surveyed. We have measured correlation lengths r(0) of 8.89 +/- 2.03 and 10.82 +/- 1.72 Mpc for sBzK and pBzK galaxies, respectively. This is the first reported measurement of the spatial correlation function of passive BzK galaxies. In the Lambda CDM scenario of galaxy formation, these correlation lengths at z similar to 2 translate into minimum masses of similar to 4 x 10(12) and similar to 9 x 10(12) M(circle dot) for the dark matter halos hosting sBzK and pBzK galaxies, respectively. The clustering properties of the galaxies in our sample are consistent with their being the descendants of bright Lyman break galaxies at z similar to 3, and the progenitors of present-day > 1L* galaxies.Astronom
The XXL Survey V: Detection of the Sunyaev-Zel'dovich effect of the Redshift 1.9 Galaxy Cluster XLSSU J021744.1-034536 with CARMA
We report the detection of the Sunyaev-Zel'dovich (SZ) effect of galaxy
cluster XLSSU J021744.1-034536, using 30 GHz CARMA data. This cluster was
discovered via its extended X-ray emission in the XMM-Newton Large Scale
Structure survey, the precursor to the XXL survey. It has a photometrically
determined redshift , making it among the most distant
clusters known, and nominally the most distant for which the SZ effect has been
measured. The spherically integrated Comptonization is
, a measurement which is relatively
insensitive to assumptions regarding the size and redshift of the cluster, as
well as the background cosmology. Using a variety of locally calibrated cluster
scaling relations extrapolated to z~2, we estimate a mass - from the X-ray flux and SZ signal. The measured
properties of this cluster are in good agreement with the extrapolation of an
X-ray luminosity-SZ effect scaling relation calibrated from clusters discovered
by the South Pole Telescope at higher masses and lower redshifts. The full
XXL-CARMA sample will provide a more complete, multi-wavelength census of
distant clusters in order to robustly extend the calibration of cluster scaling
relations to these high redshifts.Comment: ApJ, in press. 9 pages, 4 figures, 4 table
Three intervening galaxy absorbers towards GRB060418: faint and dusty?
We present an analysis of three strong, intervening Mg II absorption systems
(z_abs = 0.603, 0.656, 1.107) towards the optical afterglow of gamma-ray burst
(GRB) 060418. From high resolution UVES spectra we measure metal column
densities and find that the highest redshift absorber exhibits a large amount
of dust depletion compared with DLAs seen in QSO spectra. The intervening z_abs
= 1.107 absorber is also unusual in exhibiting a clear 2175 A bump, the first
time this feature has been definitively detected in a GRB spectrum. The GRB
afterglow spectrum is best fit with a two component extinction curve: an SMC
extinction law at z=1.49 (the redshift of the host) with E(B-V) = 0.07+-0.01
and a Galactic extinction curve at z ~ 1.1 with E(B-V) = 0.08+-0.01. We also
present a moderately deep NTT R-band image of the GRB060418 field and
spectroscopy of four galaxies within 1 arcminute. None of these objects has a
redshift that matches any of the intervening absorbers, and we conclude that
the galaxies responsible for the two intervening Mg II absorbers at z ~ 0.6
have luminosities ~<0.3 L^star.Comment: Accepted for publication in MNRAS (Letters), 5 pages. Updated with
more accurate host positio
The Multiwavelength Survey by Yale-Chile (MUSYC): Deep Near-Infrared Imaging and the Selection of Distant Galaxies
We present deep near-infrared JHK imaging of four 10'x10' fields. The
observations were carried out as part of the Multiwavelength Survey by
Yale-Chile (MUSYC) with ISPI on the CTIO 4m telescope. The typical point source
limiting depths are J~22.5, H~21.5, and K~21 (5sigma; Vega). The effective
seeing in the final images is ~1.0". We combine these data with MUSYC UBVRIz
imaging to create K-selected catalogs that are unique for their uniform size,
