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

TL;DR

This study extends an 86 GHz SiO maser survey of late-type stars in the Inner Galaxy, detecting 92 sources and analyzing infrared data to characterize the stellar populations in the Scutum and Sagittarius-Carina arms.

Contribution

It provides new SiO maser detections for late-type stars in the specified Galactic regions and confirms the stellar types using infrared color analysis.

Findings

Detected 92 SiO maser sources, 86 of which are new.

Most targets are oxygen-rich AGB stars, with minimal carbon star contamination.

The detection rate remains consistent at 68% across the extended survey.

Abstract

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%.