The kinematics of molecular clumps surrounding hot cores in G29.96-0.02 and G31.41+0.31

Abstract

We present high angular resolution interferometric observations of the 3 and 1.3mm continuum emission, and HCO+(1-0) and SiO(2-1)v=0 lines, obtained with the Owens Valley Radio Observatory millimeter-wave array, toward two hot cores (HCs) associated with two well known ultracompact (UC) HII regions: G29.96-0.02 and G31.41+0.31. These HCs are believed to host young forming massive stars which have been suggested to be surrounded by massive rotating accretion disks. The aim of these new observations is to study the structure and kinematics of the molecular clumps surrounding the HCs and nearby UCHII regions at moderately high angular resolution. Our observations reveal that the clumps within which the HCs and UCHII regions are embedded have a complex kinematical structure. The total mass of the clumps is estimated to be in the range 1000-3000 Msun, consistent with previous findings. Our observations also show compelling evidence that the clump in G29.96-0.02 is contracting onto the HC position, suggesting that the accretion process onto the massive young stellar object embedded in the HC is still ongoing. In these objects the kinematical structure that we observe is also compatible with the presence of a massive rotating disk within the HC, even though we cannot prove this suggestion with our data. The case of G31.41+0.31 is more complicated, and our data, although consistent with the presence of an inner disk and an infalling envelope around it, do not have the required spatial resolution to resolve the different structures.

13 pages, 15 figs, A&A in press

Cited by in corpus (23)

• The pre-launch Planck Sky Model: a model of sky emission at submillimetre to centimetre wavelengths
• A detailed study of the rotating toroids in G31.41+0.31 and G24.78+0.08
• Rotating toroids in G10.62-0.38, G19.61-0.23, and G29.96-0.02
• Dust and gas emission in the prototypical hot core G29.96-0.02 at sub-arcsecond resolution
• The structure of molecular clumps around high-mass young stellar objects
• Collapsing Hot Molecular Cores: A Model for the Dust Spectrum and Ammonia Line Emission of the G31.41+0.31 Hot Core
• Candidate Rotating Toroids around High-Mass (Proto)Stars
• High-velocity gas toward hot molecular cores: evidence for collimated outflows from embedded sources
• Detection of reactive ions in the ultracompact HII regions Mon R2 and G29.96-0.02
• Mid-Infrared Detection of a Hot Molecular Core in G29.96-0.02
• A high resolution study of complex organic molecules in hot cores
• A Hi-GAL study of the high-mass star-forming region G29.96-0.02
• A Search for H2CO 6cm Emission toward Young Stellar Objects III: VLA Observations
• FOREST Unbiased Galactic plane Imaging survey with the Nobeyama 45 m telescope (FUGIN). VI. Dense gas and mini-starbursts in the W43 giant molecular cloud complex
• Observations and Modeling of the 2-25um Emission From High Mass Protostellar Object Candidates
• Looking for outflow and infall signatures in high mass star forming regions
• New signposts of massive star formation in the S235A-B region
• A VLT spectroscopic study of the ultracompact HII region G29.96-0.02
• The hot core-ultracompact HII connection in G10.47+0.03
• New detections of (sub)millimeter hydrogen radio recombination lines towards high-mass star-forming clumps
• Mid- and high-J CO observations towards UCHIIs
• Radiative transfer modeling of the observed line profiles in G31.41+0.31
• The role of neutral hydrogen in setting the abundances of molecular species in the Milky Way's diffuse interstellar medium. II. Comparison between observations and theoretical models