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15 results on '"R. Gobat"'

1. Evidence for Cold-stream to Hot-accretion Transition as Traced by Ly{\alpha} Emission from Groups and Clusters at 2 < z < 3.3

Author

E. Daddi, R. M. Rich, F. Valentino, S. Jin, I. Delvecchio, D. Liu, V. Strazzullo, J. Neill, R. Gobat, A. Finoguenov, F. Bournaud, D. Elbaz, B. S. Kalita, D. O’Sullivan, T. Wang, Department of Physics, Doctoral Programme in Particle Physics and Universe Sciences, Institut de Recherches sur les lois Fondamentales de l'Univers (IRFU), and Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay

Subjects
Cosmology and Nongalactic Astrophysics (astro-ph.CO), IMPACT, Astrophysics::High Energy Astrophysical Phenomena, REDSHIFT, Astrophysics::Instrumentation and Methods for Astrophysics, FOS: Physical sciences, Astronomy and Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, Galaxy accretion, 115 Astronomy, Space science, 114 Physical sciences, Astrophysics - Astrophysics of Galaxies, SHOCKS, QUASARS, Space and Planetary Science, Astrophysics of Galaxies (astro-ph.GA), Galaxy evolution, LUMINOSITY, Astrophysics::Solar and Stellar Astrophysics, GALAXY FORMATION, Astrophysics::Earth and Planetary Astrophysics, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], BLOBS, Astrophysics::Galaxy Astrophysics, Astrophysics - Cosmology and Nongalactic Astrophysics
Abstract

We present Keck Cosmic Web Imager (KCWI) observations of giant Lya halos surrounding 9 galaxy groups and clusters at 2, Comment: ApJ Letters

Published
2022
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2. The unexpectedly large dust and gas content of quiescent galaxies at $z$ > 1.4

Author

M. S. Yun, Alvio Renzini, Georgios E. Magdis, Marie Martig, Grant W. Wilson, Itziar Aretxaga, Francesco Valentino, Veronica Strazzullo, Emanuele Daddi, R. Gobat, Ho Seong Hwang, Frédéric Bournaud, Alexis Finoguenov, Matthieu Béthermin, Mark Sargent, Shuowen Jin, School of Mathematics (KIAS Séoul), Korea Institute for Advanced Study (KIAS), Astrophysique Interprétation Modélisation (AIM (UMR_7158 / UMR_E_9005 / UM_112)), Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris Diderot - Paris 7 (UPD7), National Observatory of Athens (NOA), Dark Cosmology Centre (DARK), Niels Bohr Institute [Copenhagen] (NBI), Faculty of Science [Copenhagen], University of Copenhagen = Københavns Universitet (KU)-University of Copenhagen = Københavns Universitet (KU)-Faculty of Science [Copenhagen], University of Copenhagen = Københavns Universitet (KU)-University of Copenhagen = Københavns Universitet (KU), Astronomy Centre, University of Sussex, Liverpool John Moores University (LJMU), Max-Planck-Institut für Astronomie (MPIA), Max-Planck-Gesellschaft, Laboratoire d'Astrophysique de Marseille (LAM), Aix Marseille Université (AMU)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS), INAF - Osservatorio Astronomico di Padova (OAPD), Istituto Nazionale di Astrofisica (INAF), University of Massachusetts [Amherst] (UMass Amherst), University of Massachusetts System (UMASS), Instituto Nacional de Astrofísica, Óptica y Electrónica (INAOE), Ludwig-Maximilians-Universität München (LMU), Gobat, R., Daddi, E., Magdis, G., Bournaud, F., Sargent, M., Martig, M., Jin, S., Finoguenov, A., Béthermin, M., Hwang, H. S., Renzini, A., Wilson, G. W., Aretxaga, I., Yun, M., Strazzullo, V., Valentino, F., Astrophysique Interprétation Modélisation (AIM (UMR7158 / UMR_E_9005 / UM_112)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), University of Copenhagen = Københavns Universitet (UCPH)-University of Copenhagen = Københavns Universitet (UCPH)-Faculty of Science [Copenhagen], University of Copenhagen = Københavns Universitet (UCPH)-University of Copenhagen = Københavns Universitet (UCPH), Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Aix Marseille Université (AMU)-Centre National d'Études Spatiales [Toulouse] (CNES), and Department of Physics

Subjects
COSMIC EVOLUTION, Active galactic nucleus, Stellar mass, [SDU.ASTR.CO]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Cosmology and Extra-Galactic Astrophysics [astro-ph.CO], Milky Way, MU-M, POPULATION SYNTHESIS, RADIO PROPERTIES, Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, 01 natural sciences, GMASS ULTRADEEP SPECTROSCOPY, STAR-FORMATION, ELLIPTIC GALAXIES, 0103 physical sciences, Astrophysics::Solar and Stellar Astrophysics, 010303 astronomy & astrophysics, QC, Astrophysics::Galaxy Astrophysics, QB, Physics, Spiral galaxy, 010308 nuclear & particles physics, Star formation, MASSIVE GALAXIES, Astronomy and Astrophysics, ATLAS(3D) PROJECT, 115 Astronomy, Space science, Astrophysics - Astrophysics of Galaxies, MOLECULAR GAS, Galaxy, Redshift, Interstellar medium, Astrophysics::Earth and Planetary Astrophysics, [SDU.ASTR.GA]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Galactic Astrophysics [astro-ph.GA]
Abstract

Early type galaxies (ETG) contain most of the stars present in the local Universe and, above a stellar mass of ~5e10 Msun, vastly outnumber spiral galaxies like the Milky Way. These massive spheroidal galaxies have, in the present day, very little gas or dust, and their stellar populations have been evolving passively for over 10 billion years. The physical mechanisms that led to the termination of star formation in these galaxies and depletion of their interstellar medium remain largely conjectural. In particular, there are currently no direct measurements of the amount of residual gas that might be still present in newly quiescent spheroids at high redshift. Here we show that quiescent ETGs at z~1.8, close to their epoch of quenching, contained 2-3 orders of magnitude more dust at fixed stellar mass than local ETGs. This implies the presence of substantial amounts of gas (5-10%), which was however consumed less efficiently than in more active galaxies, probably due to their spheroidal morphology, and consistently with our simulations. This lower star formation efficiency, and an extended hot gas halo possibly maintained by persistent feedback from an active galactic nucleus (AGN), combine to keep ETGs mostly passive throughout cosmic time., Comment: 16 pages, 4 main figures main, 7 supplementary figures, 2 supplementary tables; accepted for publication in Nature Astronomy

Published
2018
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3. Merger-driven star formation activity in Cl J1449+0856 at z = 1.99 as seen by ALMA and JVLA

