The Discovery of QSOs Behind M31 and M33
  We report the discovery of 11 newly found quasars behind the stellar disks of
the spiral galaxies M31 and M33 in the fields covered by the Local Group Galaxy
Survey. Their redshifts range from 0.37 to 2.15. Most are X-ray, UV, and IR
sources. We also report the discovery of 5 normal background galaxies. Most of
these objects were observed owing to their anomalous colors, as part of a
program (reported elsewhere) to confirm spectroscopically candidate red
supergiant plus B star binaries; others were discovered as part of our
identification of early-type massive stars based upon their optical colors.
There are 15 previously known quasars in the same fields, for a grand total of
26, 15 behind M31 and 11 behind M33. Of these, only eight were discovered as
part of surveys for quasars; the rest were found accidentally. The quasars are
well distributed in the M31 and M33 fields, except for the inner regions, and
have the potential for being good probes of the interstellar medium in these
stellar disks, as well as serving as zero-point calibrators for Gaia
parallaxes.
