VIIth Marseille International Cosmology Conference : Dynamics and mass assembly of 1
Thierry Contini, and the MASSIV collaboration (www.ast.obs-mip.fr/massiv)
Abstract: A key question in the formation and evolution of galaxies is the epoch and mechanisms of mass assembly. I will present the first results of MASSIV (Mass Assembly Survey with SINFONI in VVDS), an on-going ESO Large Program, using the AO-assisted NIR 3D spectrograph SINFONI on VLT, aiming to measure the velocity field of a unique sample of ~100 star-forming galaxies in the redshift range 1-2 selected in the VIMOS VLT Deep Survey. This large sample, spanning a wide range of masses (logM=[9-12]), is statistically representative of the overall population and thus suitable to probe the evolution in masses, mass-to-light ratios, and metallicities of these galaxies, as well as the fraction of mass ...
Durée: 17:43 mn Date: 04 2010
2
VIIth Marseille International Cosmology Conference : The Gemini view of the redshift desert: nuggets & novelties.
Karl Glazebrook (Swinburne University of Technology)
Abstract: the latest observations and interpretations of compact red galaxies discovered at 1<2 using Gemini and HST.OAMP
Durée: 27:08 mn
Date: 03 2010
2
VIIth Marseille International Cosmology Conference : Galaxy caracterization
Naveen Reddy (Hubble Fellow, NOAO) The conference is devoted to the last results from observational and theoretical programs studying the Universe between redshifts 1 and 3, the so called redshift desert. During this more than 3.5 Gyr long period, the first massive structures condensed, and part of the massive galaxies formed through merging processes. The QSO Luminosity fonction peaked in intensity, allowing to study in detail the IGM physics. A new generation of large observational programs proposes as well to investigate the fundamental cosmology in this period. We propose to browse all these subjects, with reviews, invited talks, and shorter contributions.
Durée: 35:27 mn Date: 03 2010
2
VIIth Marseille International Cosmology Conference : A major spectrocopic campaign targeting K-band selected galaxies in the UKIDSS Ultra-deep Survey A backward evolution model for infrared surveys: the role of AGN- and Color-L_TIR distributions
Elisabetta Valiante ( UBC - Dpt of Physics and Astr. )
Empirical 'backward' galaxy evolution models for infrared bright galaxies are constrained using multi-band infrared surveys. I developed a new Monte-Carlo algorithm for this task, implementing luminosity dependent distribution functions for the galaxies' infrared SED and for the AGN contribution, allowing for evolution of these quantities. A local infrared luminosity function is adopted and evolved using power law parametrizations for possible luminosity and density evolutions. The adopted SEDs take into account the contributions of both starburst and AGN to the total infrared luminosity, for the first time in a coherent treatment rather than separate AGN and star-forming populations. The ...
Durée: 16:33 mn Date: 03 2010
2
VIIth Marseille International Cosmology Conference : Probing the Limits of Nuclear Activity in the Redshift Desert
Chris Impey (Steward Observatory, University of Arizona)
The Cosmological Evolution Survey (COSMOS) is centered on the largest contiguous region of the sky ever imaged by HST. It was motivated by the study of galaxy evolution and morphology but the combination of depth, breadth and extensive multiwavelength data makes it the best region in the sky for a comprehensive study of the coevolution of AGN and galaxies. This contribution will concentrate on the properties of ~300 Type 1 AGN selected by X-ray emission, where obscured and rare populations can be recovered using bolometric selection and where the sensitivity reaches black hole masses below 10^8 and accretion rates below 0.01 L_edd through the redshift desert from 1 < z < 3.
Durée: 19:26 mn Date: 03 2010
2
VIIth Marseille International Cosmology Conference : QSO Built up
Gordon Richards (Drexel University) The conference is devoted to the last results from observational and theoretical programs studying the Universe between redshifts 1 and 3, the so called redshift desert. During this more than 3.5 Gyr long period, the first massive structures condensed, and part of the massive galaxies formed through merging processes. The QSO Luminosity fonction peaked in intensity, allowing to study in detail the IGM physics. A new generation of large observational programs proposes as well to investigate the fundamental cosmology in this period. We propose to browse all these subjects, with reviews, invited talks, and shorter contributions.
