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Título del libro: Proceedings Of The 12th Scientific Meeting Of The Spanish Astronomical Society - Highlights Of Spanish Astrophysics Ix, Sea 2016
Título del capítulo: The CALIFA connection between outer-disk reddening and gas-phase metallicities

Autores UNAM:
SEBASTIAN FRANCISCO SANCHEZ SANCHEZ;
Autores externos:

Idioma:

Año de publicación:
2016
Palabras clave:

Astrophysics; Color; Galaxies; Gases; Luminance; Oxygen; Surveys; Color gradients; Different mechanisms; Evolution of galaxies; Exponential law; Formation and evolutions; Gradient distributions; Sloan Digital Sky Survey; Surface brightness; Ionization of gases


Resumen:

In Marino et al. 2016 we investigate, for the first time in a statistically significant and well-defined sample, the behavior of the colors and of the oxygen abundance from HII regions located within and beyond the break radius in the surface brightness profiles. We perform a detailed light-profile classification using Sloan Digital Sky Survey (SDSS) g-and r-band surface brightness, (g'-r') color, as well we characterize the ionized-gas oxygen abundance profiles for 350 galaxies within Calar Alto Legacy Integral Field Area (CALIFA) Survey. Our main results are: (i) We find that about 84% of our disks show clear down-or up-bending profiles (Type ii and Type iii, respectively) while the remaining 16% are well fitted by one single exponential law (Type i); (ii) The analysis of the color gradients reveals a U-shape profile for the Type ii galaxies with a minimum (g'-r') color of ~0.5 mag; (iii) We find a statistically significant signal of flattening in the outer ionized-gas metallicities, associated with the difference in the outer-to-inner disk gradient distribution. We discuss the relation between the outer-disk ionized-gas metallicity gradients and the presence of breaks in the surface brightness profiles of disk galaxies in the context of the evolution of galaxy disks and we propose different mechanism(s) that could have driven the formation and evolution of the galaxies' outskirts and, in particular, the reddening of the stellar colors found in these peripherical regions. © 2016 Proceedings of the 12th Scientific Meeting of the Spanish Astronomical Society - Highlights of Spanish Astrophysics IX, SEA 2016. All rights reserved.


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