The APOGEE-2 Survey of the Orion Star Forming Complex: I. Target
  Selection and Validation with early observations
  The Orion Star Forming Complex (OSFC) is a central target for the APOGEE-2
Young Cluster Survey. Existing membership catalogs span limited portions of the
OSFC, reflecting the difficulty of selecting targets homogeneously across this
extended, highly structured region. We have used data from wide field
photometric surveys to produce a less biased parent sample of young stellar
objects (YSOs) with infrared (IR) excesses indicative of warm circumstellar
material or photometric variability at optical wavelengths across the full 420
square degrees extent of the OSFC. When restricted to YSO candidates with H <
12.4, to ensure S/N ~100 for a six visit source, this uniformly selected sample
includes 1307 IR excess sources selected using criteria vetted by Koenig &
Liesawitz and 990 optical variables identified in the Pan-STARRS1 3$\pi$
survey: 319 sources exhibit both optical variability and evidence of
circumstellar disks through IR excess. Objects from this uniformly selected
sample received the highest priority for targeting, but required fewer than
half of the fibers on each APOGEE-2 plate. We fill the remaining fibers with
previously confirmed and new color-magnitude selected candidate OSFC members.
Radial velocity measurements from APOGEE-1 and new APOGEE-2 observations taken
in the survey's first year indicate that ~90% of the uniformly selected targets
have radial velocities consistent with Orion membership.The APOGEE-2 Orion
survey will include >1100 bona fide YSOs whose uniform selection function will
provide a robust sample for comparative analyses of the stellar populations and
properties across all sub-regions of Orion.
