ATOMS: ALMA three-millimeter observations of massive star-forming regions - III. Catalogues of candidate hot molecular cores and hyper/ultra compact H II regions
Abstract
We have identified 453 compact dense cores in 3 mm continuum emission maps in the ALMA Three-millimetre Observations of Massive Star-forming regions survey, and compiled three catalogues of high-mass star-forming cores. One catalogue, referred to as hyper/ultra compact (H/UC)-H II catalogue, includes 89 cores that enshroud H/UC H II regions as characterized by associated compact H40α emission. A second catalogue, referred to as pure s-cHMC, includes 32 candidate hot molecular cores (HMCs) showing rich spectra (N ≥ 20 lines) of complex organic molecules (COMs) and not associated with H/UC-H II regions. The third catalogue, referred to as pure w-cHMC, includes 58 candidate HMCs with relatively low levels of COM richness and not associated with H/UC-H II regions. These three catalogues of dense cores provide an important foundation for future studies of the early stages of high-mass star formation across the Milky Way. We also find that nearly half of H/UC-H II cores are candidate HMCs. From the number counts of COM-containing and H/UC-H II cores, we suggest that the duration of high-mass protostellar cores showing chemically rich features is at least comparable to the lifetime of H/UC-H II regions. For cores in the H/UC-H II catalogue, the width of the H40α line increases as the core size decreases, suggesting that the non-thermal dynamical and/or pressure line-broadening mechanisms dominate on the smaller scales of the H/UC-H II cores.
- Publication:
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Monthly Notices of the Royal Astronomical Society
- Pub Date:
- August 2021
- DOI:
- arXiv:
- arXiv:2105.03554
- Bibcode:
- 2021MNRAS.505.2801L
- Keywords:
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- stars: formation;
- stars: kinematics and dynamics;
- ISM: clouds;
- H II regions;
- Astrophysics - Astrophysics of Galaxies;
- Astrophysics - Solar and Stellar Astrophysics
- E-Print:
- 17 pages, five tables, and 11 figures. Accepted for publication at MNRAS