Author

Masato Onodera, R. T. Coogan, M. Carollo, Alvio Renzini, Helmut Dannerbauer, Evangelia Tremou, Maurilio Pannella, Mark Sargent, Georgios E. Magdis, V. Strazzullo, Andrea Cimatti, R. Gobat, Matthieu Béthermin, Emanuele Daddi, Francesco Valentino, Daizhong Liu, Astrophysique Interprétation Modélisation (AIM (UMR7158 / UMR_E_9005 / UM_112)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), Ludwig-Maximilians-Universität München (LMU), Institut de Recherches sur les lois Fondamentales de l'Univers (IRFU), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay, Laboratoire d'Astrophysique de Marseille (LAM), Aix Marseille Université (AMU)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS), Institute for Astronomy [Zürich], Eidgenössische Technische Hochschule - Swiss Federal Institute of Technology [Zürich] (ETH Zürich), Max-Planck-Institut für Extraterrestrische Physik (MPE), T Coogan, R, Daddi, E, T Sargent, M, Strazzullo, V, Valentino, F, Gobat, R, Magdis, G, Bethermin, M, Pannella, M, Onodera, M, Liu, D, Cimatti, A, Dannerbauer, H, Carollo, M, Renzini, A, Tremou, E, Coogan, R. T., Daddi, E., Sargent, M. T., Strazzullo, V., Valentino, F., Gobat, R., Magdis, G., Bethermin, M., Pannella, M., Onodera, M., Liu, D., Cimatti, A., Dannerbauer, H., Carollo, M., Renzini, A., Tremou, E., Astrophysique Interprétation Modélisation (AIM (UMR_7158 / UMR_E_9005 / UM_112)), Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris Diderot - Paris 7 (UPD7), Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Aix Marseille Université (AMU)-Centre National d'Études Spatiales [Toulouse] (CNES), and Eidgenössische Technische Hochschule - Swiss Federal Institute of Technology in Zürich [Zürich] (ETH Zürich)

Subjects
Active galactic nucleus, galaxies: clusters: individual: Cl J1449+0856, galaxies: evolution, galaxies: high-redshift, galaxies: ISM, galaxies: star formation, Astrophysics - Astrophysics of Galaxies, FOS: Physical sciences, Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, Galaxy merger, 01 natural sciences, Jansky, 0103 physical sciences, Galaxies:high-redshift, 010303 astronomy & astrophysics, evolution [galaxies], Astrophysics::Galaxy Astrophysics, QB, Physics, ISM [galaxies], 010308 nuclear & particles physics, Star formation, Gas depletion, Astronomy and Astrophysics, Astronomy and Astrophysic, Galaxy, Interstellar medium, Galaxies evolution, [PHYS.ASTR.GA]Physics [physics]/Astrophysics [astro-ph]/Galactic Astrophysics [astro-ph.GA], 13. Climate action, Space and Planetary Science, Excited state, Astrophysics of Galaxies (astro-ph.GA), clusters: individual: Cl J1449+0856 [galaxies], Astrophysics::Earth and Planetary Astrophysics, star formation [galaxies], high-redshift [galaxies]
Abstract

We use ALMA and JVLA observations of the galaxy cluster Cl J1449+0856 at z=1.99, in order to study how dust-obscured star-formation, ISM content and AGN activity are linked to environment and galaxy interactions during the crucial phase of high-z cluster assembly. We present detections of multiple transitions of $^{12}$CO, as well as dust continuum emission detections from 11 galaxies in the core of Cl J1449+0856. We measure the gas excitation properties, star-formation rates, gas consumption timescales and gas-to-stellar mass ratios for the galaxies. We find evidence for a large fraction of galaxies with highly-excited molecular gas, contributing $>$50% to the total SFR in the cluster core. We compare these results with expectations for field galaxies, and conclude that environmental influences have strongly enhanced the fraction of excited galaxies in this cluster. We find a dearth of molecular gas in the galaxies' gas reservoirs, implying a high star-formation efficiency (SFE) in the cluster core, and find short gas depletion timescales $��$, 29 pages, 15 figures, 7 tables + Appendix. Accepted for publication in MNRAS

Published
2018
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4. Radio selection of the most distant galaxy clusters

Author

R. T. Coogan, Ivan Delvecchio, Veronica Strazzullo, A. Calabrò, David Elbaz, Eva Schinnerer, Mark Sargent, Vernesa Smolčić, R. Gobat, Emanuele Daddi, Tao Wang, Chiara Ferrari, Francesco Valentino, Daizhong Liu, J. Delhaize, Mladen Novak, Qiusheng Gu, Shuowen Jin, Astrophysique Interprétation Modélisation (AIM (UMR_7158 / UMR_E_9005 / UM_112)), Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris Diderot - Paris 7 (UPD7), Joseph Louis LAGRANGE (LAGRANGE), Université Nice Sophia Antipolis (... - 2019) (UNS), Université Côte d'Azur (UCA)-Université Côte d'Azur (UCA)-Observatoire de la Côte d'Azur, Université Côte d'Azur (UCA)-Centre National de la Recherche Scientifique (CNRS), Institut de Recherches sur les lois Fondamentales de l'Univers (IRFU), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay, Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), Université Côte d'Azur (UCA)-Université Nice Sophia Antipolis (... - 2019) (UNS), COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Observatoire de la Côte d'Azur, Université Côte d'Azur (UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Daddi, E, Jin, S, Strazzullo, V, Sargent, Mt, Wang, T, Ferrari, C, Schinnerer, E, Smolcic, V, Calabro, A, Coogan, R, Delhaize, J, Delvecchio, I, Elbaz, D, Gobat, R, Gu, Q, Liu, D, Novak, M, Valentino, F, Astrophysique Interprétation Modélisation (AIM (UMR7158 / UMR_E_9005 / UM_112)), Université Nice Sophia Antipolis (1965 - 2019) (UNS), COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de la Côte d'Azur, COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Université Côte d'Azur (UCA)-Université Côte d'Azur (UCA)-Centre National de la Recherche Scientifique (CNRS), Laboratoire AIM, Université Paris Diderot - Paris 7 ( UPD7 ) -Centre d'Etudes de Saclay, Joseph Louis LAGRANGE ( LAGRANGE ), Université Nice Sophia Antipolis ( UNS ), Université Côte d'Azur ( UCA ) -Université Côte d'Azur ( UCA ) -Observatoire de la Côte d'Azur, Université Côte d'Azur ( UCA ) -Centre National de la Recherche Scientifique ( CNRS ), Institut de Recherches sur les lois Fondamentales de l'Univers ( IRFU ), and Commissariat à l'énergie atomique et aux énergies alternatives ( CEA ) -Université Paris-Saclay

