COOL-LAMPS II. Characterizing the Size and Star Formation History of a
  Bright Strongly Lensed Early-Type Galaxy at Redshift 1.02
  We present COOL J1323+0343, an early-type galaxy at $z = 1.0153 \pm 0.0006$,
strongly lensed by a cluster of galaxies at z = $z = 0.353 \pm 0.001$. This
object was originally imaged by DECaLS and noted as a gravitational lens by
COOL-LAMPS, a collaboration initiated to find strong-lensing systems in recent
public optical imaging data, and confirmed with follow-up data. With
ground-based grzH imaging and optical spectroscopy from the Las Campanas
Observatory and the Nordic Optical Telescope, we derive a stellar mass,
metallicity, and star-formation history from stellar-population synthesis
modeling. The lens modeling implies a total magnification of $\mu \sim $113.
The median remnant stellar mass in the source plane is M$_* \sim 10.63$
$M_\odot$ and the median star-formation rate in the source plane is SFR $\sim
1.55 \times 10^{-3}$ M$_\odot$ yr$^{-1}$ (log sSFR = -13.4 yr$^{-1}$) in the
youngest two age bins (0-100 Myr), closest to the epoch of observation. Our
measurements place COOL J1323+0343 below the characteristic mass of the stellar
mass function, making it an especially compelling target that could help
clarify how intermediate mass quiescent galaxies evolve. We reconstruct COOL
J1323+0343 in the source plane and fit its light profile. This object is below
the expected size-evolution of early-type galaxy at this mass with an effective
radius r$_e \sim$ 0.5 kpc. This extraordinarily magnified and bright lensed
early-type galaxy offers an exciting opportunity to study the morphology and
star formation history of an intermediate mass early-type galaxy in detail at
$z \sim $1 .