depth, filter coverage, and image quality. We investigate the rest-frame
optical colors and photometric redshifts of galaxies that are selected using
common color selection techniques, including distant red galaxies (DRGs),
star-forming and passive BzKs, and the rest-frame UV-selected BM, BX, and Lyman
break galaxies (LBGs). These techniques are effective at isolating large
samples of high redshift galaxies, but none provide complete or uniform samples
across the targeted redshift ranges. The DRG and BM/BX/LBG criteria identify
populations of red and blue galaxies, respectively, as they were designed to
do. The star-forming BzKs have a very wide redshift distribution, a wide range
of colors, and may include galaxies with very low specific star formation
rates. In comparison, the passive BzKs are fewer in number, have a different
distribution of K magnitudes, and have a somewhat different redshift
distribution. By combining these color selection criteria, it appears possible
to define a reasonably complete sample of galaxies to our flux limit over
specific redshift ranges. However, the redshift dependence of both the
completeness and sampled range of rest-frame colors poses an ultimate limit to
the usefulness of these techniques.Comment: 17 pages in emulateapj style, 13 figures. Submitted to the
Astronomical Journal. Data will be made available upon publicatio
Luminosity Functions of XMM-LSS C1 Galaxy Clusters
CFHTLS optical photometry has been used to study the galaxy luminosity
functions of 14 X-ray selected clusters from the XMM-LSS survey. These are
mostly groups and poor clusters, with masses (M_{500}) in the range 0.6 to
19x10 ^{13} M_solar and redshifts 0.05-0.61. Hence these are some of the
highest redshift X-ray selected groups to have been studied. Lower and upper
colour cuts were used to determine cluster members. We derive individual
luminosity functions (LFs) for all clusters as well as redshift-stacked and
temperature-stacked LFs in three filters, g', r' and z', down to M=-14.5. All
LFs were fitted by Schechter functions which constrained the faint-end slope,
alpha, but did not always fit well to the bright end. Derived values of alpha
ranged from -1.03 to as steep as -2.1. We find no evidence for upturns at faint
magnitudes. Evolution in alpha was apparent in all bands: it becomes shallower
with increasing redshift; for example, in the z' band it flattened from -1.75
at low redshift to -1.22 in the redshift range z=0.43-0.61. Eight of our
systems lie at z~0.3, and we combine these to generate a galaxy LF in three
colours for X-ray selected groups and poor clusters at redshift 0.3. We find
that at z~0.3 alpha is steeper (-1.67) in the green (g') band than it is
(-1.30) in the red (z') band. This colour trend disappears at low redshift,
which we attribute to reddening of faint blue galaxies from z~0.3 to z~0. We
also calculated the total optical luminosity and found it to correlate strongly
with X-ray luminosity (L_X proportional to L_OPT^(2.1)), and also with ICM
temperature (L_OPT proportional to T^(1.62)), consistent with expectations for
self-similar clusters with constant mass-to-light ratio. We did not find any
convincing correlation of Schechter parameters with mean cluster temperature.Comment: 23 pages, 17 figure
Kinome and Transcriptome Profiling Reveal Broad and Distinct Activities of Erlotinib, Sunitinib, and Sorafenib in the Mouse Heart and Suggest Cardiotoxicity From Combined Signal Transducer and Activator of Transcription and Epidermal Growth Factor Receptor Inhibition
BACKGROUND: Most novel cancer therapeutics target kinases that are essential to tumor survival. Some of these kinase inhibitors are associated with cardiotoxicity, whereas others appear to be cardiosafe. The basis for this distinction is unclear, as are the molecular effects of kinase inhibitors in the heart.
