Studying star-forming processes at core and clump scales: the case of the young stellar object G29.862-0.0044

FARIÑA, C.; RUBIO, M.; AREAL, M. B.; ORTEGA, M. E.; PARON S.; CELIS PEÑA, M.

ASTRONOMY AND ASTROPHYSICS

EDP SCIENCES S A

Año: 2020

0004-6361

Aims. To advance in our knowledge about star formation, besides the statistical studies and large surveys of young stellar objects(YSOs), it is important to do detailed studies towards particular objects. Given that massive molecular clumps fragment into coreswhere star formation takes place, this kind of studies should be done at different spatial scales.Methods. Using near-IR data obtained with NIRI at the Gemini-North telescope, data of the complex molecular species CH3OCHOand CH3CN obtained from the Atacama Large Millimeter Array (ALMA) database, observations of HCN, HNC, HCO+, and C2Hcarried out with the Atacama Submillimeter Telescope Experiment (ASTE), and CO data from public surveys observed with theJames Clerck Maxwell Telescope (JCMT), we perform a deep study of the YSO G29.862−0.0044 (YSO-G29) at core and clumpspatial scales.Results. The near-IR emission shows that YSO-G29 is composed by two nebulosities separated by a dark lane, suggesting a scenarioconsistent with a typical disk-jets system, but in this case, highly asymmetric. The northern nebulosity is open, diffuse and it is dividedinto two branches, while the southern one is smaller and sharper. They are likely produced by the scattered light in cavities carvedout by jets or winds on an infalling envelope of material, which also present line emission of H2 S(1) 1?0 and 2?1, and [FeII]. Thepresence of the complex molecular species observed with ALMA confirms that we are mapping a hot molecular core. The CH3CNemission concentrates at the position of the dark lane and it appears slightly elongated from southwest to northeast in agreementwith the inclination of the system as observed at near-IR. The morphology of the CH3OCHO emission is more complex and extendsalong some filaments and concentrates in knots and clumps, mainly southwards the dark-lane, suggesting that the southern jet isencountering a dense region. The northern jet can flow more freely, generating the more extended features as seen at near-IR. Thisis in agreement with the red-shifted molecular outflow traced by the 12CO J=3?2 line extending towards the northwest and the lackof a blue-shifted outflow. This configuration can be explained by considering that G29-YSO is located at the furthest edge of themolecular clump along the line of sight, which is consistent with the position of the source in the cloud mapped in the C18O J=3?2line. The detection of HCN, HNC, HCO+, and C2H allowed us to characterize the dense gas at clump scales, yielding results that arein agreement with the presence of a high-mass protostellar object.