Bibcode
Sánchez, S. F.; Rosales-Ortega, F. F.; Iglesias-Páramo, J.; Mollá, M.; Barrera-Ballesteros, J.; Marino, R. A.; Pérez, E.; Sánchez-Blazquez, P.; González Delgado, R.; Cid Fernandes, R.; de Lorenzo-Cáceres, A.; Méndez-Abreu, J.; Galbany, L.; Falcon-Barroso, J.; Miralles-Caballero, D.; Husemann, B.; García-Benito, R.; Mast, D.; Walcher, C. J.; Gil de Paz, A.; García-Lorenzo, B.; Jungwiert, B.; Vílchez, J. M.; Jílková, Lucie; Lyubenova, M.; Cortijo-Ferrero, C.; Díaz, A. I.; Wisotzki, L.; Márquez, I.; Bland-Hawthorn, J.; Ellis, S.; van de Ven, G.; Jahnke, K.; Papaderos, P.; Gomes, J. M.; Mendoza, M. A.; López-Sánchez, Á. R.
Bibliographical reference
Astronomy and Astrophysics, Volume 563, id.A49, 25 pp.
Advertised on:
3
2014
Journal
Citations
421
Refereed citations
382
Description
We present the largest and most homogeneous catalog of H ii regions and
associations compiled so far. The catalog comprises more than 7000
ionized regions, extracted from 306 galaxies observed by the CALIFA
survey. We describe the procedures used to detect, select, and analyze
the spectroscopic properties of these ionized regions. In the current
study we focus on characterizing of the radial gradient of the oxygen
abundance in the ionized gas, based on the study of the
deprojecteddistribution of H ii regions. We found that all galaxies
without clear evidence of an interaction present a common gradient in
the oxygen abundance, with a characteristic slope of
αO/H = -0.1 dex/re between 0.3 and 2 disk
effective radii (re), and a scatter compatible with random
fluctuations around this value, when the gradient is normalized to the
disk effective radius. The slope is independent of morphology, the
incidence of bars, absolute magnitude, or mass. Only those galaxies with
evidence of interactions and/or clear merging systems present a
significantly shallower gradient, consistent with previous results. The
majority of the 94 galaxies with H ii regions detected beyond two disk
effective radii present a flattening in the oxygen abundance. The
flattening is statistically significant. We cannot provide a conclusive
answer regarding the origin of this flattening. However, our results
indicate that its origin is most probably related to the secular
evolution of galaxies. Finally, we find a drop/truncation of the oxygen
abundance in the inner regions for 26 of the galaxies. All of them are
non-interacting, mostly unbarred Sb/Sbc galaxies. This feature is
associated with a central star-forming ring, which suggests that both
features are produced by radial gas flows induced by resonance
processes. Our result suggests that galaxy disks grow inside-out, with
metal enrichment driven by the local star formation history and with a
small variation galaxy-by-galaxy. At a certain galactocentric distance,
the oxygen abundance seems to be correlated well with the stellar mass
density and total stellar mass of the galaxies, independently of other
properties of the galaxies. Other processes, such as radial mixing and
inflows/outflows seem to have a limited effect on shaping of the radial
distribution of oxygen abundances, although they are not ruled out.
Appendices are available in electronic form at http://www.aanda.orgBased
on observations collected at the Centro Astronómico Hispano
Alemán (CAHA) at Calar Alto, operated jointly by the Max-Planck
Institut für Astronomie and the Instituto de Astrofísica de
Andalucía (CSIC).
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