Galactic Kinematics and Observed Flare Rates of a Volume-Complete Sample
  of Mid-to-Late M-dwarfs: Constraints on the History of the Stellar Radiation
  Environment of Planets Orbiting Low-mass Stars
  We present a study of the relationship between galactic kinematics, flare
rates, chromospheric magnetic activity, and rotation periods for a
volume-complete, nearly all-sky sample of 219 single stars within 15 parsecs
and with masses between 0.1$-$0.3 M$\odot$ observed during the primary mission
of TESS. We find that all targeted stars are consistent with a common value of
$\alpha$=1.984 $\pm$ 0.019 for the exponent of the flare frequency
distribution. From multi-epoch high-resolution spectroscopy, we determine the
stellar radial velocity which, when combined with Gaia astrometry, permits us
to determine the galactic UVW space motions. We find that 64% of our stars are
members of the thin disk in the Galaxy, 5% belong to the thick disk, and for
the remaining 31%, we cannot confidently assign membership to either component.
If we assume that star formation has been constant in the thin disk for the
past 8 Gyr, then based on the fraction that we observe to be active, we
estimate the average age at which these stars transition from the saturated to
the unsaturated flaring regime to be 2.4 $\pm$ 0.3 Gyr. This is consistent with
the ages that we assign from galactic kinematics: We find that stars with Prot
$<$ 10 days (which have yet to spin down) have a mean age of 2.0 $\pm$ 1.2 Gyr,
whereas stars with 10 $<$ Prot $\leq$ 90 days have a mean age of 5.6 $\pm$ 2.7
Gyr, and stars with Prot $>$ 90 days have a mean age of 12.9 $\pm$ 3.5 Gyr.
When we divide our sample by mass, we find that the average age of stars with
Prot $<$ 10 days increases from 0.6 $\pm$ 0.3 Gyr (0.2 - 0.3 M$\odot$) to 2.3
$\pm$ 1.3 Gyr (0.1--0.2 M$\odot$).
