In:
The Astrophysical Journal, American Astronomical Society, Vol. 955, No. 2 ( 2023-10-01), p. 154-
Abstract:
We have used the IRAM 30 m telescope to map some targets with HCO + (1–0) and H 13 CO + (1–0) lines in order to search for evidence of gas infall in clumps. In this paper, we report the mapping results for 13 targets. All of these targets show HCO + emissions, while H 13 CO + emissions are observed in 10 of them. The HCO + integrated intensity maps of 10 targets show clear clumpy structures, and nine targets show clumpy structures in the H 13 CO + maps. Using the RADEX radiative transfer code, we estimate the column density of H 13 CO + , and we determine the abundance ratio [H 13 CO + ]/[H 2 ] to be approximately 10 −12 –10 −10 . Based on the asymmetry of the HCO + line profiles, we identify 11 targets that show blue profiles, while six clumps have evidence of global infall. We use the RATRAN and two-layer models to fit the HCO + line profiles of these infall sources, and analyze their spatial distribution of the infall velocity. The average infall velocities estimated by these two models are 0.24–1.85 km s −1 and 0.28–1.45 km s −1 , respectively. The mass infall rate ranges from approximately 10 −5 to 10 −2 M ⊙ yr −1 , which suggests that intermediate- or high-mass stars may be forming in the target regions.
Type of Medium:
Online Resource
ISSN:
0004-637X
,
1538-4357
DOI:
10.3847/1538-4357/aced09
Language:
Unknown
Publisher:
American Astronomical Society
Publication Date:
2023
detail.hit.zdb_id:
2207648-7
detail.hit.zdb_id:
1473835-1
SSG:
16,12
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