Durée: 28:32 mn Date: 03 2010
2
VIIth Marseille International Cosmology Conference : Evolution of the color magnitude relation and galaxy properties in clusters and groups at z~1
Simona Mei (Paris Observatory)
We applied detailed observations of the Color-Magnitude Relation (CMR) with the ACS/HST to study galaxy evolution in eight clusters at z~1 (ACS GTO Intermediate Redshift Cluster survey; Mei et al. 2008). The early-type red sequence is well defined and elliptical and lenticular galaxies lie on similar CMRs. We analyzed CMR parameters - scatter, slope and zero-point - as a function of redshift, galaxy properties and cluster mass. While the bright S0 population consistently shows larger scatter than the ellipticals, the scatter of the latter increases in the peripheral cluster regions. We interpret these results in terms of galaxy age differences. We also analyzed the morphological fractions of red sequence galaxies. We find that, while in ...
Durée: 15:45 mn Date: 03 2010
2
VIIth Marseille International Cosmology Conference : Kiloparsec-Scale Kinematics in High Red shift Star-Forming Galaxies
David R. Law (UCLA)
I discuss the results of a multi-year Keck/LGSAO survey of the internal kinematics of rapidly star-forming galaxies at redshift z ~ 2 - 3 as traced by nebular line emission on angular scales ~ 0.1''. At most 5 of the 13 best-detected galaxies have spatially resolved velocity gradients consistent with rotation, while the remaining galaxies have relatively featureless or irregular velocity fields. All of our galaxies exhibit high local velocity dispersions ~ 60 - 100 km/s, suggesting that even for those galaxies with clear velocity gradients rotation about a preferred kinematic axis may not be the dominant means of physical support. The dynamical importance of cold gas appears to be the primary factor governing the observed ...
Durée: 6:27 mn Date: 03 2010
2
VIIth Marseille International Cosmology Conference : Suerdense massive galaxies : sizes and evolution since z - 3
Alonso Fernando Buitrago ( Univ. Nottingham)
Understanding the evolutionary pathway of massive galaxies (M ≥ 1011 M⊙) is one of the greatest challenges of the present day Astronomy. To address this problem our group carried out using the HST NICMOS 3 camera the GOODS NICMOS Survey which provides us with extremely deep (H ∼26.8) imaging of 81 these galaxies at 1.7 < z < 3. Our sample is almost one order of magnitude larger than previous studies, and is the first statistical study of massive galaxies at these redshifts. The results (split between spheroid and disk like ob jects according to their S´ersic index) show that these massive galaxies are extraordinarily compact, reaching densities comparable ...
Durée: 16:48 mn Date: 03 2010
2
VIIth Marseille International Cosmology Conference : Size evolution of early-type galaxies
Arjen van der Wel (Max-Planck-Institute for Astronomy, Heidelberg)
Abstract:
Several studies have revealed the presence of high-redshift (z~2) galaxies that are much like present-day early-type galaxies: they are compact, their star-formation rates are low, and they have evolved stellar populations. The main difference between these objects and equally massive local counterparts is that their sizes are 3-5 times smaller. The need to understand how these galaxies evolved between z~2 and the present goes beyond the need to satisfy our curiosity regarding the fate of these intriguing objects: their evolution must be intimately related to galaxy assembly over cosmic time in general. First I will summarize the observational evidence for strong size evolution of early-type ...
Durée: 20:40 mn Date: 03 2010
2
VIIth Marseille International Cosmology Conference : Weak velocity dispersion evolution of spheroid-like massive galaxies since z-2
Nacho Trujillo (IAC)
Abstract: Massive galaxies (M~10^11 Msun) at z>1.5 were structurally very different than their equally massive local counterparts. These galaxies were extremely compact, with effective radii <1.5 kpc and stellar densities as high as those that can be found in present-day globular clusters. In this contribution I will summarize the recent results that our group has found in relation to the evolution of these primordial objects. I will particularly focus on the first determination of the velocity dispersion of such galaxies at z~1.6 based on an averaged spectra with a total integration of 480 hours in the VLT. By comparing with galaxies of similar stellar mass at lower redshifts, we find evidence for a weak evolution in velocity ...
Durée: 17:55 mn Date: 03 2010
2
VIIth Marseille International Cosmology Conference : Dynamics and Morphologies of z - 2 Star-forming Galaxies
N. M. Förster Schreiber (MPE) The conference is devoted to the last results from observational and theoretical programs studying the Universe between redshifts 1 and 3, the so called redshift desert. During this more than 3.5 Gyr long period, the first massive structures condensed, and part of the massive galaxies formed through merging processes. The QSO Luminosity fonction peaked in intensity, allowing to study in detail the IGM physics. A new generation of large observational programs proposes as well to investigate the fundamental cosmology in this period. We propose to browse all these subjects, with reviews, invited talks, and shorter contributions.
