1. The dominant role of mergers in the size evolution of massive early-type galaxies since z ~ 1
- Author
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Michele Moresco, Christian Maier, Lidia Tasca, J. F. Le Borgne, M. Mignoli, Laurence Tresse, Carrie Bridge, Daniela Vergani, Luke A. Barnes, Enrique Pérez-Montero, S. Bardelli, Herve Aussel, Masayuki Tanaka, Mara Salvato, S. de la Torre, C. Knobel, P. Franzetti, O. Le Fèvre, E. Ricciardelli, P. Kampczyk, M. Scodeggio, Angela Bongiorno, C. M. Carollo, O. Ilbert, Lucia Pozzetti, John D. Silverman, S. J. Lilly, Jean-Paul Kneib, Kevin Schawinski, H. J. McCracken, P. Nair, Anton M. Koekemoer, E. Zucca, C. K. Xu, David S Sanders, V. Presotto, K. Kovac, Thierry Contini, Roser Pello, Karina Caputi, C. López-Sanjuan, G. Zamorani, Yoshiaki Taniguchi, Niraj Welikala, Bianca Garilli, Y. Peng, F. Lamareille, Peter Capak, C. T. Liu, V. Le Brun, Graziano Coppa, Rongmon Bordoloi, L. de Ravel, A. Cappi, Micol Bolzonella, Alvio Renzini, Pascal Oesch, V. Mainieri, E. Le Floc'h, Olga Cucciati, A. Iovino, Andrea Cimatti, N. Z. Scoville, 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), C. Lopez-Sanjuan, O. Le Fevre, O. Ilbert, L. A. M. Tasca, C. Bridge, O. Cucciati, P. Kampczyk, L. Pozzetti, C. K. Xu, C. M. Carollo, T. Contini, J.-P. Kneib, S. J. Lilly, V. Mainieri, A. Renzini, D. Sander, M. Scodeggio, N. Z. Scoville, Y. Taniguchi, G. Zamorani, H. Aussel, S. Bardelli, M. Bolzonella, A. Bongiorno, P. Capak, K. Caputi, S. de la Torre, L. de Ravel, P. Franzetti, B. Garilli, A. Iovino, C. Knobel, K. Kovac, F. Lamareille, J.-F. Le Borgne, V. Le Brun, E. Le Floch, C. Maier, H. J. McCracken, M. Mignoli, R. Pello, Y. Peng, E. Perez-Montero, V. Presotto, E. Ricciardelli, M. Salvato, J. D. Silverman, M. Tanaka, L. Tresse, D. Vergani, E. Zucca, L. Barne, R. Bordoloi, A. Cappi, A. Cimatti, G. Coppa, A. Koekemoer, C. T. Liu, M. Moresco, P. Nair, P. Oesch, K. Schawinski, and N. Welikala
- Subjects
Physics ,Cosmology and Nongalactic Astrophysics (astro-ph.CO) ,010308 nuclear & particles physics ,Mass growth ,Velocity dispersion ,FOS: Physical sciences ,Astronomy and Astrophysics ,Astrophysics ,Astrophysics::Cosmology and Extragalactic Astrophysics ,01 natural sciences ,Galaxy ,Early type ,cD ,Space and Planetary Science ,0103 physical sciences ,galaxies: interactions ,[INFO]Computer Science [cs] ,galaxies: elliptical and lenticular ,galaxies: evolution ,[PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph] ,010303 astronomy & astrophysics ,ComputingMilieux_MISCELLANEOUS ,Astrophysics::Galaxy Astrophysics ,Astrophysics - Cosmology and Nongalactic Astrophysics - Abstract
In this paper we measure the merger fraction and rate, both minor and major, of massive early-type galaxies (M_star >= 10^11 M_Sun) in the COSMOS field, and study their role in mass and size evolution. We use the 30-band photometric catalogue in COSMOS, complemented with the spectroscopy of the zCOSMOS survey, to define close pairs with a separation 10h^-1 kpc = 1/4) and minor (1/10 = 1/10 mergers can explain ~55% of the observed size evolution of these galaxies since z ~ 1. Another ~20% is due to the progenitor bias (younger galaxies are more extended) and we estimate that very minor mergers (mu < 1/10) could contribute with an extra ~20%. The remaining ~5% should come from other processes (e.g., adiabatic expansion or observational effects). This picture also reproduces the mass growth and velocity dispersion evolution of these galaxies. We conclude from these results that merging is the main contributor to the size evolution of massive ETGs at z, Astronomy and Astrophysics, in press. 18 pages, 12 figures, 4 tables
- Published
- 2012
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