Inner and outer star forming regions over the disks of spiral galaxies I. Sample characterization
Por:
Rodriguez-Baras, M., Diaz, A. I., Rosales-Ortega, F. F., Sanchez, S. F.
Publicada:
23 ene 2018
Resumen:
Context. The knowledge of abundance distributions is central to
understanding the formation and evolution of galaxies. Most of the
relations employed for the derivation of gas abundances have so far been
derived from observations of outer disk H II regions, despite the known
differences between inner and outer regions.
Aims. Using integral field spectroscopy (IFS) observations we aim to
perform a systematic study and comparison of two inner and outer H II
regions samples. The spatial resolution of the IFS, the number of
objects and the homogeneity and coherence of the observations allow a
complete characterization of the main observational properties and
differences of the regions.
Methods. We analyzed a sample of 725 inner H II regions and a sample of
671 outer H II regions, all of them detected and extracted from the
observations of a sample of 263 nearby, isolated, spiral galaxies
observed by the CALIFA survey.
Results. We find that inner H II regions show smaller equivalent widths,
greater extinction and luminosities, along with greater values of [N
II] lambda 6583/H alpha and [O II] lambda 3727/[O III] lambda 5007
emission-line ratios, indicating higher metallicities and lower
ionization parameters. Inner regions have also redder colors and higher
photometric and ionizing masses, although M-ion/M-phot is slighty higher
for the outer regions.
Conclusions. This work shows important observational differences between
inner and outer H II regions in star forming galaxies not previously
studied in detail. These differences indicate that inner regions have
more evolved stellar populations and are in a later evolution state with
respect to outer regions, which goes in line with the inside-out galaxy
formation paradigm.
Filiaciones:
Rodriguez-Baras, M.:
Univ Autonoma Madrid, Dept Fis Teor, E-28049 Madrid, Spain
Diaz, A. I.:
Univ Autonoma Madrid, Dept Fis Teor, E-28049 Madrid, Spain
Rosales-Ortega, F. F.:
Inst Nacl Astrofis Opt & Electr, Luis E Erro 1, Tonantzintla 72840, Puebla, Mexico
Sanchez, S. F.:
Univ Nacl Autonoma Mexico, Inst Astron, AP 70-264, Mexico City 04510, DF, Mexico
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