Subjects
Cosmology and Nongalactic Astrophysics (astro-ph.CO), Active galactic nucleus, formation [galaxies], PRIRODNE ZNANOSTI. Fizika. Astronomija i astrofizika, [ PHYS.ASTR ] Physics [physics]/Astrophysics [astro-ph], FOS: Physical sciences, Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, 01 natural sciences, galaxies: high-redshift, 0103 physical sciences, Galaxy formation and evolution, Cluster (physics), galaxies: formation, clusters: general [galaxies], NATURAL SCIENCES. Physics. Astronomy and Astrophysics, Astrophysics - Cosmology and Nongalactic Astrophysic, 010303 astronomy & astrophysics, Galaxy cluster, Astrophysics::Galaxy Astrophysics, evolution [galaxies], QB, Physics, radio continuum: galaxies, 010308 nuclear & particles physics, Star formation, galaxies: clusters: general, galaxies: evolution, galaxies: formation, galaxies: high-redshift, radio continuum: galaxies, Astronomy and Astrophysics, Astrophysics - Astrophysics of Galaxies, Galaxy, First generation, galaxies [radio continuum], Square degree, galaxies: clusters: general, galaxies: evolution, Astrophysics - Cosmology and Nongalactic Astrophysics, Space and Planetary Science, Astrophysics of Galaxies (astro-ph.GA), galaxie [radio continuum], [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], high-redshift [galaxies]
Abstract

We show that the most distant X-ray detected cluster known to date, ClJ1001 at z=2.506, hosts a strong overdensity of radio sources. Six of them are individually detected (within 10") in deep 0.75" resolution VLA 3GHz imaging, with S(3GHz)>8uJy. Of the six, AGN likely affects the radio emission in two galaxies while star formation is the dominant source powering the remaining four. We searched for cluster candidates over the full COSMOS 2-square degree field using radio-detected 3GHz sources and looking for peaks in Sigma5 density maps. ClJ1001 is the strongest overdensity by far with >10sigma, with a simple z_phot>1.5 preselection. A cruder photometric rejection of z2.5. Samples of hundreds such high-redshift clusters could potentially constrain cosmological parameters and test cluster and galaxy formation models., ApJ Letters in press

Published
2017
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5. Predicting emission line fluxes and number counts of distant galaxies for cosmological surveys

Author

Emanuele Daddi, G. Zamorani, Alvio Renzini, A. Puglisi, Andrea Cimatti, Maurilio Pannella, G. Rodighiero, Daichi Kashino, Francesco Valentino, Lucia Pozzetti, John D. Silverman, R. Gobat, Astrophysique Interprétation Modélisation (AIM (UMR7158 / UMR_E_9005 / UM_112)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), Laboratoire AIM, Université Paris Diderot - Paris 7 ( UPD7 ) -Centre d'Etudes de Saclay, Astrophysique Interprétation Modélisation (AIM (UMR_7158 / UMR_E_9005 / UM_112)), Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris Diderot - Paris 7 (UPD7), Valentino, F., Daddi, E., Silverman, J. D., Puglisi, A., Kashino, D., Renzini, A., Cimatti, A., Pozzetti, L., Rodighiero, G., Pannella, M., Gobat, R., Zamorani, G., and ITA

Subjects
Cosmology and Nongalactic Astrophysics (astro-ph.CO), Astrophysics::High Energy Astrophysical Phenomena, [ PHYS.ASTR ] Physics [physics]/Astrophysics [astro-ph], FOS: Physical sciences, Astrophysics::Cosmology and Extragalactic Astrophysics, Astrophysics, 01 natural sciences, Photometry (optics), Flux (metallurgy), galaxies: high-redshift, 0103 physical sciences, Range (statistics), Emission spectrum, Spectroscopy, 010303 astronomy & astrophysics, distances and redshifts, galaxies: star, formation, galaxies: statistics, large-scale structure of Universe, cosmology: observations [galaxies], Astrophysics::Galaxy Astrophysics, Line (formation), Physics, galaxies: distances and redshifts, galaxies: high-redshift, galaxies: star formation, galaxies: statistics, large-scale structure of Universe, cosmology: observations, 010308 nuclear & particles physics, Astronomy, Astronomy and Astrophysics, Astrophysics - Astrophysics of Galaxies, Galaxy, Redshift, 13. Climate action, Space and Planetary Science, Astrophysics of Galaxies (astro-ph.GA), galaxies: star formation, cosmology: observations, galaxies: distances and redshifts, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], Astrophysics - Cosmology and Nongalactic Astrophysics
Abstract

We estimate the number counts of line emitters at high redshift and their evolution with cosmic time based on a combination of photometry and spectroscopy. We predict the H α, H β, [O II], and [O III] line fluxes for more than 35 000 galaxies down to stellar masses of ∼109 M in the COSMOS and GOODS-S fields, applying standard conversions and exploit ing the spectroscopic coverage of the FMOS-COSMOS survey at z ∼ 1.55 to calibrate the predictions. We calculate the number counts of H α, [O II], and [O III] emitters down to fluxes of 1 × 10−17 erg cm−2 s−1 in the range 1.4 < z < 1.8 covered by the FMOS-COSMOS survey. We model the time evolution of the differential and cumulative H α counts, steeply declining at the brightest fluxes. We expect ∼9300–9700 and ∼2300–2900 galaxies deg−2 for fluxes ≥1 × 10−16 and ≥2 × 10−16 erg cm−2 s−1 over the range of 0.9 < z < 1.8. We show that the observed evolution of the main sequence of galaxies with redshift is enough to reproduce the observed counts variation at 0.2 < z < 2.5. We characterize the physical properties of the H α emitters with fluxes ≥2 × 10−16 erg cm−2 s−1 including their stellar masses, UV sizes, [N II]/H α ratios and H α equivalent widths. An aperture of R ∼ Re ∼ 0.5 arcsec maximizes the signal-to-noise ratio for a detection, whilst causing a factor of ∼2 × flux losses, influencing the recoverable number counts, if neglected. Our approach, based on deep and large photometric data sets, reduces the uncertainties on the number counts due to the selection and spectroscopic samplings whilst exploring low fluxes. We publicly release the line flux predictions for the explored photometric samples., Monthly Notices of the Royal Astronomical Society, 472 (4), ISSN:0035-8711, ISSN:1365-2966, ISSN:1365-8711

Published
2017
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6. Star formation histories of early-type galaxies at z = 1.2 in cluster and field environments

Author

Alessandro Rettura, Piero Rosati, V. Strazzullo, R. Gobat, Mario Nonino, Ricardo Demarco, Gobat, R, Rosati, P, Strazzullo, V, Rettura, A, Demarco, R, and Nonino, M

Subjects
Physics, Stellar population, Field (physics), Star formation, Astrophysics (astro-ph), FOS: Physical sciences, High density, Astronomy and Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, Astrophysics, Galaxy, Early type, Stars, Space and Planetary Science, Cluster (physics), Astrophysics::Solar and Stellar Astrophysics, Astrophysics::Galaxy Astrophysics
Abstract