Durée: 40:59 mn Date: 03 2010
2
VIIth Marseille International Cosmology Conference : A major spectrocopic campaign targeting K-band selected galaxies in the UKIDSS Ultra-deep Survey
Henry Pearce ( Institute for Astronomy, University of Edinburgh)
Co-Authors: H. Pearce, R. McLure, M. Cirasuolo, O. Almaini
The UKIDSS Ultra-deep survey (UDS) is currently the deepest, wide-area, near-IR imaging survey in existence. The combination of deep near-IR data with optical imaging from Subaru and deep IRAC+MIPS imaging from Spitzer makes the UDS an ideal laboratory for studying the high-redshift evolution of massive galaxies. At present, the UDS data-set is being greatly enhanced by the addition of a large VIMOS+FORS2 spectroscopic follow-up campaign on the VLT, designed to provide redshifts for >4000 K-band selected galaxies at z>1. Here we present the first results from the on-going FORS2 spectroscopy campaign which has already provided robust ...
Durée: 09:38 mn Date: 03 2010
2
VIIth Marseille International Cosmology Conference : The Stellar mass assembly type out to z=2 from the S-COSMOS survey
Olivier Ilbert (LAM)
How, when and at which rate, the different galaxy types assemble their stellar populations ? I will characterize the stellar mass assembly by type using the 2-deg2 S-COSMOS survey. Our study is based on 192,000 near-infrared selected galaxies with 1-2% accurate photometric redshifts computed with 30 deep bands. Using very deep SPITZER data, we trace the stellar mass evolution out to z=2. We split the sample in quiescent and star-forming galaxies based on a color-color criteria efficient to separate dusty star-forming and quiescent galaxies. I will show that the evolution of the quiescent and star-forming galaxies is strongly dependent on the considered stellar mass. We obtain that the most massive galaxies are already in place at z=1 while we observe ...
Durée: 15:11 mn Date: 03 2010
2
VIIth Marseille International Cosmology Conference : Probling Stellar Populations and Structural Evolution out to the densest environments at z-1.3: Star formation histories and sizes of massive aerly type galaxies in field, groups and clusters
Alessandro Rettura ( John Hopkins University - ACS Team) The conference is devoted to the last results from observational and theoretical programs studying the Universe between redshifts 1 and 3, the so called redshift desert. During this more than 3.5 Gyr long period, the first massive structures condensed, and part of the massive galaxies formed through merging processes. The QSO Luminosity fonction peaked in intensity, allowing to study in detail the IGM physics. A new generation of large observational programs proposes as well to investigate the fundamental cosmology in this period. We propose to browse all these subjects, with reviews, invited talks, and shorter contributions.
Durée: 15:34 mn Date: 03 2010
2
VIIth Marseille International Cosmology Conference : The strongly-clustered population of red galaxies at z-2
Ryan Quadri (Leiden)
Recent surveys have made it possible to perform very precise measurements of the clustering of a diverse set of nearby galaxies. Reliable measurements have been made up to z~1, where highly complete spectroscopic samples are available. The ability to successfully model these observations using simple prescriptions for the expected galaxy clustering in the LCDM framework represents a significant triumph, from an observational as well as a theoretical perspective. However, as we push the observations to higher redshift, the situation becomes less clear. It is now becoming possible to measure the clustering of a variety of galaxy types at z~1-3 with good precision. I will present results for the strongly-clustered massive red ...
Durée: 14:09 mn
Date: 03 2010
2
VIIth Marseille International Cosmology Conference : How do galaxies accrete their mass? Quiescent and star-forming massive galaxies at high redshift
Adriano Fontana (Osservatorio Astronomico di Roma)
The conference is devoted to the last results from observational and theoretical programs studying the Universe between redshifts 1 and 3, the so called redshift desert. During this more than 3.5 Gyr long period, the first massive structures condensed, and part of the massive galaxies formed through merging processes. The QSO Luminosity fonction peaked in intensity, allowing to study in detail the IGM physics. A new generation of large observational programs proposes as well to investigate the fundamental cosmology in this period. We propose to browse all these subjects, with reviews, invited talks, and shorter contributions.
Durée: 22:01 mn Date: 03 2010
2
VIIth Marseille International Cosmology Conference : A major spectrocopic campaign targeting K-band selected galaxies in the UKIDSS Ultra-deep SurveyEvolution of the merger rate from spectroscopically confirmed galaxy pairs since z-2
Loic de Ravel (LAM) & the VVDS team
The conference is devoted to the last results from observational and theoretical programs studying the Universe between redshifts 1 and 3, the so called redshift desert. During this more than 3.5 Gyr long period, the first massive structures condensed, and part of the massive galaxies formed through merging processes. The QSO Luminosity fonction peaked in intensity, allowing to study in detail the IGM physics. A new generation of large observational programs proposes as well to investigate the fundamental cosmology in this period. We propose to browse all these subjects, with reviews, invited talks, and shorter contributions.
