86 GHz SiO maser survey of late-type stars in the Inner Galaxy. IV. SiO
  emission and infrared data for sources in the Scutum and Sagittarius-Carina
  arms, 20 deg < l < 50 deg
  We present an 86 GHz SiO (v = 1, J = 2 ---> 1) maser search toward late-type
stars located within |b|<0.5 deg and 20 deg < l < 50 deg. This search is an
extension at longer longitudes of a previously published work. We selected 135
stars from the MSX catalog using color and flux criteria and detected 92 (86
new detections). The detection rate is 68%, the same as in our previous study.
  The last few decades have seen the publication of several catalogs of point
sources detected in infrared surveys (MSX, 2MASS, DENIS, ISOGAL, WISE, GLIMPSE,
AKARI, and MIPSGAL). We searched each catalog for data on the 444 targets of
our earlier survey and for the 135 in the survey reported here. We confirm
that, as anticipated, most of our targets have colors typical of oxygen-rich
asymptotic giant branch (AGB) stars. Only one target star may have already left
the AGB. Ten stars have colors typical of carbon-rich stars, meaning a
contamination of our sample with carbon stars <=1.7%.
