Using high resolution spectra from the VLT LEGA-C program , we reconstruct the star formation histories ( SFHs ) of 607 galaxies at redshifts z = 0.6 - 1.0 and stellar masses \gtrsim 10 ^ { 10 } M _ { \odot } using a custom full spectrum fitting algorithm that incorporates the emcee and FSPS packages .
We show that the \added mass-weighted age of a galaxy correlates strongly with stellar velocity dispersion ( \sigma _ { * } ) and ongoing star-formation ( SF ) activity , with the stellar content in higher- \sigma _ { * } galaxies having formed earlier and faster .
The SFHs of quiescent galaxies are generally consistent with passive evolution since their main SF epoch , but a minority show clear evidence of a rejuvenation event in their recent past .
The mean age of stars in galaxies that are star-forming is generally significantly younger , with SF peaking after z < 1.5 for almost all star-forming galaxies in the sample : many of these still have either constant or rising SFRs on timescales > 100 Myrs .
This indicates that z > 2 progenitors of z \sim 1 star-forming galaxies are generally far less massive .
Finally , despite considerable variance in the individual SFHs , we show that the current SF activity of massive galaxies ( > L _ { * } ) at z \sim 1 correlates with SF levels at least 3 Gyrs prior : SFHs retain ‘ memory ’ on a large fraction of the Hubble time .
Our results illustrate a novel approach to resolve the formation phase of galaxies , and in identifying their individual evolutionary paths , connects progenitors and descendants across cosmic time .
This is uniquely enabled by the high-quality continuum spectroscopy provided by the LEGA-C survey .