The Grism Lens-amplified Survey from Space (GLASS). XII. Spatially Resolved Galaxy Star Formation Histories and True Evolutionary Paths at z > 1

摘要: Modern data empower observers to describe galaxies as the spatially and biographically complex objects they are. We illustrate this through case studies of four, $z\sim1.3$ systems based on deep, resolved, 17-band + G102 G141 Hubble Space Telescope grism spectrophotometry. Using full spectrum rest-UV/-optical continuum fitting, we characterize these galaxies' observed $\sim$kpc-scale structures star formation rates (SFRs) reconstruct their history over age universe. The sample's diversity---passive vigorously starforming; stellar masses $\log M_*/M_\odot=10.5$ $11.2$---enables us draw spatio-temporal inferences relevant key areas parameter space (Milky Way- super-Andromeda-mass progenitors). Specifically, find signs that bulge mass-fractions ($B/T$) SF shapes/spatial uniformity are linked, such higher $B/T$s correlate with "inside-out growth" central specific SFRs peaked above global average for all starforming at epoch. Conversely, system lowest $B/T$ had a flat, uniform SFH normal peak activity. Both findings consistent models positing feedback-driven connection between switch from rising falling ("quenching"). While sample size forces conclusion remain tentative, work provides proof-of-concept future efforts refine or refute it: JWST, WFIRST, 30-m class telescopes will routinely produce amenable more sophisticated analyses. These samples---spanning representative mass, redshift, SFR, environmental regimes---will be ripe converting into thousands sub-galactic-scale empirical windows what individual actually looked like in past, ushering new dialog observation theory.