- Title
- 'The Brick' is not a brick: a comprehensive study of the structure and dynamics of the central molecular zone cloud G0.253+0.016
- Creator
- Henshaw, J. D.; Ginsburg, A.; Haworth, T. J.; Longmore, S. N.; Kruijssen, J. M. D.; Mills, E. A. C.; Sokolov, V.; Walker, D. L.; Barnes, A. T.; Contreras, Y.; Bally, J.; Battersby, C.; Beuther, H.; Butterfield, N.; Dale, J. E.; Henning, T.; Jackson, J. M.; Kauffmann, J.; Pillai, T.; Ragan, S.
- Relation
- Monthly Notices of the Royal Astronomical Society Vol. 485, Issue 2, p. 2457-2485
- Publisher Link
- http://dx.doi.org/10.1093/mnras/stz471
- Publisher
- Oxford University Press
- Resource Type
- journal article
- Date
- 2019
- Description
- In this paper we provide a comprehensive description of the internal dynamics of G0.253+0.016 (a.k.a. ‘the Brick’); one of the most massive and dense molecular clouds in the Galaxy to lack signatures of widespread star formation. As a potential host to a future generation of high-mass stars, understanding largely quiescent molecular clouds like G0.253+0.016 is of critical importance. In this paper, we reanalyse Atacama Large Millimeter Array cycle 0 HNCO J = 4(0, 4) − 3(0, 3) data at 3 mm, using two new pieces of software that we make available to the community. First, SCOUSEPY, a Python implementation of the spectral line fitting algorithm SCOUSE. Secondly, ACORNS (Agglomerative Clustering for ORganising Nested Structures), a hierarchical n-dimensional clustering algorithm designed for use with discrete spectroscopic data. Together, these tools provide an unbiased measurement of the line-of-sight velocity dispersion in this cloud, σvlos,1D=4.4±2.1 km s−1, which is somewhat larger than predicted by velocity dispersion-size relations for the central molecular zone (CMZ). The dispersion of centroid velocities in the plane of the sky are comparable, yielding σvlos,1D/σvpos,1D∼1.2±0.3. This isotropy may indicate that the line-of-sight extent of the cloud is approximately equivalent to that in the plane of the sky. Combining our kinematic decomposition with radiative transfer modelling, we conclude that G0.253+0.016 is not a single, coherent, and centrally condensed molecular cloud; ‘the Brick’ is not a brick. Instead, G0.253+0.016 is a dynamically complex and hierarchically structured molecular cloud whose morphology is consistent with the influence of the orbital dynamics and shear in the CMZ.
- Subject
- turbulence; stars: formation; ISM: clouds; ISM: kinematics and dynamics; ISM: structure; galaxy: centre
- Identifier
- http://hdl.handle.net/1959.13/1458870
- Identifier
- uon:45526
- Identifier
- ISSN:0035-8711
- Language
- eng
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