We derive the star formation histories of early-type galaxies at z = 1.2 in both low and high density environments. To this purpose, we compare the co-added spectroscopic and 8-9 band photometric data of 43 mass selected early-type galaxies in the massive cluster RDCS J1252.9-2927 and the GOODS/CDF-S field with a large grid of composite stellar population models. We find that the cluster early-type galaxies formed the bulk of their stars approximately 0.5 Gyr earlier than early-types in the field, whereas field early-types presumably finish forming their stellar content on a longer time scale. Such a difference is particularly evident at lower masses but becomes negligible for the most massive galaxies. While our differential analysis of the stellar population parameters of cluster and field galaxies in the same mass range convincingly shows distinct star formation histories, the absolute age difference remains model dependent. Using the star formation histories that best fit the SEDs of the red sequence galaxies in RDCS 1252.9-2927, we reconstruct the evolution of the cluster red sequence and find that it was established over 1 Gyr and is expected to dissolve by z ~ 2., Comment: 10 pages, 11 figures, accepted for publication in A&A, references added, minor corrections

Published
2008
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7. CLASH: Extending galaxy strong lensing to small physical scales with distant sources highly-magnified by galaxy cluster members

Author

John Moustakas, Italo Balestra, Leonidas A. Moustakas, Holland C. Ford, Anton M. Koekemoer, Tom Broadhurst, Narciso Benítez, Andrea Biviano, Matthias Bartelmann, Stephanie Jouvel, Leopoldo Infante, Julian Merten, Rychard Bouwens, Claudio Grillo, Genevieve J. Graves, Larry Bradley, Peter Melchior, Keiichi Umetsu, Daniel D. Kelson, Megan Donahue, Lise Christensen, Elinor Medezinski, Alberto Molino, Dan Coe, Eros Vanzella, Amata Mercurio, A. Monna, W. Zheng, Adi Zitrin, Stella Seitz, Massimo Meneghetti, Marc Postman, Piero Rosati, Ofer Lahav, Doron Lemze, V. Presotto, Mario Nonino, and R. Gobat

Subjects
Physics, Cosmology and Nongalactic Astrophysics (astro-ph.CO), Mass distribution, Stellar population, Velocity dispersion, FOS: Physical sciences, Astronomy and Astrophysics, Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, Astrophysics - Astrophysics of Galaxies, Redshift, Galaxy, law.invention, Lens (optics), Space and Planetary Science, law, Astrophysics of Galaxies (astro-ph.GA), Galaxy cluster, Astrophysics::Galaxy Astrophysics, Photometric redshift, Astrophysics - Cosmology and Nongalactic Astrophysics
Abstract

We present a strong lensing system in which a double source is imaged 5 times by 2 early-type galaxies. We take advantage in this target of the multi-band photometry obtained as part of the CLASH program, complemented by the spectroscopic data of the VLT/VIMOS and FORS2 follow-up campaign. We use a photometric redshift of 3.7 for the source and confirm spectroscopically the membership of the 2 lenses to the galaxy cluster MACS J1206.2-0847 at redshift 0.44. We exploit the excellent angular resolution of the HST/ACS images to model the 2 lenses in terms of singular isothermal sphere profiles and derive robust effective velocity dispersions of (97 +/- 3) and (240 +/- 6) km/s. The total mass distribution of the cluster is also well characterized by using only the local information contained in this lensing system, that is located at a projected distance of more than 300 kpc from the cluster luminosity center. According to our best-fitting lensing and composite stellar population models, the source is magnified by a total factor of 50 and has a luminous mass of about (1.0 +/- 0.5) x 10^{9} M_{Sun}. By combining the total and luminous mass estimates of the 2 lenses, we measure luminous over total mass fractions projected within the effective radii of 0.51 +/- 0.21 and 0.80 +/- 0.32. With these lenses we can extend the analysis of the mass properties of lens early-type galaxies by factors that are about 2 and 3 times smaller than previously done with regard to, respectively, velocity dispersion and luminous mass. The comparison of the total and luminous quantities of our lenses with those of astrophysical objects with different physical scales reveals the potential of studies of this kind for investigating the internal structure of galaxies. These studies, made possible thanks to the CLASH survey, will allow us to go beyond the current limits posed by the available lens samples in the field., Comment: 20 pages, 10 figures, accepted for publication in the Astrophysical Journal

Published
2014

8. Photometric mass and mass decomposition in early-type lens galaxies

Author

Marco Lombardi, R. Gobat, Claudio Grillo, and Piero Rosati

Subjects
Physics, education.field_of_study, Cosmology and Nongalactic Astrophysics (astro-ph.CO), Einstein ring, Stellar mass, Stellar population, Metallicity, Population, Dark matter, FOS: Physical sciences, Astronomy and Astrophysics, Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, Astrophysics - Astrophysics of Galaxies, Galaxy, Redshift, symbols.namesake, Space and Planetary Science, Astrophysics of Galaxies (astro-ph.GA), symbols, education, Astrophysics::Galaxy Astrophysics, Astrophysics - Cosmology and Nongalactic Astrophysics
Abstract

By using the SDSS multicolor photometry and lens modeling, we study stellar mass properties and the luminous and dark matter composition of the 57 early-type lens galaxies analyzed by the SLACS Survey. We fit the lens SEDs composed of ugriz magnitudes with a three-parameter grid of different composite stellar population models, computed by adopting solar metallicity and various IMFs, and we employ the best-fit values of the total projected mass enclosed within the Einstein ring of each system. We measure size-stellar mass and surface stellar mass density-stellar mass relations consistent with those determined for non-lens galaxies. We find statistically significant evidence that more massive lens galaxies tend to form in regions of higher galaxy density, as for all early-type galaxies. We measure for the corresponding stellar quantities the same scaling law between effective mass-to-light ratio and mass, that is used to explain the "tilt" of the FP, and the same evolution of the effective mass-to-light ratio with redshift, that can be derived from the FP. We conclude that the lens total mass is linearly proportional to the luminous mass, at a more than 99% CL. In addition, by assuming that the lens galaxies are homologous systems, we study their distribution of dark matter and estimate a value on the order of 30% for the dark over total projected mass fraction contained within the average Einstein radius of approximately 4 kpc. These results suggest that early-type lens galaxies are an unbiased subsample representative of the whole sample of early-type galaxies. This allows us to generalize our findings on dark matter in lens galaxies to the population of massive early-type galaxies. We note that, for the assumed metallicity, a Salpeter IMF describes well the lens sample., Comment: 16 pages, 14 figures, accepted by Astronomy & Astrophysics

Published
2009
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9. Cluster galaxies at redshift 1.4

