166 research outputs found
ZFIRE: The Evolution of the Stellar Mass Tully-Fisher Relation to Redshift 2.0 < Z < 2.5 with MOSFIRE
Using observations made with MOSFIRE on Keck I as part of the ZFIRE survey,
we present the stellar mass Tully-Fisher relation at 2.0 < z < 2.5. The sample
was drawn from a stellar mass limited, Ks-band selected catalog from ZFOURGE
over the CANDELS area in the COSMOS field. We model the shear of the Halpha
emission line to derive rotational velocities at 2.2X the scale radius of an
exponential disk (V2.2). We correct for the blurring effect of a
two-dimensional PSF and the fact that the MOSFIRE PSF is better approximated by
a Moffat than a Gaussian, which is more typically assumed for natural seeing.
We find for the Tully-Fisher relation at 2.0 < z < 2.5 that logV2.2 =(2.18 +/-
0.051)+(0.193 +/- 0.108)(logM/Msun - 10) and infer an evolution of the
zeropoint of Delta M/Msun = -0.25 +/- 0.16 dex or Delta M/Msun = -0.39 +/- 0.21
dex compared to z = 0 when adopting a fixed slope of 0.29 or 1/4.5,
respectively. We also derive the alternative kinematic estimator S0.5, with a
best-fit relation logS0.5 =(2.06 +/- 0.032)+(0.211 +/- 0.086)(logM/Msun - 10),
and infer an evolution of Delta M/Msun= -0.45 +/- 0.13 dex compared to z < 1.2
if we adopt a fixed slope. We investigate and review various systematics,
ranging from PSF effects, projection effects, systematics related to stellar
mass derivation, selection biases and slope. We find that discrepancies between
the various literature values are reduced when taking these into account. Our
observations correspond well with the gradual evolution predicted by
semi-analytic models.Comment: 21 pages, 14 figures, 1 appendix. Accepted for publication by Apj,
February 28, 201
Validation du Multidimensional Jealousy Scale
Bien que la jalousie soit reliée négativement au bien-être individuel et conjugal, peu d’instruments validés en langue française sont disponibles. Cet article présente la traduction du Multidimensional Jealousy Scale (Pfeiffer & Wrong, 1989) et la validation de l’Échelle multidimensionnelle de jalousie, un questionnaire évaluant les dimensions cognitive, affective et comportementale de la jalousie en 24 items. Les qualités psychométriques du questionnaire sont évaluées auprès de deux échantillons indépendants. Dans l’étude 1 (N=300), une analyse factorielle exploratoire suggère une structure tridimensionnelle du questionnaire abrégé en 15 items. La validité critériée et la fidélité (cohérence interne) sont également examinées. Dans l’étude 2 (N=381), des analyses factorielles confirmatoires appuient la structure tridimensionnelle de la version en 15 items. Ces résultats soutiennent l’utilisation de l’Échelle multidimensionnelle de jalousie en 15 items
Beyond UVJ: Color Selection of Galaxies in the JWST Era
We present a new rest-frame color-color selection method using "synthetic
and '', colors to identify star-forming and
quiescent galaxies. Our method is similar to the widely-used versus
() diagram. However, suffers known systematics. Spectroscopic
campaigns have shown that -selected quiescent samples at
include contamination from galaxies with dust-obscured star
formation and strong emission lines. Moreover, at , colors are
extrapolated because the rest-frame J-band shifts beyond the coverage of the
deepest bandpasses at (typically /IRAC 4.5 or
future /NIRCam observations). We demonstrate that offers
improvements to at , and can be applied to galaxies in the
era. We apply selection to galaxies at from the (observed)
3D-HST and UltraVISTA catalogs, and to the (simulated) JAGUAR catalogs. We show
that extrapolation can affect color by up to 1 magnitude, but changes
color by 0.2 mag, even at . While
-selected quiescent samples are comparable to in completeness
(both achieve 85-90% at ), reduces contamination in
quiescent samples by nearly a factor of two, from 35% to 17% at
, and from 60% to 33% at . This leads to
improvements in the true-to-false-positive ratio (TP/FP), where we find TP/FP
2.2 for at , compared to TP/FP 1 for
-selected samples. This indicates that contaminants will outnumber true
quiescent galaxies in at these redshifts, while will provide
higher-fidelity samples.Comment: Submitted to Ap
Effect of local environment and stellar mass on galaxy quenching and morphology at
We study galactic star-formation activity as a function of environment and
stellar mass over 0.5<z<2.0 using the FourStar Galaxy Evolution (ZFOURGE)
survey. We estimate the galaxy environment using a Bayesian-motivated measure
of the distance to the third nearest neighbor for galaxies to the stellar mass
completeness of our survey, at z=1.3 (2.0). This
method, when applied to a mock catalog with the photometric-redshift precision
(), recovers galaxies in low- and high-density
environments accurately. We quantify the environmental quenching efficiency,
and show that at z> 0.5 it depends on galaxy stellar mass, demonstrating that
the effects of quenching related to (stellar) mass and environment are not
separable. In high-density environments, the mass and environmental quenching
efficiencies are comparable for massive galaxies (
