High-mass star formation in the nearby region G352.630-1.067. I. parallax

Abstract

Young or forming high-mass stars that are nearby and not within a cluster environment have the potential to provide fundamental insights into star formation. In this paper we report such a candidate (G352.630-1.067), for which we have measured the distance through very long baseline interferometry parallax observations of the associated 6.7 GHz class II methanol maser. We determine the distance to the source to be 0.69 -0.08 +0.10 kpc, which makes it the second nearest highmass star formation region (HMSFR) known, with only the Orion Nebula being closer. This may place this source, not within a Galactic spiral arm, but in the region between the Local and Sagittarius arms, indicating that molecular clouds in interarm regions may also generate high-mass stars. Kinematic association between this source and the Sagittarius Arm suggests that it may be located in a spur extending outward from this arm. Comparison with the known, nearby HMSFRs (distances less than 1 kpc), reveal that G352.630-1.067 is in a more isolated environment than others, hence providing an excellent candidate for investigations of the processes that form individual high-mass stars. We find a good spatial correlation between the 6.7 GHz methanol maser and high angular resolution images of the infrared outflow, suggesting that the class II methanol masers are closely associated with a jet/outflow in this source. © 2019 The American Astronomical Society.