The star formation history of CALIFA galaxies: Radial structures

Autor(en)

R. M. González Delgado, E. Pérez, R. Cid Fernandes, R. García-Benito, A. L. 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., Jr. Kennicutt, D. Kupko, M. Lyubenova, D. Mast, M. Mollá, R. A. Marino, A. Quirrenbach, J. M. Vílchez, L. Wisotzki,

Abstrakt

We study the radial structure of the stellar mass surface density

($\mu$) 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 use the fossil record to recover the star formation history (SFH) in

spheroidal and disk dominated galaxies with masses from 10$^9$ to

10$^{12}$ M$_\odot$. We derive the half mass radius, and we find that

galaxies are on average 15% more compact in mass than in light. HMR/HLR

decreases with increasing mass for disk galaxies, but is almost constant

in spheroidal galaxies. We find that the galaxy-averaged stellar

population age, stellar extinction, and $\mu$ are well represented by

their values at 1 HLR. Negative radial gradients of the stellar

population ages support an inside-out formation. The larger inner age

gradients occur in the most massive disk galaxies that have the most

prominent bulges; shallower age gradients are obtained in spheroids of

similar mass. Disk and spheroidal galaxies show negative $\mu$ gradients

that steepen with stellar mass. In spheroidal galaxies $\mu$ saturates

at a critical value that is independent of the galaxy mass. Thus, all

the massive spheroidal galaxies have similar local $\mu$ at the same

radius (in HLR units). The SFH of the regions beyond 1 HLR are well

correlated with their local $\mu$, and follow the same relation as the

galaxy-averaged age and $\mu$; suggesting 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

$\mu$. Thus, galaxy mass is a more fundamental property in spheroidal

systems while the local stellar mass surface density is more important

in disks.

Organisation(en)

Institut für Astrophysik

Externe Organisation(en)

Max-Planck-Institut für Astronomie

Publikationsdatum

10-2013

ÖFOS 2012

103003 Astronomie

Schlagwörter

Link zum Portal

https://ucrisportal.univie.ac.at/de/publications/adf7ee20-7eae-4dc3-93aa-1f9baa219022