Durée: 14:45 mn Date: 03 2010
2
VIIth Marseille International Cosmology Conference : The Evolution of the Stellar Mass Function of Galaxies from z=4 and the First Comprehensive Analysis of its Uncertainties: Evidence for Mass-Dependent Evolution
Danilo Marchesini (Yale)
Abstract : I present the evolution of the stellar mass function (SMF) of galaxies from z=4.0 to z=1.3 measured from a sample constructed from the deep NIR MUSYC, the FIRES, and the GOODS-CDFS surveys, all having very high-quality optical to mid-infrared data. I provide, for the first time, a comprehensive analysis of random and systematic uncertainties affecting the derived SMFs. I find that the mass density evolves by a factor of ~17 since z=4.0, and a factor of ~4 from z=1.3. The evolution appears to be mostly driven by a change in the normalization Phi*, but I also find evidence for evolution in the shape of the SMF, with the low-mass end evolving more rapidly than the high-mass end. Taking these results at face value, I find that they are in ...
Durée: 16:35 mn
Date: 03 2010
2
VIIth Marseille International Cosmology Conference : The many Manifestation of Downsizing: Hierarchical Galaxy Formation Models confront Observations
Fabio Fontanot (INAF-OATs)
Several observations suggest that galaxy evolution follows a different trend with respect to the bottom-up assembly of Dark Matter structures. In this talk we discuss several observed trends for which the word ``downsizing'' (DS) has been used, and in particular the evolution with redshift of stellar mass (i.e. more massive galaxies assemble earlier than low-mass counterparts), of the star formation rate (i.e. the mass of typical star-forming galaxies declines with decreasing redshift) and the ``archaeological'' DS (i.e. more massive galaxies host the older stellar populations). We compare available data-sets in the redshift range 0 < z < 4, with the predictions of three different semi-analytical models of galaxy formation within the LCDM ...
Durée: 12:32 mn
Date: 03 2010
2
VIIth Marseille International Cosmology Conference : The relative contribution of environment and stellar mass in shaping galaxies
Lidia Tasca & zCosmos Team
The conference is devoted to the last results from observational and theoretical programs studying the Universe between redshifts 1 and 3, the so called redshift desert. During this more than 3.5 Gyr long period, the first massive structures condensed, and part of the massive galaxies formed through merging processes. The QSO Luminosity fonction peaked in intensity, allowing to study in detail the IGM physics. A new generation of large observational programs proposes as well to investigate the fundamental cosmology in this period. We propose to browse all these subjects, with reviews, invited talks, and shorter contributions.
Durée: 18:32 mn Date: 03 2010
2
VIIth Marseille International Cosmology Conference : Theoretical view : Formation of massive galaxies
Gabriella De Lucia (INAF - Astronomical Observatory of Trieste)
The conference is devoted to the last results from observational and theoretical programs studying the Universe between redshifts 1 and 3, the so called redshift desert. During this more than 3.5 Gyr long period, the first massive structures condensed, and part of the massive galaxies formed through merging processes. The QSO Luminosity fonction peaked in intensity, allowing to study in detail the IGM physics. A new generation of large observational programs proposes as well to investigate the fundamental cosmology in this period. We propose to browse all these subjects, with reviews, invited talks, and shorter contributions.
Durée: 31:11 mn Date: 03 2010
2
VIIth Marseille International Cosmology Conference : Galaxy clusters at Z>1
Masayuki Tanaka (ESO)
We discuss properties of galaxies in clusters at z>1 based on three different data sets.
First, we present detailed spectral analyses of galaxies in the large-scale structures around the RDCSJ1252 cluster
at z=1.24. We spectroscopically confirm prominent structures around such a high redshift clusters for the first time.
We then look into spectral properties of galaxies and find that
(1) there are some dusty star forming galaxies in groups and field, but the cluster hosts no such galaxies and
(2) group galaxies show systematically weaker Hd absorptions compared to field galaxies.
The groups are the environment in which we observe the on-going build-up of the red sequence and we suggest that galaxy-galaxy ...