10.5) at all redshifts. For lower mass galaxies (
10), the environmental quenching efficiency is very low at 1.5, but
increases rapidly with decreasing redshift. Environmental quenching can account
for nearly all quiescent lower mass galaxies ( 9-10),
which appear primarily at 1.0. The morphologies of lower mass
quiescent galaxies are inconsistent with those expected of recently quenched
star-forming galaxies. Some environmental process must transform the
morphologies on similar timescales as the environmental quenching itself. The
evolution of the environmental quenching favors models that combine gas
starvation (as galaxies become satellites) with gas exhaustion through
star-formation and outflows ("overconsumption"), and additional processes such
as galaxy interactions, tidal stripping and disk fading to account for the
morphological differences between the quiescent and star-forming galaxy
populations.Comment: 29 pages, 15 figure, accepted for publication in Ap
A massive, quiescent galaxy at redshift of z=3.717
In the early Universe finding massive galaxies that have stopped forming
stars present an observational challenge as their rest-frame ultraviolet
emission is negligible and they can only be reliably identified by extremely
deep near-infrared surveys. These have revealed the presence of massive,
quiescent early-type galaxies appearing in the universe as early as z2,
an epoch 3 Gyr after the Big Bang. Their age and formation processes have now
been explained by an improved generation of galaxy formation models where they
form rapidly at z3-4, consistent with the typical masses and ages derived
from their observations. Deeper surveys have now reported evidence for
populations of massive, quiescent galaxies at even higher redshifts and earlier
times, however the evidence for their existence, and redshift, has relied
entirely on coarsely sampled photometry. These early massive, quiescent
galaxies are not predicted by the latest generation of theoretical models.
Here, we report the spectroscopic confirmation of one of these galaxies at
redshift z=3.717 with a stellar mass of 1.710 M whose
absorption line spectrum shows no current star-formation and which has a
derived age of nearly half the age of the Universe at this redshift. The
observations demonstrates that the galaxy must have quickly formed the majority
of its stars within the first billion years of cosmic history in an extreme and
short starburst. This ancestral event is similar to those starting to be found
by sub-mm wavelength surveys pointing to a possible connection between these
two populations. Early formation of such massive systems is likely to require
significant revisions to our picture of early galaxy assembly.Comment: 6 pages, 7 figures. This is the final preprint corresponding closely
to the published version. Uploaded 6 months after publication in accordance
with Nature polic
CRH – Études sociales et politiques des populations, de la protection sociale et de la santé (ESOPP)
Patrice Bourdelais, Laura Lee Downs, Geneviève Massard-Guilbaud, Paul-André Rosental, directeurs d’étudesYohann Aucante, Antoinette Fauve-Chamoux, Morgane Labbé,maîtres de conférencesCaroline Douki, maître de conférences à l’Université Paris VIIIHélène Frouard, chercheuse post-doctorante à l’Université Paris-IBernard Thomann, maître de conférences à l’INaLCO L’auto-fabrication des sociétés : population, politiques sociales, santé Ce séminaire collectif présente les travaux et les problématiqu..
Histoire sociale et politique des populations
Paul-André Rosental, directeur d’études Population, migrations et histoire politique Le séminaire s’est concentré sur l’histoire de la silicose en France au XXe siècle, et sur les problèmes démographiques, sanitaires et sociaux liés à sa reconnaissance et à sa réparation. L’histoire du traitement officiel de la silicose commence en France par une reconnaissance médicale et légale péniblement négociée, de la fin des années 1920 à la Libération. Sa nosologie et son étiologie complexes, son appa..
Histoire sociale et politique des populations
Paul-André Rosental, directeur d’études Population, migrations et histoire politique Le séminaire s’est concentré sur l’histoire de la silicose en France au XXe siècle, et sur les problèmes démographiques, sanitaires et sociaux liés à sa reconnaissance et à sa réparation. L’histoire du traitement officiel de la silicose commence en France par une reconnaissance médicale et légale péniblement négociée, de la fin des années 1920 à la Libération. Sa nosologie et son étiologie complexes, son appa..
Histoire sociale et politique des populations
Paul-André Rosental, directeur d’études Population et histoire politique L’entre-deux-guerres constitue une période stratégique pour l’historiogra-phie des migrations. C’est à cette époque que se forge le modèle push and pull, qui explique les flux migratoires par les fluctuations de la conjoncture économique aux points de départ et d’arrivée. Ce modèle, dont la pertinence a souvent été relativisée par les sciences sociales, conditionne toujours la perception du phénomène par les organismes n..
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