Stellar population in the vicinity of the H II region G331.03–00.15

CARDENAS SILVINA B.; BLANCO AGUSTINA; GAMEN ROBERTO; CICHOWOLSKI SILVINA

ASTRONOMY AND ASTROPHYSICS

EDP SCIENCES S A

Lugar: Paris; Año: 2022 vol. 666

0004-6361

We present a multi–wavelength study of the H II region G331.03–00.15, aiming to identify the population of massive stars associatedwith it. The distributions of ionised gas and heated dust both exhibit similar spherical forms, while the bordering photo–dissociatingregion follows a very ring–like distribution, indicating abundant surrounding molecular material being photo–dissociated. There isonly one high–mass star catalogued in the region, the WR star 1051–67L. Via an energy analysis of the detected radio continuumemission, we deduced that additional high–mass stars should be interacting with G331.03–00.15. We conducted a search of massivestar candidates by applying a series of colour criteria to a sample of highly–reddened IR point sources projected over the radiocontinuum morphology, with the additional condition that they be located at the same distance assumed for the region. Fourteencandidate sources were selected and classified using low–resolution, NIR spectroscopic data in the H and K bands, obtained withGemini/FLAMINGOS–2. We identified one massive star, and classified it as an O7 V star. Adding the contribution from this newstar to the total ionising radiation available, we concluded it would be possible for the H II region to be powered solely by these twomassive stars. However, we do not rule out the possibility that there could be more early–type stars that remain undetected in thishighly–obscured part of the Galaxy. Additionally, we searched for primary tracers of star–forming activity and identified several ClassI and II candidate YSOs, positioned over the dense clouds and clumps of molecular material found in the area. The presence of severalmaser species located in the densest cloud are also indicative of massive star–formation taking place in the vicinity of G331.03–00.15.