Characteristic scale of star formation – I. Clump formation efficiency on local scales
Abstract
We have used the ratio of column densities derived independently from the 850-μm continuum James Clerk Maxwell Telescope Plane Survey and the ¹³CO/C¹⁸O (J = 3 → 2) Heterodyne Inner Milky Way Plane Survey to produce maps of the dense-gas mass fraction (DGMF) in two slices of the Galactic plane centred at ℓ = 30° and 40°. The observed DGMF is a metric for the instantaneous clump formation efficiency (CFE) in the molecular gas. We split the two fields into velocity components corresponding to the spiral arms that cross them, and a two-dimensional power-spectrum analysis of the spiral-arm DGMF maps reveals a break in slope at the approximate size scale of molecular clouds. We interpret this as the characteristic scale of the amplitude of variations in the CFE and a constraint on the dominant mechanism regulating the CFE and, hence, the star formation efficiency in CO-traced clouds.
Additional Information
© 2020 The Author(s) Published by Oxford University Press on behalf of the Royal Astronomical Society. This article is published and distributed under the terms of the Oxford University Press, Standard Journals Publication Model (https://academic.oup.com/journals/pages/open_access/funder_policies/chorus/standard_publication_model) Accepted 2020 October 10. Received 2020 October 9; in original form 2020 June 30. The authors would like to thank the referee, Michael Burton, for a careful reading of the manuscript, and also Chris Brunt and Ivan Baldry for constructive discussions. DJE is supported by an STFC postdoctoral grant (ST/R000484/1). The JCMT has historically been operated by the Joint Astronomy Centre on behalf of the Science and Technology Facilities Council of the United Kingdom, the National Research Council of Canada, and the Netherlands Organization for Scientific Research. Additional funds for the construction of SCUBA-2 were provided by the Canada Foundation for Innovation. This research has made use of NASA's Astrophysics Data System. The STARLINK software (Currie et al. 2014) is currently supported by the East Asian Observatory. The data used in this paper are available in Eden et al. (2017) and Rigby et al. (2019). DATA AVAILABILITY. The data used for this paper are available from the archives of the JPS (Eden et al. 2017)3 and the CHIMPS (Rigby et al. 2019).4Attached Files
Published - staa3188.pdf
Accepted Version - 2007.00032.pdf
Files
Name | Size | Download all |
---|---|---|
md5:90694bcf5741dad6fd429d7aac32789a
|
5.7 MB | Preview Download |
md5:9ae69c3a065dd59ac30542310090c433
|
2.8 MB | Preview Download |
Additional details
- Eprint ID
- 107502
- Resolver ID
- CaltechAUTHORS:20210114-164620647
- ST/R000484/1
- Science and Technology Facilities Council (STFC)
- Canada Foundation for Innovation
- Created
-
2021-01-15Created from EPrint's datestamp field
- Updated
-
2021-11-16Created from EPrint's last_modified field
- Caltech groups
- Infrared Processing and Analysis Center (IPAC)