First detection of CS masers around a high-mass young stellar object, W51 e2e

TL;DR

This paper reports the first detection of CS masers around a high-mass young stellar object, revealing a potentially unique phase in high-mass star formation through ALMA and JVLA observations.

Contribution

It presents the first observation of CS masers in a high-mass protostar, expanding the understanding of maser phenomena in star formation.

Findings

CS masers detected in J=1-0 and J=2-1 transitions.

Masers are spatially and spectrally separated, located at the base of the outflow.

These masers may trace a unique phase in high-mass protostar formation.

Abstract

We report the discovery of maser emission in the two lowest rotational transitions of CS toward the high-mass protostar W51 e2e with ALMA and the JVLA. The masers from CS J=1-0 and J=2-1 are neither spatially nor spectrally coincident (they are separated by ~150 AU and ~30 km/s), but both appear to come from the base of the blueshifted outflow from this source. These CS masers join a growing list of rarely-detected maser transitions that may trace a unique phase in the formation of high-mass protostars.