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° <  l <  50°^⋆

¹ Key Laboratory for Researches in Galaxies and Cosmology, University of Science and Technology of China, Chinese Academy of Sciences, Hefei, Anhui, 230026 PR China
e-mail: messineo@ustc.edu.cn
² Leiden Observatory, PO Box 9513 2300 RA Leiden, The Netherlands
³ National Radio Astronomy Observatory, PO Box 0 Socorro NM, 87801 USA
⁴ Institut d’Astrophysique de Paris CNRS, 98bis Boulevard Arago, 75014 Paris, France
⁵ Max-Planck-Institut für Radioastronomie, Auf dem Hügel 69, 53121 Bonn, Germany

Received: 1 March 2017
Accepted: 11 May 2018

Abstract

We present an 86 GHz SiO (v = 1,  J = 2 → 1) maser search toward late-type stars located within |b|< 0.​​°5 and 20° <  l <  50°. 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%.