The zCOSMOS redshift survey: evolution of the light in bulges and discs since z similar to 0.8

L. A. M. Tasca (1) , L. Tresse (1) , O. Le Fèvre (1) , O. Ilbert (1) , S. J. Lilly (2) , G. Zamorani (3) , C. Lopez-Sanjuan (1) , L. C. Ho (4) , S. Bardelli (5) , A. Cattaneo (1) , O. Cucciati (6) , D. Farrah (7) , A. Iovino (8) , A. M. Koekemoer (9) , C. T. Liu (10) , R. Massey (11) , A. Renzini (12) , Y. Taniguchi (13) , N. Welikala , E. Zucca (5) , C. M. Carollo (14) , T. Contini (15) , J. -P. Kneib (16) , V. Mainieri (17) , M. Scodeggio (18) , M. Bolzonella (19) , A. Bongiorno (20) , K. Caputi (21) , S. de La Torre (1) , P. Franzetti , B. Garilli , L. Guzzo , P. Kampczyk , C. Knobel , K. Kovac , F. Lamareille (15) , J. -F. Le Borgne , V. Le Brun (1) , C. Maier (22) , M. Mignoli (3) , R. Pello (15) , Y. Peng (22) , E. Perez Montero (23) , Robert Michael Rich (24) , M. Tanaka (25) , D. Vergani (26) , R. Bordoloi (22) , A. Cappi (5) , Alessandro Cimatti (26) , G. Coppa (18) , H. J. Mccracken (27) , M. Moresco (5) , L. Pozzetti (19) , D. Sanders (28) , K. Sheth (29)

1 LAM - Laboratoire d'Astrophysique de Marseille
2 ETH Zürich - Eidgenössische Technische Hochschule - Swiss Federal Institute of Technology [Zürich]
3 INAF - Istituto Nazionale di Astrofisica
4 KIAA-PKU - Kavli Institute for Astronomy and Astrophysics [Beijing]
5 OABO - INAF - Osservatorio Astronomico di Bologna
6 Dipartimento di Fisica
7 Department of Physics [Blacksburg]
8 OAB - INAF - Osservatorio Astronomico di Brera
9 STSci - Space Telescope Science Institute
10 CUHK - City University of Hong Kong [Hong Kong]
11 ICC - Institute for Computational Cosmology
12 OAPD - INAF - Osservatorio Astronomico di Padova
13 RCSCE - Research Center for Space and Cosmic Evolution
14 University of Chicago
15 IRAP - Institut de recherche en astrophysique et planétologie
16 EPFL - Ecole Polytechnique Fédérale de Lausanne
17 ESO - European Southern Observatory
18 INAF- Milano
19 IASF-Bo - Istituto di Astrofisica Spaziale e Fisica cosmica - Bologna
20 MPE - Max-Planck-Institut für Extraterrestrische Physik
21 Kapteyn Astronomical Institute [Groningen]
22 Institute of Astronomy [ETH Zürich]
23 LATT - Laboratoire Astrophysique de Toulouse-Tarbes
24 Department of Physics and Astronomy [UCLA Los Angeles]
25 NAOJ - National Astronomical Observatory of Japan
26 OAA - INAF - Osservatorio Astrofisico di Arcetri
27 IAP - Institut d'Astrophysique de Paris
28 Institute for Astronomy [Honolulu]
29 NRAO - National Radio Astronomy Observatory

We studied the chronology of galactic bulge and disc formation by analysing the relative contributions of these components to the B-band rest-frame luminosity density at different epochs. We present the first estimate of the evolution of the fraction of rest-frame B-band light in galactic bulges and discs since redshift z similar to 0.8. We performed a bulge-to-disc decomposition of HST/ACS images of 3266 galaxies in the zCOSMOS-bright survey with spectroscopic redshifts in the range 0.7 \textless= z \textless= 0.9. We find that the fraction of B-band light in bulges and discs is (26 4)% and (74 4)%, respectively. When compared with rest-frame B-band measurements of galaxies in the local Universe in the same mass range (10(9)M circle dot M10(11.5).M circle dot),we find that the B-band light in discs decreases by -30% from z similar to 0.7-0.9 to z 0, while the light from the bulge increases by -30% over the same period of time. We interpret this evolution as the consequence of star formation and mass assembly processes, as well as morphological transformation, which gradually shift stars formed at half the age of the Universe from star-forming late-type/irregular galaxies to earlier types and ultimately into spheroids.

Mots clés: Galaxies: bulges; Galaxies: evolution; Galaxies: luminosity function; Mass function; Galaxies: distances and redshifts; Galaxies: fundamental parameters

Domaines: Astrophysique [astro-ph]

L. A. M. Tasca, L. Tresse, O. Le Fèvre, O. Ilbert, S. J. Lilly, et al.. The zCOSMOS redshift survey: evolution of the light in bulges and discs since z similar to 0.8. Astronomy and Astrophysics - A&A, 2014, 564, ⟨10.1051/0004-6361/201423699⟩. ⟨hal-01441999⟩