تقرير
A wind-blown bubble in the Central Molecular Zone cloud G0.253+0.016
| العنوان: | A wind-blown bubble in the Central Molecular Zone cloud G0.253+0.016 |
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| المؤلفون: | Henshaw, J. D., Krumholz, M. R., Butterfield, N. O., Mackey, J., Ginsburg, A., Haworth, T. J., Nogueras-Lara, F., Barnes, A. T., Longmore, S. N., Bally, J., Kruijssen, J. M. D., Mills, E. A. C., Beuther, H., Walker, D. L., Battersby, C., Bulatek, A., Henning, T., Ott, J., Soler, J. D. |
| سنة النشر: | 2021 |
| المجموعة: | Astrophysics |
| مصطلحات موضوعية: | Astrophysics - Astrophysics of Galaxies |
| الوصف: | 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. Comment: 17 pages, 7 figures. Accepted for publication in MNRAS (October 15, 2021) |
| نوع الوثيقة: | Working Paper |
| DOI: | 10.1093/mnras/stab3039 |
| URL الوصول: | http://arxiv.org/abs/2110.11367 |
| رقم الأكسشن: | edsarx.2110.11367 |
| قاعدة البيانات: | arXiv |
| DOI: | 10.1093/mnras/stab3039 |
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