METHODS AND RESULTS: We administered clinically relevant doses of sorafenib, sunitinib (cardiotoxic multitargeted kinase inhibitors), or erlotinib (a cardiosafe epidermal growth factor receptor inhibitor) to mice daily for 2 weeks. We then compared the effects of these 3 kinase inhibitors on the cardiac transcriptome using RNAseq and the cardiac kinome using multiplexed inhibitor beads coupled with mass spectrometry. We found unexpectedly broad molecular effects of all 3 kinase inhibitors, suggesting that target kinase selectivity does not define either the molecular response or the potential for cardiotoxicity. Using in vivo drug administration and primary cardiomyocyte culture, we also show that the cardiosafety of erlotinib treatment may result from upregulation of the cardioprotective signal transducer and activator of transcription 3 pathway, as co-treatment with erlotinib and a signal transducer and activator of transcription inhibitor decreases cardiac contractile function and cardiomyocyte fatty acid oxidation.
CONCLUSIONS: Collectively our findings indicate that preclinical kinome and transcriptome profiling may predict the cardiotoxicity of novel kinase inhibitors, and suggest caution for the proposed therapeutic strategy of combined signal transducer and activator of transcription/epidermal growth factor receptor inhibition for cancer treatment
âSubmitting Love?â: a sensory sociology of Southbourne
This article seeks to remember the Southbourne building of Sheffield Hallam University, United Kingdom, which housed
students, academics, and administrative staff until August 2014. Data were collected from an ethnographic observation
study of students handing in completed coursework. Findings are presented in the form of an audio âsoundscapeâ and a literary narrative. It is argued that these hypermodal tools should form a growing part of qualitative inquiry as sensory social research. The historic application and practical impediments of such sensorial and aural techniques are discussed, alongside the challenge they provide to the received practices concerning how journal articles can be experienced
Serendipity and the SDSS: Discovery of the Largest Known Planetary Nebula on the Sky
Investigation of spectra from the Sloan Digital Sky Survey reveals the
presence of a region of ionized gas of >2 degrees diameter centered
approximately at alpha = 10^h 37^m delta = -00^o 18' (J2000) (Galactic
coordinates l=248, b=+48). [OIII] 4959,5007 emission is particularly strong and
emission from H-alpha and [NII] 6548,6583 is also detectable over a substantial
area on the sky. The combination of emission line ratios, the close to zero
heliocentric radial velocity and the morphology of the structure are consistent
with an identification as a very nearby planetary nebula. The proximity of the
hot, DO white dwarf PG1034+001 further strengthens this interpretation. The
object is: i) the largest planetary nebula on the sky, ii) certainly closer
than any planetary nebula other than Sh 2--216, iii) the first to be
unambiguously associated with a DO white dwarf. A parallax distance for
PG1034+001 would establish whether the structure is in fact the closest, and
one of the physically largest, planetary nebula known.Comment: 12 pages including 4 figures. ApJ Letters in pres
Combined analysis of weak lensing and X-ray blind surveys
We present a joint weak lensing and X-ray analysis of 4 deg from the
CFHTLS and XMM-LSS surveys. Our weak lensing analysis is the first analysis of
a real survey using shapelets, a new generation weak lensing analysis method.
We create projected mass maps of the images, and extract 6
weak-lensing-detected clusters of galaxies. We show that their counts can be
used to constrain the power spectrum normalisation for . We show that despite the large
scatter generally observed in the M-T relation derived from lensing masses,
tight constraints on both its slope and normalisation can be obtained
with a moderate number of sources provided that the covered mass range is large
enough. Adding clusters from Bardeau et al. (2007) to our sample, we measure
. Although they are
dominated by shot noise and sample variance, our measurements are consistent
with currently favoured values, and set the stage for future surveys. We thus
investigate the dependence of those estimates on survey size, depth, and
integration time, for joint weak lensing and X-ray surveys. We show that deep
surveys should be dedicated to the study of the physics of clusters and groups
of galaxies. For a given exposure time, wide surveys provide a larger number of
detected clusters and are therefore preferred for the measurement of
cosmological parameters such as and . We show that a wide
survey of a few hundred square degrees is needed to improve upon current
measurements of these parameters. More ambitious surveys covering 7000 deg
will provide the 1% accuracy in the estimation of the power spectrum and the
M-T relation normalisations.Comment: MNRAS in press Matches accepted version. References update
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