Durée: 13:15 mn
Date: 03 2010
2
VIIth Marseille International Cosmology Conference : Cluster galaxy populations 9 billion years ago
Veronica Strazzullo (NRAO)
Galaxy clusters beyond redshift one give us the chance to study environmental effects early on in cosmic times, allowing us to track galaxy evolution in overdense environments over more than 8 billion years.
I will present results from a study of galaxy populations in the X-ray luminous cluster XMMU J2235-2557 at z~1.4, among the most distant clusters discovered to date, and the most massive known at redshift z>1. An extensive high-quality multiwavelength dataset and a spectroscopic sample of 26 cluster members allow us to study luminosity functions, red sequence, and spectral energy distributions, for a sample of cluster galaxies living in an unusually overdense region in the 5Gyr old Universe.
Durée: 11:59 mn Date: 03 2010
2
VIIth Marseille International Cosmology Conference : The role of group environment in the morphological transformation of galaxies
Katarina Kovac (ETH Zurich)
Katarina Kovac and the zCOSMOS collaboration
We study the evolution of the morphological properties of galaxies residing in group environments using the data from the zCOSMOS-bright survey. The fraction of early-type galaxies in groups selected from the luminosity complete samples is constantly increasing from redshift 1 to the present, while for the mass complete samples, this holds up only for galaxies of lower masses (log(Mstellar/Msol) < 11). At a given redshift, the fraction of early type galaxies in the groups is higher than in the field and the fraction of early type isolated galaxies is ...
Durée: 17:41 mn
Date: 03 2010
2
VIIth Marseille International Cosmology Conference : The VIRMOS-VLT Deep Survey: the large scale structure emerging from the redshift desert
Agnieszka Pollo (Institute for Nuclear Research, Warsaw/Jagiellonian University, Cracow)
The VIRMOS-VLT Deep Survey (VVDS) has been a milestone in our understanding of the state of the large scale structure of the Universe back to z~2. We plan to discuss the evolution of clustering of galaxies seen by the VVDS. We investigate the evolution of the projected two-point correlation function for the global galaxy population and for particular galaxy classes, with different intrinsic luminosities, spectral types, colors and other properties. Particularly interesting is e.g. the difference between the clustering of the brightest galaxies (with L>L*) now and in the past; the shape of their correlation function deviated from the power-law much more strongly at z~1 than it is ...
Durée: 19:48 mn
Date: 03 2010
2
VIIth Marseille International Cosmology Conference : Large Scale Structures in the GOODS-SOUTH Field up to z - 2.5
Marco Castellano (INAF - Osservatorio Astronomico di Roma)
We use the deep multi–wavelength GOODS-MUSIC catalogue, provided with accurate photometric redshifts, to compute an adaptive estimate of the 3D density field, through a specifically developed algorithm, in the redshift range 0.4<2.5.
We find several high density peaks embedded in larger structures up to z~2.3. We analyse their physical properties (mass profile, M200, \sigma_v, L_X, U − B vs. B diagram), and derive that most of them are groups of galaxies, while two (at z~0.7 and z~1.6) are poor clusters with masses of few times 10^14Msun. These two clusters have an X-ray emission (Chandra 2Ms data), significantly lower than expected from their optical properties, suggesting that the two ...
Durée: 14:24 mn
Date: 03 2010
2
VIIth Marseille International Cosmology Conference : Lya forest simul vs observations
Martin Haehnelt (IOA University of Cambridge)
The conference is devoted to the last results from observational and theoretical programs studying the Universe between redshifts 1 and 3, the so called redshift desert. During this more than 3.5 Gyr long period, the first massive structures condensed, and part of the massive galaxies formed through merging processes. The QSO Luminosity fonction peaked in intensity, allowing to study in detail the IGM physics. A new generation of large observational programs proposes as well to investigate the fundamental cosmology in this period. We propose to browse all these subjects, with reviews, invited talks, and shorter contributions.
Durée: 36:12 mn Date: 03 2010
2
VIIth Marseille International Cosmology Conference : Evolution of large scale structures and theoretical expectations
Risa Wechsler (SLAC National Accelerator Laboratory)
KIPAC / Stanford University
The conference is devoted to the last results from observational and theoretical programs studying the Universe between redshifts 1 and 3, the so called redshift desert. During this more than 3.5 Gyr long period, the first massive structures condensed, and part of the massive galaxies formed through merging processes. The QSO Luminosity fonction peaked in intensity, allowing to study in detail the IGM physics. A new generation of large observational programs proposes as well to investigate the fundamental cosmology in this period. We propose to browse all these subjects, with reviews, invited talks, and shorter contributions.
Durée: 42:34 mn Date: 03 2010
Maurilio Pannella (NRAO)
