Using high resolution spectra from the VLT LEGA-C program, we reconstruct thestar formation histories (SFHs) of 607 galaxies at redshifts $z = 0.6-1.0$ andstellar masses $\gtrsim10^{10}$M$_{\odot}$ using a custom full spectrum fittingalgorithm that incorporates the emcee and FSPS packages. We show that themass-weighted age of a galaxy correlates strongly with stellar velocitydispersion ($\sigma_*$) and ongoing star-formation (SF) activity, with thestellar content in higher-$\sigma_*$ galaxies having formed earlier and faster.The SFHs of quiescent galaxies are generally consistent with passive evolutionsince their main SF epoch, but a minority show clear evidence of a rejuvenationevent in their recent past. The mean age of stars in galaxies that arestar-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 haveeither constant or rising SFRs on timescales $>100$Myrs. This indicates that$z>2$ progenitors of $z\sim1$ star-forming galaxies are generally far lessmassive. Finally, despite considerable variance in the individual SFHs, we showthat the current SF activity of massive galaxies ($>$L$_*$) at $z\sim1$correlates with SF levels at least $3$Gyrs prior: SFHs retain `memory' on alarge fraction of the Hubble time. Our results illustrate a novel approach toresolve the formation phase of galaxies, and in identifying their individualevolutionary paths, connects progenitors and descendants across cosmic time.This is uniquely enabled by the high-quality continuum spectroscopy provided bythe LEGA-C survey.

A decade of study has established that the molecular gas properties ofstar-forming galaxies follow coherent scaling relations out to z~3, suggestingremarkable regularity of the interplay between molecular gas, star formation,and stellar growth. Passive galaxies, however, are expected to be gas-poor andtherefore faint, and thus little is known about molecular gas in passivegalaxies beyond the local universe. Here we present deep Atacama LargeMillimeter/submillimeter Array (ALMA) observations of CO(2-1) emission in 8massive (Mstar ~ 10^11 Msol) galaxies at z~0.7 selected to lie a factor of 3-10below the star-forming sequence at this redshift, drawn from the Large EarlyGalaxy Astrophysics Census (LEGA-C) survey. We significantly detect half thesample, finding molecular gas fractions <~0.1. We show that the molecular andstellar rotational axes are broadly consistent, arguing that the molecular gaswas not accreted after the galaxies became quiescent. We find that scalingrelations extrapolated from the star-forming population over-predict both thegas fraction and gas depletion time for passive objects, suggesting theexistence of either a break or large increase in scatter in these relations atlow specific star formation rate. Finally, we show that the gas fractions ofthe passive galaxies we have observed at intermediate redshifts are naturallyconsistent with evolution into local massive early-type galaxies by continuedlow-level star formation, with no need for further gas accretion or dynamicalstabilization of the gas reservoirs in the intervening 6 billion years.

The process by which massive galaxies transition from blue, star-formingdisks into red, quiescent galaxies remains one of the most poorly-understoodaspects of galaxy evolution. In this investigation, we attempt to gain a betterunderstanding of how star formation is quenched by focusing on a massivepost-starburst galaxy at z = 0.747. The target has a high stellar mass and amolecular gas fraction of ~30% -- unusually high for its low star formationrate. We look for indicators of star formation suppression mechanisms in thestellar kinematics and age distribution of the galaxy obtained from spatiallyresolved Gemini Integral-Field spectra and in the gas kinematics obtained fromALMA. We find evidence of significant rotation in the stars, but we do notdetect a stellar age gradient within 5 kpc. The molecular gas is aligned withthe stellar component, and we see no evidence of strong gas outflows. Ourtarget may represent the product of a merger-induced starburst or ofmorphological quenching; however, our results are not completely consistentwith any of the prominent quenching models.