Speaker
Abdurrouf Abdurrouf
(Astronomical Institute, Tohoku University)
Description
According to Lambda CDM paradigm of hierarchical galaxy formation, galactic disks
were form gradually from inside to outside (“inside-out” scenario of galaxy
formation). In spite of this being a long-known prediction, but very few
observational evidences have been brought forward to support it. In order to sought
the indication of this “inside-out” scenario in the local universe and also to test
it, in this research the distribution of SFR and stellar mass of 118 local massive
spiral galaxies (with log(M*)>10.5 located at 0.01<z<0.02) are resolved. The method
so called “pixel-to-pixel SED fitting” is established to obtained the resolved SFR
and stellar mass of galaxy by fitting observed resolved-7bands photometric SEDs
(using data from GALEX and SDSS) with set of constructed Model SEDs. Fitting is done
by using Bayesian Inference statistic. Analysis on resolved SFRs and stellar masses
of galaxies sample found that SFR distribution in the galaxy is typically follow
stellar mass distribution but more extended (as expected from "inside-out" scenario);
sSFR radial profiles are relatively flat in the outskirt but suppressed in the
central region (indication of inside-out quenching); majority of galaxies have total
SFR outside (of half-mass radius) larger than total SFR inside (of half-mass radius),
and majority of those which have large ratio of total SFR outside/total SFR inside
are bar galaxies. We also found that bar structure in galaxies suppress SFR around
it. In addition to this results, we also found the indication of resolved
"Downsizing" scenario, where more massive galaxies tend to be quenched faster in all
radii than less massive galaxies; and the consistency between integrated and resolved
star formation main sequence (SFMS) which indicates that integrated SFMS might be
derived from local SFMS relation. Overall, this results confirm the inside-out
scenario of disk galaxies formation.
Primary author
Abdurrouf Abdurrouf
(Astronomical Institute, Tohoku University)
Co-author
Masayuki Akiyama
(Astronomical Institute, Tohoku University)