Author

V. Strazzullo, P. Rosati, C. Lidman, C. Mullis, R. Demarco, R. Gobat, M. Nonino, Giuliana Giobbi, Amedeo Tornambe, Gabriella Raimondo, Marco Limongi, L. A. Antonelli, Nicola Menci, and Enzo Brocato

Subjects
Luminous infrared galaxy, Physics, Astrophysics::High Energy Astrophysical Phenomena, Surface brightness fluctuation, Astronomy, Quasar, Astrophysics::Cosmology and Extragalactic Astrophysics, Astrophysics, Redshift survey, Elliptical galaxy, Astrophysics::Solar and Stellar Astrophysics, Brightest cluster galaxy, Lenticular galaxy, Astrophysics::Galaxy Astrophysics, Luminosity function (astronomy)
Abstract

We present new and partly preliminary results on the galaxy populations in the massive, X‐ray luminous cluster XMMU J2235‐2557 at redshift 1.39. We use high‐quality optical and NIR data to study the luminosity function of cluster galaxies at different wavelengths (restframe ≈3500, 6500, 9000 A), confirming previous results at lower redshifts showing that the redshift evolution of the characteristic luminosity M* of the luminosity function is consistent with passive evolution of a stellar population formed at redshift z>2. We build a restframe U‐R vs R color‐magnitude diagram from high‐resolution z‐ and H‐band images of XMMU J2235‐2557 within R≈700 kpc, finding a tight red sequence already in place. When compared to models of elliptical galaxy formation [1], the slope and location of the red sequence indicate a formation redshift of z≈3 for the bulk of the stars in red sequence galaxies, at least brighter than M*+1. Spectral energy distribution fitting of multicolor data sampling the restframe ≈2700–9000 A...

Published
2009
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10. The red sequence of high-redshift clusters: A comparison with cosmological galaxy formation models

Author

Veronica Strazzullo, P. Rosati, Ricardo Demarco, R. Gobat, Nicola Menci, Simona Mei, Alessandro Rettura, Menci, N, Rosati, P, Gobat, R, Strazzullo, V, Rettura, A, Mei, S, and Demarco, R

Subjects
Physics, COSMIC cancer database, Field (physics), Stellar mass, Astrophysics (astro-ph), FOS: Physical sciences, Astronomy and Astrophysics, Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, Galaxy, Redshift, Space and Planetary Science, Cluster (physics), Galaxy formation and evolution, Galaxy cluster, Astrophysics::Galaxy Astrophysics
Abstract

We compare the results from a semi-analytic model of galaxy formation with spectro-photometric observations of distant galaxy clusters observed in the range 0.8< z< 1.3. We investigate the properties of their red sequence (RS) galaxies and compare them with those of the field at the same redshift. In our model we find that i) a well-defined, narrow RS is obtained already by z= 1.2; this is found to be more populated than the field RS, analogously to what observed and predicted at z=0; ii) the predicted U-V rest-frame colors and scatter of the cluster RS at z=1.2 have average values of 1 and 0.15 respectively, with a cluster-to-cluster variance of 0.2 and 0.06, respectively. The scatter of the RS of cluster galaxies is around 5 times smaller than the corresponding field value; iii) when the RS galaxies are considered, the mass growth histories of field and cluster galaxies at z=1.2 are similar, with 90 % of the stellar mass of RS galaxies at z=1.2 already formed at cosmic times t=2.5 Gyr, and 50 % at t=1 Gyr; v) the predicted distribution of stellar ages of RS galaxies at z=1.2 peaks at 3.7 Gyr for both cluster and field populations; however, for the latter the distribution is significantly skewed toward lower ages. When compared with observations, the above findings show an overall consistency, although the average value 0.07 of the observed cluster RS scatter (U-V colors) at z=1.2 is smaller than the corresponding model central value. We discuss the physical origin and the significance of the above results in the framework of cosmological galaxy formation., 14 pages, accepted for publication in ApJ. Updated one reference

Published
2008

11. A twelve-image gravitational lens system in the z ~= to 0.84 cluster Cl J0152.7-1357

Author

Claudio Grillo, Ricardo Demarco, Giuseppe Bertin, Christopher Lidman, Marco Lombardi, Mario Nonino, Piero Rosati, R. Gobat, and Veronica Motta

Subjects
Physics, Einstein ring, Astrophysics (astro-ph), FOS: Physical sciences, Sigma, Astronomy and Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, Astrophysics, Measure (mathematics), Galaxy, Redshift, Einstein radius, symbols.namesake, Gravitational lens, Space and Planetary Science, symbols, Astrophysics::Galaxy Astrophysics, Parametric statistics
Abstract

Gravitational lens modeling is presented for the first discovered example of a three-component source for which each component is quadruply imaged. The lens is a massive galaxy member of the cluster Cl J0152.7-1357 at z ~ 0.84. Taking advantage of this exceptional configuration and of the excellent angular resolution of the HST/ACS, we measure the properties of the lens. Several parametric macroscopic models were developed for the lens galaxy, starting from pointlike to extended image models. For a lens model in terms of a singular isothermal sphere with external shear, the Einstein radius is found to be R_{E} = (9.54 +/- 0.15) kpc. The external shear points to the cluster's northern mass peak. The unknown redshift of the source is determined to be higher than 1.9 and lower than 2.9. Our estimate of the lensing projected total mass inside the Einstein radius, M_{len}(R < 9.54 kpc), depends on the source distance and lies between 4.6 and 6.2 x 10^{11} M_{Sun}. This result turns out to be compatible with the dynamical estimate based on an isothermal model. By considering the constraint on the stellar mass-to-light ratio that comes from the evolution of the Fundamental Plane, we can exclude the possibility that at more than 4 sigma level the total mass enclosed inside the Einstein ring is only luminous matter. Moreover, the photometric-stellar mass measurement within the Einstein radius gives a minimum value of 50% (1 sigma) for the dark-to-total matter fraction. The lensing analysis has allowed us to investigate the distribution of mass of the deflector, also providing some interesting indications on scales that are larger and smaller than the Einstein radius of the lens galaxy. The combination of different diagnostics has proved to be essential in determining quantities that otherwise would have not been directly measurable with the current data., 10 pages, 9 figures, accepted by Astronomy & Astrophysics

Published
2008

12. VLT and ACS observations of RDCS J1252.9-2927: dynamical structure and galaxy populations in a massive cluster at z=1.237

Author

Paolo Tozzi, Nicole Homeier, G. Hartig, Garth D. Illingworth, Brad Holden, Leopoldo Infante, R. Gobat, Ricardo Demarco, Marc Postman, V. Mainieri, Roderik Overzier, Veronica Motta, Alessandro Rettura, Mario Nonino, Narciso Benítez, V. Strazzullo, Piero Rosati, A. van der Wel, Myungkook J. Jee, W. Zheng, Christopher Lidman, Andrew Zirm, Holland C. Ford, John P. Blakeslee, Marisa Girardi, Simona Mei, Mark Clampin, Felipe Menanteau, Spencer A. Stanford, Demarco, R., Rosati, P., Lidman, C., Girardi, Marisa, Nonino, M., Rettura, A., Strazzullo, Veronica, van der Wel, A., Ford, H. C., Mainieri, V., Holden, B. P., Stanford, S. A., Blakeslee, J. P., Gobat, R., Postman, M., Tozzi, P., Overzier, R. A., Zirm, A. W., Benítez, N., Homeier, N. L., Illingworth, G. D., Infante, L., Jee, M. J., Mei, S., Menanteau, F., Motta, V., Zheng, W., Clampin, M., and Hartig, G.

