  We describe a method that exploits data from the GALEX ultraviolet and WISE
and 2MASS infrared source catalogs, combined with proper motions and empirical
pre-main sequence isochrones, to identify candidate nearby, young, low-mass
stars. Applying our method across the full GALEX- covered sky, we identify 2031
mostly M-type stars that, for an assumed age of 10 (100) Myr, all lie within
~150 (~90) pc of Earth. The distribution of M spectral subclasses among these
~2000 candidate young stars peaks sharply in the range M3-M4; these subtypes
constitute 50% of the sample, consistent with studies of the M star population
in the immediate solar neighborhood. We focus on a subset of 58 of these
candidate young M stars in the vicinity of the Tucana-Horologium Association.
Only 20 of these 58 candidates were detected in the ROSAT All-Sky X-ray Survey
-- reflecting the greater sensitivity of GALEX for purposes of identifying
active nearby, young stars, particularly for stars of type M4 and later. Based
on statistical analysis of the kinematics and/or spectroscopic followup of
these 58 M stars, we find that 50% (29 stars) indeed have properties consistent
with Tuc-Hor membership, while 12 are potential new members of the Columba
Association, and two may be AB Dor moving group members. Hence, ~75% of our
initial subsample of 58 candidates are likely members of young (age ~10-40 Myr)
stellar moving groups within 100 pc, verifying that the stellar color- and
kinematics-based selection algorithms described here can be used to efficiently
isolate nearby, young, low-mass objects from among the field star population.
Future studies will focus on characterizing additional subsamples selected from
among this list of candidate nearby, young M stars.
