166 research outputs found

    ZFIRE: The Evolution of the Stellar Mass Tully-Fisher Relation to Redshift 2.0 < Z < 2.5 with MOSFIRE

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    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

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    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

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    We present a new rest-frame color-color selection method using "synthetic usgsu_s-g_s and gsisg_s-i_s'', (ugi)s(ugi)_s colors to identify star-forming and quiescent galaxies. Our method is similar to the widely-used UVU-V versus VJV-J (UVJUVJ) diagram. However, UVJUVJ suffers known systematics. Spectroscopic campaigns have shown that UVJUVJ-selected quiescent samples at z3z \gtrsim 3 include 1030%\sim 10-30\% contamination from galaxies with dust-obscured star formation and strong emission lines. Moreover, at z>3z>3, UVJUVJ colors are extrapolated because the rest-frame J-band shifts beyond the coverage of the deepest bandpasses at <5 μm< 5~\mu m (typically SpitzerSpitzer/IRAC 4.5 μm\mu m or future JWSTJWST/NIRCam observations). We demonstrate that (ugi)s(ugi)_s offers improvements to UVJUVJ at z>3z>3, and can be applied to galaxies in the JWSTJWST era. We apply (ugi)s(ugi)_s selection to galaxies at 0.5<z<60.5<z<6 from the (observed) 3D-HST and UltraVISTA catalogs, and to the (simulated) JAGUAR catalogs. We show that extrapolation can affect (VJ)0(V-J)_0 color by up to 1 magnitude, but changes (usis)0(u_s-i_s)_0 color by \leq 0.2 mag, even at z6z\simeq 6. While (ugi)s(ugi)_s-selected quiescent samples are comparable to UVJUVJ in completeness (both achieve \sim85-90% at z=33.5z=3-3.5), (ugi)s(ugi)_s reduces contamination in quiescent samples by nearly a factor of two, from \simeq35% to \simeq17% at z=3z=3, and from \simeq 60% to \simeq 33% at z=6z=6. This leads to improvements in the true-to-false-positive ratio (TP/FP), where we find TP/FP \gtrsim 2.2 for (ugi)s(ugi)_s at z3.56z \simeq 3.5 - 6, compared to TP/FP << 1 for UVJUVJ-selected samples. This indicates that contaminants will outnumber true quiescent galaxies in UVJUVJ at these redshifts, while (ugi)s(ugi)_s will provide higher-fidelity samples.Comment: Submitted to Ap

    Effect of local environment and stellar mass on galaxy quenching and morphology at 0.5<z<2.00.5<z<2.0

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    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, log(M/M)>9(9.5)\log(M/M_\odot)>9 (9.5) at z=1.3 (2.0). This method, when applied to a mock catalog with the photometric-redshift precision (σz/(1+z)0.02\sigma_z / (1+z) \lesssim 0.02), 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 (log(M/M)\log (M/M_\odot)\gtrsim 10.5) at all redshifts. For lower mass galaxies (log(M/M))\log (M/M)_\odot) \lesssim 10), the environmental quenching efficiency is very low at zz\gtrsim 1.5, but increases rapidly with decreasing redshift. Environmental quenching can account for nearly all quiescent lower mass galaxies (log(M/M)\log(M/M_\odot) \sim 9-10), which appear primarily at zz\lesssim 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

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    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 z\sim2, 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 z\sim3-4, 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 1.7×\times1011^{11} M_\odot 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)

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    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

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    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

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    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

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    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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