Infall and outflow towards high-mass starless clump candidates

Journal
Date Issued
2023
Author(s)
Pillai, T. G. S.
•
Urquhart, J. S.
•
•
Zhang, Q.
•
•
Colombo, D.
•
Wang, K.
•
Gomez, L.
•
Wyrowski, F.
DOI
Abstract
The evolutionary sequence for high-mass star formation starts with massive starless clumps that go on to form protostellar, young stellar objects and then compact H II regions. While there are many examples of the three later stages, the very early stages have proved to be elusive. We follow-up a sample of 110 mid-infrared dark clumps selected from the ATLASGAL catalogue with the IRAM telescope in an effort to identify a robust sample of massive starless clumps. We have used the HCO+ and HNC (1-0) transitions to identify clumps associated with infall motion and the SiO (2-1) transition to identity outflow candidates. We have found blue asymmetric line profile in 65 per cent of the sample, and have measured the infall velocities and mass infall rates (0.6-36 × 10-3 M⊙ yr-1) for 33 of these clumps. We find a trend for the mass infall rate decreasing with an increase of bolometric luminosity to clump mass, i.e. star formation within the clumps evolves. Using the SiO 2-1 line, we have identified good outflow candidates. Combining the infall and outflow tracers reveals that 67 per cent of quiescent clumps are already undergoing gravitational collapse or are associated with star formation; these clumps provide us with our best opportunity to determine the initial conditions and study the earliest stages of massive star formation. Finally, we provide an overview of a systematic high-resolution ALMA study of quiescent clumps selected that allows us to develop a detailed understanding of earliest stages and their subsequent evolution.
Volume
522
Issue
3
Start page
3357
Uri
Url
Issn Identifier
0035-8711
Ads BibCode
2023MNRAS.522.3357P
Rights
open.access
File(s)
Loading...
Thumbnail Image
Name

stad1073.pdf

Description
Pdf editoriale
Size

1.1 MB

Format

Adobe PDF

Checksum (MD5)

6641d791d0cec8278f3fc0f71277ddbf

Loading...
Thumbnail Image
Name

2305.04256v1.pdf

Size

481.29 KB

Format

Adobe PDF

Checksum (MD5)

1782c73994354148e3dc140890dd5180