Multiline observations of S255IR with ALMA

TL;DR

This paper reports high-resolution ALMA observations of the S255IR star-forming region, revealing detailed molecular line data, source structure, kinematics, and a novel methanol maser line detection.

Contribution

It provides new high-resolution spectral and spatial data of S255IR, including the discovery of a previously unpredicted methanol maser line.

Findings

Detection of multiple molecular lines including C$^{34}$S, CH$_3$CN, CO, SiO.

Sample spectra and maps illustrating source structure.

Discovery of a new methanol maser line.

Abstract

We present preliminary results of the high resolution $ (0.10^{\prime\prime} \times 0.15^{\prime\prime}) $ observations of the high mass star forming region S255IR with ALMA in several spectral windows from ~ 335 GHz to ~ 350 GHz. The main target lines were C$^{34}$S(7-6), CH$_3$CN($19_K-18_K$), CO(3-2) and SiO(8-7), however many other lines of various molecules have been detected, too. We present sample spectra and maps, discuss briefly the source structure and kinematics. A new, never predicted methanol maser line has been discovered.