The star formation history of CALIFA galaxies: Radial structures

Author(s)

R. M. González Delgado, Enrique Pérez, R. Cid Fernandes, R. García-Benito, André Luiz de Amorim, S. F. Sánchez, B. Husemann, C. Cortijo-Ferrero, R. López Fernández, P. Sánchez-Blázquez, S. Bekeraite, C. J. Walcher, J. Falcón-Barroso, A. Gallazzi, G. van de Ven, J. Alves, J. Bland-Hawthorn, R. C. Kennicutt, D. Kupko, M. Lyubenova, D. Mast, M. Mollá, R. A. Marino, A. Quirrenbach, J. M. Vílchez, L. Wisotzki

Abstract

We have studied the radial structure of the stellar mass surface density

(μ∗) and stellar population age as a function of

the total stellar mass and morphology for a sample of 107 galaxies from

the CALIFA survey. We applied the fossil record method based on spectral

synthesis techniques to recover the star formation history (SFH),

resolved in space and time, in spheroidal and disk dominated galaxies

with masses from 109 to 1012 M⊙. We

derived the half-mass radius, and we found that galaxies are on average

15% more compact in mass than in light. The ratio of half-mass radius to

half-light radius (HLR) shows a dual dependence with galaxy stellar

mass; it decreases with increasing mass for disk galaxies, but is almost

constant in spheroidal galaxies. In terms of integrated versus spatially

resolved properties, we find that the galaxy-averaged stellar population

age, stellar extinction, and μ∗ are well

represented by their values at 1 HLR. Negative radial gradients of the

stellar population ages are present in most of the galaxies, supporting

an inside-out formation. The larger inner (≤1 HLR) age gradients

occur in the most massive (1011 M⊙) disk

galaxies that have the most prominent bulges; shallower age gradients

are obtained in spheroids of similar mass. Disk and spheroidal galaxies

show negative μ∗ gradients that steepen with

stellar mass. In spheroidal galaxies, μ∗ saturates

at a critical value (~7 × 102

M⊙/pc2 at 1 HLR) that is independent of the

galaxy mass. Thus, all the massive spheroidal galaxies have similar

local μ∗ at the same distance (in HLR units) from

the nucleus. The SFH of the regions beyond 1 HLR are well correlated

with their local μ∗, and follow the same relation

as the galaxy-averaged age and μ∗; this suggests

that local stellar mass surface density preserves the SFH of disks. The

SFH of bulges are, however, more fundamentally related to the total

stellar mass, since the radial structure of the stellar age changes with

galaxy mass even though all the spheroid dominated galaxies have similar

radial structure in μ∗. Thus, galaxy mass is a more

fundamental property in spheroidal systems, while the local stellar mass

surface density is more important in disks.

 

Table 1 and appendices are available in electronic form at www.aanda.org

Organisation(s)

Department of Astrophysics

External organisation(s)

Centro de Investigaciones Energeticas Medioambientales y Tecnológica, Max-Planck-Institut für Astronomie, The University of Sydney, Universidade Federal de Santa Catarina, University of Cambridge, Instituto de Astrofísica de Andalucía (CSIC), INAF - Osservatorio Astrofisico di Arcetri, Leibniz-Institut für Astrophysik Potsdam, Universidad Autónoma de Madrid, Institute of Astrophysics of the Canary Islands, University of La Laguna, University of Copenhagen, Landessternwarte Königstuhl (LSW)

Journal

Astronomy & Astrophysics

Volume

562

No. of pages

25

ISSN

0004-6361

DOI

https://doi.org/10.1051/0004-6361/201322011

Publication date

02-2014

Peer reviewed

Yes

Austrian Fields of Science 2012

103003 Astronomy, 103004 Astrophysics

Keywords

ASJC Scopus subject areas

Astronomy and Astrophysics, Space and Planetary Science

Portal url

https://ucrisportal.univie.ac.at/en/publications/47f9f64e-c2d3-488c-a3e1-6ad629e7bf9d