Bibcode
Lara-López, M. A.; Bongiovanni, A.; Cepa, J.; Pérez-García, A. M.; Sánchez-Portal, M.; Castañeda, H. O.; Fernández-Lorenzo, M.; Pović, M.
Referencia bibliográfica
Astronomy and Astrophysics, Volume 519, id.A31
Fecha de publicación:
9
2010
Revista
Número de citas
71
Número de citas referidas
66
Descripción
Context. To understand the formation and evolution of galaxies, it is
important to have a full comprehension of the role played by
metallicity, star formation rate (SFR), morphology, and color. The
interplay of these parameters at different redshifts will substantially
affect the evolution of galaxies and, as a consequence, their evolution
provides important clues and constraints for the galaxy evolution
models. Aims: In this work we focus on the evolution of the SFR,
metallicity of the gas, and morphology of galaxies at low redshift in
search of signs of evolution. We analyzed the evolution of the SFR,
metallicity, and morphology, through the mass-metallicity,
luminosity-metallicity, SFR-stellar mass, and SFR-metallicity
relationships of star-forming galaxies from SDSS-DR5 (Sloan Digital Sky
Survey-Data Release 5), using redshift intervals in bins of 0.1 from ~0
to 0.4. Methods: We used data processed with the STARLIGHT
spectral synthesis code, correcting the fluxes for dust extinction, and
estimating metallicities using the R23 method. We used the
S2N2 (log(Hα/[S ii]) vs. log(Hα/[N ii])) diagnostic diagram
as a tool to classify star-forming, composite, and AGN galaxies. We
analyzed the evolution of the three principal BPT diagrams, estimating
the SFR and specific SFR (SSFR) for our samples of galaxies, studying
the luminosity and mass-metallicity relations, and analyzing the
morphology of our sample of galaxies through the g-r color,
concentration index, and SSFR. Results: We found that the S2N2 is
a reliable diagram for classifying star-forming, composite, and AGNs
galaxies. We demonstrate that the three principal BPT diagrams show an
evolution toward higher values of [O iii] λ5007/Hβ due to a
metallicity decrement. We found an evolution in the mass-metallicity
relation of ~0.2 dex for the redshift range 0.3 < z < 0.4 compared
to our local one. From the analysis of the evolution of the SFR and SSFR
as a function of the stellar mass and metallicity, we discovered a group
of galaxies with higher SFR and SSFR at all redshift samples, whose
morphology is consistent with those of late-type galaxies. Finally, the
comparison of our local (0.04 < z < 0.1) with our higher redshift
sample (0.3 < z < 0.4) shows that the metallicity, the SFR, and
morphology evolve toward lower values of metallicity, higher SFRs, and
late-type morphologies for the redshift range 0.3 < z < 0.4.