Henshaw, JD, Krumholz, MR, Butterfield, NO, Mackey, J, Ginsburg, A, Haworth, TJ, Nogueras-Lara, F, Barnes, AT, Longmore, SN, Bally, J, Kruijssen, JMD, Mills, EAC, Beuther, H, Walker, DL, Battersby, C, Bulatek, A, Henning, T, Ott, J and Soler, JD (2021) A wind-blown bubble in the Central Molecular Zone cloud G0.253+0.016. Monthly Notices of the Royal Astronomical Society, 509 (4). pp. 4758-4774. ISSN 0035-8711

Preview

Text stab3039.pdf - Published Version Download (2MB) | Preview

Abstract

G0.253+0.016, commonly referred to as "the Brick" and located within the Central Molecular Zone, is one of the densest ($\approx10^{3-4}$ cm$^{-3}$) molecular clouds in the Galaxy to lack signatures of widespread star formation. We set out to constrain the origins of an arc-shaped molecular line emission feature located within the cloud. We determine that the arc, centred on $\{l_{0},b_{0}\}=\{0.248^{\circ}, 0.18^{\circ}\}$, has a radius of $1.3$ pc and kinematics indicative of the presence of a shell expanding at $5.2^{+2.7}_{-1.9}$ km s$^{-1}$. Extended radio continuum emission fills the arc cavity and recombination line emission peaks at a similar velocity to the arc, implying that the molecular and ionised gas are physically related. The inferred Lyman continuum photon rate is $N_{\rm LyC}=10^{46.0}-10^{47.9}$ photons s$^{-1}$, consistent with a star of spectral type B1-O8.5, corresponding to a mass of $\approx12-20$ M$_{\odot}$. We explore two scenarios for the origin of the arc: i) a partial shell swept up by the wind of an interloper high-mass star; ii) a partial shell swept up by stellar feedback resulting from in-situ star formation. We favour the latter scenario, finding reasonable (factor of a few) agreement between its morphology, dynamics, and energetics and those predicted for an expanding bubble driven by the wind from a high-mass star. The immediate implication is that G0.253+0.016 may not be as quiescent as is commonly accepted. We speculate that the cloud may have produced a $\lesssim10^{3}$ M$_{\odot}$ star cluster $\gtrsim0.4$ Myr ago, and demonstrate that the high-extinction and stellar crowding observed towards G0.253+0.016 may help to obscure such a star cluster from detection.

Item Type:	Article
Additional Information:	This article has been accepted for publication in Monthly Notices of the Royal Astronomical Society ©:2021 The Author(s) Monthly Notices of the Royal Astronomical Society. Published by Oxford University Press on behalf of the Royal Astronomical Society. All rights reserved.
Uncontrolled Keywords:	astro-ph.GA; astro-ph.GA
Subjects:	Q Science > QB Astronomy Q Science > QC Physics
Divisions:	Astrophysics Research Institute
Publisher:	Oxford University Press
Related URLs:	http://arxiv.org/abs/2110.11367v1
Date Deposited:	08 Nov 2021 10:13
Last Modified:	21 Mar 2023 13:15
DOI or ID number:	10.1093/mnras/stab3039
URI:	https://researchonline.ljmu.ac.uk/id/eprint/15751

View Item