Subjects
J1252.9-2927), Structure formation, clusters : general [galaxies], H-ALPHA, Dark matter, FOS: Physical sciences, DEEP-FIELD-NORTH, Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, 01 natural sciences, Advanced Camera for Surveys, 0103 physical sciences, Cluster (physics), COLOR-MAGNITUDE RELATION, STAR-FORMING GALAXIES, TO-LIGHT RATIOS, galaxy clusters, Astrophysics::Solar and Stellar Astrophysics, 010306 general physics, 010303 astronomy & astrophysics, Galaxy cluster, Astrophysics::Galaxy Astrophysics, Physics, clusters : individual (ClG [galaxies], SCALE-INDEPENDENT METHOD, Astrophysics (astro-ph), Astronomy and Astrophysics, HUBBLE-SPACE-TELESCOPE, HIGH-REDSHIFT CLUSTERS, Redshift, Galaxy, Stars, COMPACT BLUE GALAXIES, Physics and Astronomy, Space and Planetary Science, MORPHOLOGY-DENSITY RELATION
Abstract

We present results from an extensive spectroscopic survey, carried out with VLT FORS, and from an extensive multiwavelength imaging data set from the HST Advanced Camera for Surveys and ground based facilities, of the cluster of galaxies RDCS J1252.9-2927. We have spectroscopically confirmed 38 cluster members in the redshift range 1.22 < z < 1.25. A cluster median redshift of z=1.237 and a rest-frame velocity dispersion of 747^{+74}_{-84} km/s are obtained. Using the 38 confirmed redshifts, we were able to resolve, for the first time at z > 1, kinematic structure. The velocity distribution, which is not Gaussian at the 95% confidence level, is consistent with two groups that are also responsible for the projected east-west elongation of the cluster. The groups are composed of 26 and 12 galaxies with velocity dispersions of 486^{+47}_{-85} km/s and 426^{+57}_{-105} km/s, respectively. The elongation is also seen in the intracluster gas and the dark matter distribution. This leads us to conclude that RDCS J1252.9-2927 has not yet reached a final virial state. We extend the analysis of the color-magnitude diagram of spectroscopic members to more than 1 Mpc from the cluster center. The scatter and slope of non-[OII]-emitting cluster members in the near-IR red sequence is similar to that seen in clusters at lower redshift. Furthermore, most of the galaxies with luminosities greater than ~ K_s*+1.5 do not show any [OII], indicating that these more luminous, redder galaxies have stopped forming stars earlier than the fainter, bluer galaxies. Our observations provide detailed dynamical and spectrophotometric information on galaxies in this exceptional high-redshift cluster, delivering an in-depth view of structure formation at this epoch only 5 Gyr after the Big Bang., 29 pages. 16 figures. ApJ accepted. Tables 2,3 and 5, figure 1 and the full figure 5 will be available in the paper and electronic editions from ApJ. v2: minor corrections to the abstract and text to match the Journal's version

Published
2007

13. Stellar mass estimates in early-type galaxies from lensing+dynamical and photometric measurements

Author

Piero Rosati, Marco Lombardi, Claudio Grillo, and R. Gobat

Subjects
Physics, Stellar mass, Stellar population, Astrophysics (astro-ph), FOS: Physical sciences, Astronomy and Astrophysics, Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, Galaxy, Einstein radius, Space and Planetary Science, Stellar dynamics, Elliptical galaxy, Spectral energy distribution, Astrophysics::Solar and Stellar Astrophysics, Astrophysics::Earth and Planetary Astrophysics, Fundamental plane (elliptical galaxies), Astrophysics::Galaxy Astrophysics
Abstract

In this paper we compare two different diagnostics for estimating stellar masses in early-type galaxies and we establish their level of reliability. In particular, we consider the well-studied sample of 15 field elliptical galaxies selected from the Sloan Lens ACS (SLACS) Survey (z = 0.06-0.33). We examine here the correlation between the stellar mass values, enclosed inside the Einstein radius of each lens, based on analyses of lensing and stellar dynamics combined and based on multiwavelength photometry spectral template fitting. The lensing+dynamics stellar mass is obtained from the published SLACS Survey results, assuming a two-component density distribution model and a prior from the fundamental plane on the mass-to-light ratio for the lens galaxies. The photometric stellar mass is measured by fitting the observed spectral energy distribution of the galaxies (from the SDSS multi-band photometry over 354-913 nm) with composite stellar population templates, under the assumption that light traces stellar mass. The two methods are completely independent. They rely on several different assumptions, and so, in principle, both can have significant biases. Based on our sample of massive galaxies, we find consistency between the lensing+dynamics and the photometric mass estimates. We obtain a Pearson linear correlation coefficient of 0.94 and a median value of the ratio between the former and the latter mass measurements of 1.1+/-0.1. This suggests that both methods can separately yield reliable stellar masses of early-type galaxies, and confirms that photometric mass estimates are accurate, as long as optical/near-IR rest frame photometry is available., Comment: 4 pages, 2 figures, accepted by Astronomy & Astrophysics

Published
2007
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14. Improved constraints on the expansion rate of the Universe up to z similar to 1.1 from the spectroscopic evolution of cosmic chronometers

