2018/03/07 by Eduardo Telles, Jorge Melnick
Physics and Astronomy · #Astronomy #Astronomy and Astrophysical Research #Astrophysics #Galaxies: Formation, Evolution, Phenomena #Galaxy #Photometry (optics) #Physics #Spectral energy distribution #Star formation #Stars #Stellar mass #Stellar population #Stellar, planetary, and galactic studies #astro-ph.GA
paper · pdf · doi:10.1051/0004-6361/201732275
published as A&A 615, A55 (2018) · 12 pages, 14 Figures, Accepted for publication in Astronomy & Astrophysics
arxiv created 2018/03/07 · openalex publication_date 2018/03/26 · arxiv updated 2021/02/18 · openalex created_date 2022/08/04 · openalex updated_date 2026/06/11
Aims. We present a UV to mid-IR spectral energy distribution (SED) study of a large sample of SDSS DR13 HII galaxies. These galaxies are selected as starbursts (EW(H α ) > 50Å) and for their high-excitation locus in the upper left region of the BPT diagram. Their photometry was derived from the cross-matched GALEX, SDSS, UKDISS, and WISE catalogs. Methods. We used CIGALE modeling and a SED fitting routine with the parametrization of a three-burst star formation history, and a comprehensive analysis of all other model parameters. We were able to estimate the contribution of the underlying old stellar population to the observed equivalent width of H β , and allow for more accurate burst age determination. Results. We found that the star formation histories of HII Galaxies can be reproduced remarkably well by three major eras of star formation. In addition, the SED fitting results indicate that in all cases the current burst produces a small percent of the total stellar mass, i.e., the bulk of stellar mass in HII galaxies has been produced by the past episodes of star formation, and also indicate that at a given age the H β luminosity depends only on the mass of young stars favoring a universal IMF for massive stars. Most importantly, the current star formation episodes are maximum starbursts that produce stars at the highest possible rate.