Fast Radio Bursts (FRBs) are a powerful and mysterious new class of transient
that are luminous enough to be detected at cosmological distances. By
associating FRBs to host galaxies, we can measure intrinsic and environmental
properties that test FRB origin models, in addition to using them as precise
probes of distant cosmic gas. The 110-antenna Deep Synoptic Array (DSA-110) is
a radio interferometer built to maximize the rate at which it can
simultaneously detect and localize FRBs. Here, we present the first sample of
FRBs and host galaxies discovered by the DSA-110. This sample of 11 FRBs is the
largest uniform sample of localized FRBs to date and is selected based on
association to host galaxies identified in optical imaging by Pan-STARRS1 and
follow-up spectroscopy at the Palomar and Keck observatories. These FRBs have
not been observed to repeat and their radio properties (dispersion, temporal
scattering, energy) are similar to that of the known non-repeating FRB
population. Most host galaxies have ongoing star formation, as has been
identified before for FRB hosts. In contrast to prior work, a large fraction
(four of eleven) of the new sample are more massive than 1011\ M⊙​
and most had elevated star formation rates more than 100 Myr in their past. The
distribution of star-formation history across this host-galaxy sample shows
that the delay-time distribution is wide, spanning from ∼100\,Myr to
∼10\,Gyr. This requires the existence of one or more progenitor formation
channels associated with old stellar populations, such as the binary evolution
of compact objects.Comment: 21 pages. Submitted to AAS Journal