686 research outputs found
EROs found behind lensing clusters: II.Empirical properties, classification, and SED modelling based on multi-wavelength observations
We study the properties and nature of extremely red galaxies (ERO, R-K>5.6)
found behind two lensing clusters and compare them with other known galaxy
populations. New HST/ACS observations, Spitzer IRAC and MIPS, and Chandra/ACIS
observations of the two lensing clusters Abell 1835 and AC114 contemplate our
earlier optical and near-IR observations and have been used to study extremely
red objects (EROs) in these deep fields. We have found 6 and 9 EROs in Abell
1835 and AC114. Several (7) of these objects are undetected up to the I and/or
z band, and are hence ``optical'' drop-out sources. The photometric redshifts
of most of our sources (80%) are z~0.7-1.5. According to simple colour-colour
diagrams the majority of our objects would be classified as hosting old stellar
populations. However, there are clear signs of dusty starbursts for several
among them. These objects correspond to the most extreme ones in R-K colour. We
estimate a surface density of (0.97+-0.31) arcmin-2 for EROs with (R-K>5.6) at
K<20.5. Among our 15 EROs 6 (40 %) also classify as distant red galaxies
(DRGs). 11 of 13 EROs with available IRAC photometry also fulfil the selection
criteria for IRAC selected EROs (IEROs) of Yan et al. (2004). SED modelling
shows that ~ 36 % of the IEROs in our sample are luminous or ultra-luminous
infrared galaxies ((U)LIRG). Some very red DRGs are found to be very dusty
starbursts, even (U)LIRGs, as also supported by their mid-IR photometry. No
indication for AGNs is found, although faint activity cannot be excluded for
all objects. From mid-IR and X-ray data 5 objects are clearly classified as
starbursts. The derived properties are quite similar to those of DRGs and
IEROs, except for 5 extreme objects in terms of colours, for which a very high
extinction (Av>3) is found.Comment: 20 pages, 10 figures, accepted for publication in A&
A peculiar galaxy appears at redshift 11: properties of a moderate redshift interloper
Laporte et al. (2011) reported a very high redshift galaxy candidate: a
lensed J-band dropout (A2667-J1). J1 has a photometric redshift of z=9.6-12,
the probability density function for which permits no low or intermediate z
solution. We here report new spectroscopic observations of this galaxy with
VLT/XShooter, which show clear [OIII]5007AA, Ly-alpha, H-alpha, and H-beta
emission and place the galaxy firmly at z=2.082. The oxygen lines contribute
only ~25% to the H-band flux, and do not significantly affect the dropout
selection of J1. After correcting the broadband fluxes for line emission, we
identify two roughly equally plausible natures for A2667-J1: either it is young
heavily reddened starburst, or a maximally old system with a very pronounced
4000AA break, upon which a minor secondary burst of star formation is
superimposed. Fits show that to make a 3 sigma detection of this object in the
B-band (V-band), imaging of depth AB=30.2 (29.5) would be required - despite
the relatively bright NIR magnitude, we would need optical data of equivalent
depth to the Hubble Ultra Deep Field to rule out the mid-z solution on purely
photometric grounds. Assuming that this stellar population can be scaled to the
NIR magnitudes of recent HST/WFC3 IR-selected galaxies, we conclude that
infeasibly deep optical data AB~32 would be required for the same level of
security. There is a population of galaxies at z~2 with continuum colours alone
that mimic those of our z=7-12 candidates.Comment: Accepted by Monthly Notices. 5 pages, 2 figure
News from z~6-10 galaxy candidates found behind gravitational lensing clusters
We summarise the current status of our project to identify and study z~6-10 galaxies thanks to strong gravitational lensing. Building on the detailed work from Richard et al. (2006), we present results from new follow-up observations (imaging) undertaken with ACS/HST and the Spitzer Space Telescope and compare our results with findings from the Hubble Ultra-Deep Field (UDF). These new observations are in agreement with the high-z nature for the vast majority of the candidates presented in Richard et al. (2006). We also discuss the properties of other optical dropout sources found in our searches and related objects (EROs, sub-mm galaxies,...) from other surveys