Author

Piero Rosati, J. F. Le Borgne, C. Knobel, Laurence Tresse, James Dunlop, S. Foucaud, K. Kovac, Angela Bongiorno, Michele Moresco, G. Zamorani, Lidia Tasca, Daniela Vergani, Preethi Nair, Marc Kamionkowski, C. Diener, Olga Cucciati, Graziano Coppa, Lucia Pozzetti, S. Bardelli, Michele Cirasuolo, Anton M. Koekemoer, Ross J. McLure, C. López-Sanjuan, Niraj Welikala, Vincenzo Mainieri, C. M. Carollo, Rongmon Bordoloi, Andrea Cimatti, Raul Jimenez, Licia Verde, John D. Silverman, F. Lamareille, Karina Caputi, H. J. Pearce, Masayuki Tanaka, Luke A. Barnes, A. Iovino, Jean-Paul Kneib, S. de la Torre, William G. Hartley, V. Presotto, Christian Maier, L. de Ravel, E. J. Bradshaw, S. Lilly, Yingjie Peng, Robert Chuter, P. Kampczyk, M. Mignoli, H. J. McCracken, Bianca Garilli, Adam Stanford, Marco Scodeggio, Italo Balestra, P. Franzetti, Omar Almaini, Thierry Contini, R. Pello, Enrique Pérez-Montero, V. Le Brun, Raphael Gobat, A. Cappi, Micol Bolzonella, Alvio Renzini, Daniel Stern, Pascal Oesch, O. Le Fèvre, E. Zucca, Dipartimento di Astronomia, Alma Mater Studiorum Università di Bologna [Bologna] (UNIBO), Department of Chemical Engineering, Columbia University, Columbia University [New York], INAF - Osservatorio Astronomico di Bologna (OABO), Istituto Nazionale di Astrofisica (INAF), Istituto di Astrofisica Spaziale e Fisica cosmica - Bologna (IASF-Bo), SUPA, Institute for Astronomy, University of Edinburgh, Institut de recherche en astrophysique et planétologie (IRAP), Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire Midi-Pyrénées (OMP), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Centre National de la Recherche Scientifique (CNRS), European Southern Observatory (ESO), Jet Propulsion Laboratory (JPL), NASA-California Institute of Technology (CALTECH), Departament d'Astronomia i Meteorologia [Barcelona], Universitat de Barcelona (UB), INAF - Osservatorio Astronomico di Brera (OAB), University of Chicago, Laboratoire Astrophysique de Toulouse-Tarbes (LATT), Ecole Polytechnique Fédérale de Lausanne (EPFL), Laboratoire d'Astrophysique de Marseille (LAM), Aix Marseille Université (AMU)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS), Institute for Astronomy [Zürich], Eidgenössische Technische Hochschule - Swiss Federal Institute of Technology [Zürich] (ETH Zürich), INAF - Osservatorio Astronomico di Padova (OAPD), INAF- Milano, INAF - Osservatorio Astronomico di Trieste (OAT), Astrophysique Interprétation Modélisation (AIM (UMR7158 / UMR_E_9005 / UM_112)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), College of Computing (GATECH), Georgia Institute of Technology [Atlanta], AUTRES, Dipartimento di Fisica, Università degli Studi di Milano-Bicocca = University of Milano-Bicocca (UNIMIB)-Università degli Studi di Milano = University of Milan (UNIMI), Laboratoire Léon Brillouin (LLB - UMR 12), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), Hunan Normal University (HNU), Università degli studi di Trieste = University of Trieste, INAF - Osservatorio Astrofisico di Arcetri (OAA), Joseph Louis LAGRANGE (LAGRANGE), Université Nice Sophia Antipolis (1965 - 2019) (UNS), COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de la Côte d'Azur, COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Université Côte d'Azur (UCA)-Université Côte d'Azur (UCA)-Centre National de la Recherche Scientifique (CNRS), Space Telescope Science Institute (STSci), Institut d'Astrophysique de Paris (IAP), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Universitat de Barcelona, Institut national des sciences de l'Univers (INSU - CNRS)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Observatoire Midi-Pyrénées (OMP), Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Centre National de la Recherche Scientifique (CNRS), California Institute of Technology (CALTECH)-NASA, Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire Midi-Pyrénées (OMP), Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Aix Marseille Université (AMU)-Centre National d'Études Spatiales [Toulouse] (CNES), Astrophysique Interprétation Modélisation (AIM (UMR_7158 / UMR_E_9005 / UM_112)), Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris Diderot - Paris 7 (UPD7), Università degli Studi di Milano-Bicocca [Milano] (UNIMIB)-Università degli Studi di Milano [Milano] (UNIMI), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS)-Université Paris-Saclay, Hunan Normal University, Università degli studi di Trieste, Université Côte d'Azur (UCA)-Université Nice Sophia Antipolis (... - 2019) (UNS), COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Observatoire de la Côte d'Azur, Université Côte d'Azur (UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC), Università di Bologna [Bologna] (UNIBO), Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS), Institut de Ciènces del Cosmos (ICC), Universitat de Barcelona (UB)-Universitat de Barcelona (UB), Istituto Nazionale di Astrofisica - Osservatorio Astronomico di Brera (INAF), Centre National de la Recherche Scientifique (CNRS)-Observatoire Midi-Pyrénées (OMP), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Institut national des sciences de l'Univers (INSU - CNRS)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées, Eidgenössische Technische Hochschule - Swiss Federal Institute of Technology in Zürich [Zürich] (ETH Zürich), Università degli studi di Milano [Milano]-Università di Milano-Bicocca, Université Nice Sophia Antipolis (... - 2019) (UNS), Université Côte d'Azur (UCA)-Université Côte d'Azur (UCA)-Observatoire de la Côte d'Azur, Université Côte d'Azur (UCA)-Centre National de la Recherche Scientifique (CNRS), M. Moresco, A. Cimatti, R. Jimenez, L. Pozzetti, G. Zamorani, M. Bolzonella, J. Dunlop, F. Lamareille, M. Mignoli, H. Pearce, P. Rosati, D. Stern, L. Verde, E. Zucca, C.M. Carollo, T. Contini, J.-P. Kneib, O. Le Fevre, S.J. Lilly, V. Mainieri, A. Renzini, M. Scodeggio, I. Balestra, R. Gobat, R. McLure, S. Bardelli, A. Bongiorno, K. Caputi, O. Cucciati, S. de la Torre, L. de Ravel, P. Franzetti, B. Garilli, A. Iovino, P. Kampczyk, C. Knobel, K. Kovac, J.-F. Le Borgne, V. Le Brun, C. Maier, R. Pello', Y. Peng, E. Perez-Montero, V. Presotto, J.D. Silverman, M. Tanaka, L.A.M. Tasca, L. Tresse, D. Vergani, O. Almaini, L. Barne, R. Bordoloi, E. Bradshaw, A. Cappi, R. Chuter, M. Cirasuolo, G. Coppa, C. Diener, S. Foucaud, W. Hartley, M. Kamionkowski, A.M. Koekemoer, C. Lopez-Sanjuan, H.J. McCracken, P. Nair, P. Oesch, A. Stanford, and N. Welikala

Subjects
Astrofísica, Cosmology and Nongalactic Astrophysics (astro-ph.CO), galaxy survey, dark energy experiments, Stellar population, FOS: Physical sciences, Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, Expanding universe, 01 natural sciences, symbols.namesake, Expansió de l'univers, 0103 physical sciences, 010303 astronomy & astrophysics, Astrophysics::Galaxy Astrophysics, Physics, [SDU.ASTR]Sciences of the Universe [physics]/Astrophysics [astro-ph], 010308 nuclear & particles physics, Star formation, Astronomy and Astrophysics, Galaxies, Billion years, Galaxy, Redshift, Galàxies, symbols, Elliptical galaxy, Hubble's law, Quintessence, Astrophysics - Cosmology and Nongalactic Astrophysics
Abstract

