Abstract Details

Name: Omkar Suresh Bait
Affiliation: National Center for Radio Astrophysics-TIFR
Conference ID: ASI2017_671
Title : Star formation history of massive galaxies along the Hubble sequence
Authors and Co-Authors : Sudhanshu Barway (SAAO), Yogesh Wadadekar (NCRA-TIFR)
Abstract Type : Oral
Abstract Category : Extragalactic astronomy
Abstract : Using multiwavelength data, from UV-optical-IR, for ~7000 galaxies in the local Universe, we study the dependence of star formation history on the morphological T-types for massive galaxies (\log M_*/M_\odot \geq 10). We model the SED for each galaxy in our sample using broadband fluxes from GALEX-SDSS-2MASS-WISE and estimate the stellar mass and star formation rate of each galaxy. Since we have UV data from GALEX, we can put a better constraint on recent star formation in our sample of galaxies. As expected, we find that the late type spirals (Sc-Im morphologies) and ellipticals are mostly star forming and quenched, respectively. However, the early-type spirals (Sa-Sbc morphologies) and S0s are most interesting as they populate the green valley, which is a transition zone between the star forming and quenched region. In particular, we find that the fraction of early-type spirals decreases as we enter the green valley from the blue cloud, which coincides with the increase in the fraction of S0s. This points towards the morphological transformation of early-type spiral galaxies into S0s which can happen due to environmental effects such as ram-pressure stripping, galaxy harrasment, or tidal interactions. Interestingly, we also find a second population of S0s which are actively star-forming and are present in all environments, from low to high densities.