Neighborhood fast food restaurants and fast food consumption: A national study
<p>Abstract</p> <p>Background</p> <p>Recent studies suggest that neighborhood fast food restaurant availability is related to greater obesity, yet few studies have investigated whether neighborhood fast food restaurant availability promotes fast food consumption. Our aim was to estimate the effect of neighborhood fast food availability on frequency of fast food consumption in a national sample of young adults, a population at high risk for obesity.</p> <p>Methods</p> <p>We used national data from U.S. young adults enrolled in wave III (2001-02; ages 18-28) of the National Longitudinal Study of Adolescent Health (n = 13,150). Urbanicity-stratified multivariate negative binomial regression models were used to examine cross-sectional associations between neighborhood fast food availability and individual-level self-reported fast food consumption frequency, controlling for individual and neighborhood characteristics.</p> <p>Results</p> <p>In adjusted analysis, fast food availability was not associated with weekly frequency of fast food consumption in non-urban or low- or high-density urban areas.</p> <p>Conclusions</p> <p>Policies aiming to reduce neighborhood availability as a means to reduce fast food consumption among young adults may be unsuccessful. Consideration of fast food outlets near school or workplace locations, factors specific to more or less urban settings, and the role of individual lifestyle attitudes and preferences are needed in future research.</p
Planck's Dusty GEMS: Gravitationally lensed high-redshift galaxies discovered with the Planck survey
We present an analysis of 11 bright far-IR/submm sources discovered through a
combination of the Planck survey and follow-up Herschel-SPIRE imaging. Each
source has a redshift z=2.2-3.6 obtained through a blind redshift search with
EMIR at the IRAM 30-m telescope. Interferometry obtained at IRAM and the SMA,
and optical/near-infrared imaging obtained at the CFHT and the VLT reveal
morphologies consistent with strongly gravitationally lensed sources.
Additional photometry was obtained with JCMT/SCUBA-2 and IRAM/GISMO at 850 um
and 2 mm, respectively. All objects are bright, isolated point sources in the
18 arcsec beam of SPIRE at 250 um, with spectral energy distributions peaking
either near the 350 um or the 500 um bands of SPIRE, and with apparent
far-infrared luminosities of up to 3x10^14 L_sun. Their morphologies and sizes,
CO line widths and luminosities, dust temperatures, and far-infrared
luminosities provide additional empirical evidence that these are strongly
gravitationally lensed high-redshift galaxies. We discuss their dust masses and
temperatures, and use additional WISE 22-um photometry and template fitting to
rule out a significant contribution of AGN heating to the total infrared
luminosity. Six sources are detected in FIRST at 1.4 GHz. Four have flux
densities brighter than expected from the local far-infrared-radio correlation,
but in the range previously found for high-z submm galaxies, one has a deficit
of FIR emission, and 6 are consistent with the local correlation. The global
dust-to-gas ratios and star-formation efficiencies of our sources are
predominantly in the range expected from massive, metal-rich, intense,
high-redshift starbursts. An extensive multi-wavelength follow-up programme is
being carried out to further characterize these sources and the intense
star-formation within them.Comment: A&A accepte
The SAFRAN-ISBA-MODCOU hydrometeorological model applied over France
An edited version of this paper was published by AGU. Copyright (2008) American Geophysical UnionThe hydrometeorological model SIM consists in a meterological analysis system (SAFRAN), a land surface model (ISBA) and a hydrogeological model (MODCOU). It generates atmospheric forcing at an hourly time step, and it computes water and surface energy budgets, the river ow at more than 900 rivergauging stations, and the level of several aquifers. SIM was extended over all of France in order to have a homogeneous nation-wide monitoring of the water resources: it can therefore be used to forecast flood risk and to monitor drought risk over the entire nation. The hydrometeorologival model was applied over a 10-year period from 1995 to 2005. In this paper the databases used by the SIM model are presented, then the 10-year simulation is