Universität zu Köln

Barnes, A. T., Henshaw, J. D., Fontani, F., Pineda, J. E., Cosentino, G., Tan, J. C., Caselli, P., Jimenez-Serra, I, Law, C. Y., Avison, A., Bigiel, F., Feng, S., Kong, S., Longmore, S. N., Moser, L., Parker, R. J., Sanchez-Monge, A. and Wang, K. (2021). ALMA-IRDC: dense gas mass distribution from cloud to core scales. Mon. Not. Roy. Astron. Soc., 503 (3). S. 4601 - 4627. OXFORD: OXFORD UNIV PRESS. ISSN 1365-2966

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Abstract

Infrared dark clouds (IRDCs) are potential hosts of the elusive early phases of high mass star formation (HMSF). Here, we conduct an in-depth analysis of the fragmentation properties of a sample of 10 IRDCs, which have been highlighted as some of the best candidates to study HMSF within the Milky Way. To do so, we have obtained a set of large mosaics covering these IRDCs with Atacama Large Millimeter/submillimeter Array (ALMA) at Band 3 (or 3 mm). These observations have a high angular resolution (similar to 3 arcsec; similar to 0.05 pc), and high continuum and spectral line sensitivity (similar to 0.15 mJy beam(-1) and similar to 0.2 K per 0.1 km s(-1) channel at the N2H+ (1 - 0) transition). From the dust continuum emission, we identify 96 cores ranging from low to high mass (M = 3.4-50.9M(circle dot)) that are gravitationally bound (alpha(vir) = 0.3-1.3) and which would require magnetic field strengths of B = 0.3-1.0 mG to be in virial equilibrium. We combine these results with a homogenized catalogue of literature cores to recover the hierarchical structure within these clouds over four orders of magnitude in spatial scale (0.01-10 pc). Using supplementary observations at an even higher angular resolution, we find that the smallest fragments (<0.02 pc) within this hierarchy do not currently have the mass and/or the density required to form high-mass stars. None the less, the new ALMA observations presented in this paper have facilitated the identification of 19 (6 quiescent and 13 star-forming) cores that retain >16M(circle dot) without further fragmentation. These high-mass cores contain trans-sonic non-thermal motions, are kinematically sub-virial, and require moderate magnetic field strengths for support against collapse. The identification of these potential sites of HMSF represents a key step in allowing us to test the predictions from high-mass star and cluster formation theories.

Item Type:	Journal Article
Creators:	Creators Email ORCID ORCID Put Code Barnes, A. T. UNSPECIFIED UNSPECIFIED UNSPECIFIED Henshaw, J. D. UNSPECIFIED UNSPECIFIED UNSPECIFIED Fontani, F. UNSPECIFIED UNSPECIFIED UNSPECIFIED Pineda, J. E. UNSPECIFIED UNSPECIFIED UNSPECIFIED Cosentino, G. UNSPECIFIED UNSPECIFIED UNSPECIFIED Tan, J. C. UNSPECIFIED UNSPECIFIED UNSPECIFIED Caselli, P. UNSPECIFIED UNSPECIFIED UNSPECIFIED Jimenez-Serra, I UNSPECIFIED UNSPECIFIED UNSPECIFIED Law, C. Y. UNSPECIFIED UNSPECIFIED UNSPECIFIED Avison, A. UNSPECIFIED UNSPECIFIED UNSPECIFIED Bigiel, F. UNSPECIFIED UNSPECIFIED UNSPECIFIED Feng, S. UNSPECIFIED UNSPECIFIED UNSPECIFIED Kong, S. UNSPECIFIED UNSPECIFIED UNSPECIFIED Longmore, S. N. UNSPECIFIED UNSPECIFIED UNSPECIFIED Moser, L. UNSPECIFIED UNSPECIFIED UNSPECIFIED Parker, R. J. UNSPECIFIED UNSPECIFIED UNSPECIFIED Sanchez-Monge, A. UNSPECIFIED UNSPECIFIED UNSPECIFIED Wang, K. UNSPECIFIED UNSPECIFIED UNSPECIFIED
URN:	urn:nbn:de:hbz:38-604442
DOI:	10.1093/mnras/stab803
Journal or Publication Title:	Mon. Not. Roy. Astron. Soc.
Volume:	503
Number:	3
Page Range:	S. 4601 - 4627
Date:	2021
Publisher:	OXFORD UNIV PRESS
Place of Publication:	OXFORD
ISSN:	1365-2966
Language:	English
Faculty:	Unspecified
Divisions:	Unspecified
Subjects:	no entry
Uncontrolled Keywords:	Keywords Language INFRARED DARK CLOUD; LARGE ARRAY OBSERVATIONS; STAR-FORMATION; MAGNETIC-FIELDS; PHYSICAL-PROPERTIES; SIZE RELATION; VELOCITY-COHERENT; MOLECULAR CLOUD; GALACTIC PLANE; COLUMN DENSITY Multiple languages Astronomy & Astrophysics Multiple languages
URI:	http://kups.ub.uni-koeln.de/id/eprint/60444