We present new improved constraints on the Hubble parameter H(z) in the redshift range 0.15 < z < 1.1, obtained from the differential spectroscopic evolution of early-type galaxies as a function of redshift. We extract a large sample of early-type galaxies (\sim11000) from several spectroscopic surveys, spanning almost 8 billion years of cosmic lookback time (0.15 < z < 1.42). We select the most massive, red elliptical galaxies, passively evolving and without signature of ongoing star formation. Those galaxies can be used as standard cosmic chronometers, as firstly proposed by Jimenez & Loeb (2002), whose differential age evolution as a function of cosmic time directly probes H(z). We analyze the 4000 �� break (D4000) as a function of redshift, use stellar population synthesis models to theoretically calibrate the dependence of the differential age evolution on the differential D4000, and estimate the Hubble parameter taking into account both statistical and systematical errors. We provide 8 new measurements of H(z) (see Tab. 4), and determine its change in H(z) to a precision of 5-12% mapping homogeneously the redshift range up to z \sim 1.1; for the first time, we place a constraint on H(z) at z \neq 0 with a precision comparable with the one achieved for the Hubble constant (about 5-6% at z \sim 0.2), and covered a redshift range (0.5 < z < 0.8) which is crucial to distinguish many different quintessence cosmologies. These measurements have been tested to best match a ��CDM model, clearly providing a statistically robust indication that the Universe is undergoing an accelerated expansion. This method shows the potentiality to open a new avenue in constrain a variety of alternative cosmologies, especially when future surveys (e.g. Euclid) will open the possibility to extend it up to z \sim 2., 34 pages, 15 figures, 6 tables, published in JCAP. It is a companion to Moresco et al. (2012b, http://arxiv.org/abs/1201.6658) and Jimenez et al. (2012, http://arxiv.org/abs/1201.3608). The H(z) data can be downloaded at http://www.physics-astronomy.unibo.it/en/research/areas/astrophysics/cosmology-with-cosmic-chronometers

Published
2012
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15. A z = 1.82 Analog of Local Ultra-massive Elliptical Galaxies

Author

S. J. Lilly, Michele Cappellari, Yoshihiko Yamada, Olivier Ilbert, David B. Sanders, Kentaro Motohara, Raphael Gobat, Mauro Giavalisco, Alvio Renzini, Alessandro Cimatti, Kouji Ohta, H. J. McCracken, Y. Taniguchi, Xu Kong, Peter Capak, M. Carollo, Naoyuki Tamura, C. Mancini, Masato Onodera, N. Z. Scoville, Nobuo Arimoto, Emanuele Daddi, Astrophysique Interprétation Modélisation (AIM (UMR_7158 / UMR_E_9005 / UM_112)), Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris Diderot - Paris 7 (UPD7), Sub-department of Astrophysics [Oxford], Department of Physics [Oxford], University of Oxford [Oxford]-University of Oxford [Oxford], National Astronomical Observatory of Japan (NAOJ), INAF - Osservatorio Astronomico di Padova (OAPD), Istituto Nazionale di Astrofisica (INAF), Institut d'Astrophysique de Paris (IAP), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Spitzer Science Center, California Institute of Technology (CALTECH), Institute for Astronomy [Zürich], Eidgenössische Technische Hochschule - Swiss Federal Institute of Technology in Zürich [Zürich] (ETH Zürich), Dipartimento di Astronomia, Università di Bologna [Bologna] (UNIBO), Department of Astronomy [Amherst], University of Massachusetts [Amherst] (UMass Amherst), University of Massachusetts System (UMASS)-University of Massachusetts System (UMASS), Laboratoire d'Astrophysique de Marseille (LAM), Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Aix Marseille Université (AMU)-Centre National d'Études Spatiales [Toulouse] (CNES), Center for Astrophysics [Hefei], University of Science and Technology of China [Hefei] (USTC), Institute of Astronomy, The University of Tokyo, Department of Astronomy, Kyoto University [Kyoto], Institute for Astronomy [Honolulu], University of Hawai‘i [Mānoa] (UHM), Research Center for Space and Cosmic Evolution (RCSCE), Ehime University [Matsuyama], UPGAL, Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC), Eidgenössische Technische Hochschule - Swiss Federal Institute of Technology [Zürich] (ETH Zürich), Alma Mater Studiorum Università di Bologna [Bologna] (UNIBO), The University of Tokyo (UTokyo), Astrophysique Interprétation Modélisation (AIM (UMR7158 / UMR_E_9005 / UM_112)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), University of Oxford-University of Oxford, Aix Marseille Université (AMU)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS), Kyoto University, Ehime University [Matsuyama, Japon], M. Onodera, E. Daddi, R. Gobat, M. Cappellari, N. Arimoto, A. Renzini, Y. Yamada, H. J. McCracken, C. Mancini, P. Capak, M. Carollo, A. Cimatti, M. Giavalisco, O. Ilbert, X. Kong, S. Lilly, K. Motohara, K. Ohta, D. B. Sander, N. Scoville, N. Tamura, and Y. Taniguchi

Subjects
Cosmology and Nongalactic Astrophysics (astro-ph.CO), Stellar population, Stellar mass, media_common.quotation_subject, FOS: Physical sciences, Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, 01 natural sciences, 0103 physical sciences, Astrophysics::Solar and Stellar Astrophysics, 010303 astronomy & astrophysics, Astrophysics::Galaxy Astrophysics, media_common, Physics, 010308 nuclear & particles physics, Velocity dispersion, Astronomy and Astrophysics, Virial mass, Galaxy, Redshift, Universe, [PHYS.ASTR.GA]Physics [physics]/Astrophysics [astro-ph]/Galactic Astrophysics [astro-ph.GA], Space and Planetary Science, Elliptical galaxy, [SDU.ASTR.GA]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Galactic Astrophysics [astro-ph.GA], Astrophysics::Earth and Planetary Astrophysics, Astrophysics - Cosmology and Nongalactic Astrophysics
Abstract

We present observations of a very massive galaxy at z=1.82 which show that its morphology, size, velocity dispersion and stellar population properties that are fully consistent with those expected for passively evolving progenitors of today's giant ellipticals. These findings are based on a deep optical rest-frame spectrum obtained with the Multi-Object InfraRed Camera and Spectrograph (MOIRCS) on the Subaru telescope of a high-z passive galaxy candidate (pBzK) from the COSMOS field, for which we accurately measure its redshift of z=1.8230 and obtain an upper limit on its velocity dispersion sigma_star, ApJ Letters in press; 9 pages; 4 figures; 1 table; emulateapj.cls

Published
2010
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