assessed by using the observations of daily stream-flow, piezometric head, and snow depth. This assessment shows that SIM is able to reproduce the spatial and temporal variabilities of the water fluxes. The efficiency is above 0.55 (reasonable results) for 66 % of the simulated rivergages, and above 0.65 (rather good results) for 36 % of them. However, the SIM system produces worse results during the driest years, which is more likely due to the fact that only few aquifers are simulated explicitly. The annual evolution of the snow depth is well reproduced, with a square correlation coeficient around 0.9 over the large altitude range in the domain. The stream ow observations were used to estimate the overall error of the simulated latent heat ux, which was estimated to be less than 4 %
The bright-end of the luminosity function at z~9
We report new constraints on the galaxy luminosity function at z~9 based on
observations carried out with ESO/VLT FORS2, HAWK-I and X-Shooter around the
lensing cluster A2667, as part of our project aimed at selecting z~7-10
candidates accessible to spectroscopy. Only one J-dropout source was selected
in this field fulfilling the color and magnitude criteria. This source was
recently confirmed as a mid-z interloper based on X-Shooter spectroscopy. The
depth and the area covered by our survey are well suited to set strong
constraints on the bright-end of the galaxy luminosity function and hence on
the star formation history at very high redshift. The non-detection of reliable
J-dropout sources over the ~36arcmin2 field of view towards A2667 was used to
carefully determine the lens-corrected effective volume and the corresponding
upper-limit on the density of sources. The strongest limit is obtained for
Phi(M_{1500}=-21.4+/-0.50)<6.70x10^{-6}Mpc^{-3}mag^{-1} at z~9. A
maximum-likelihood fit of the luminosity function using all available data
points including the present new result yields M*>-19.7 with fixed alpha=-1.74
and Phi*=1.10x10^{-3}Mpc^{-3}. The corresponding star formation rate density
should be rho_{SFR}<5.97x10^{-3}M_{solar}/yr/Mpc^{3} at z~9. These results are
in good agreement with the most recent estimates already published in this
range of redshift and for this luminosity domain. This new result confirms the
decrease in the density of luminous galaxies at very high-redshift, hence
providing strong constraints for the design of future surveys aiming to explore
the very high-redshift Universe.Comment: 4 pages, 2 figures, accepted for publication in A&A Letter
Complementary and alternative medicine use in glioma patients in France
PURPOSE
Complementary and alternative medicine (CAM) use increases in cancer patients, including adult patients with diffuse gliomas.
METHODS
Questionnaires addressing CAM use were distributed to adult patients with gliomas of WHO grades II-IV and ECOG performance score of 0-2 during hospital visits and filled in anonymously. The study was conducted in nine centers in France from May 2017 to May 2018. Descriptive cohort analyses and comparative analyses according to gender, age, WHO grade, and recurrent versus newly diagnosed disease were conducted.
RESULTS
Two hundred twenty-seven questionnaires were collected; 135 patients (59%) were male. Median age was 48 years, 105 patients (46%) declared having glioblastoma, 99 patients (43%) declared having recurrent disease. Hundred-three patients (45%) had modified their alimentary habits after the glioma diagnosis. At the time of the questionnaire, 100 patients (44%) were on complementary treatment, mainly vitamins and food supplements, and 73 patients (32%) used alternative medicine approaches, mainly magnetism and acupuncture. In total, 154 patients (68%) declared using at least one of these approaches. Expenditures exceeding 100 ⏠per month were reported by users in 14% for modification of alimentary habits, in 25% for complementary treatment, and in 18% for alternative medicines. All approaches were commonly considered as improving quality of life and experienced as efficient, notably those associated with more expenditures.
CONCLUSIONS
CAM are frequently used by glioma patients in France. Underlying needs and expectations, as well as potential interactions with tumor-specific treatments, and financial and quality of life burden, should be discussed with patients and caregivers
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