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arXiv · 1706.09944

ALMA Detects CO(3-2) within a Super Star Cluster in NGC5253

J. L. Turner·S. M. Consiglio·S. C. Beck·W. M. Goss·P. T. P. Ho·D. S. Meier·S. Silich·J. -H. Zhao
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Abstract

We present observations of CO(3-2) and $^{13}$CO(3-2) emission near the supernebula in the dwarf galaxy NGC 5253, which contains one of the best examples of a potential globular cluster in formation. The 0.3" resolution images reveal an unusual molecular cloud, "Cloud D1", coincident with the radio-infrared supernebula. The ~6-pc diameter cloud has a linewidth, $Δ$ v = 21.7 km/s, that reflects only the gravitational potential of the star cluster residing within it. The corresponding virial mass is 2.5 x 10$^5$ M$_\odot$. The cluster appears to have a top-heavy initial mass function, with $M_{low}$~1-2 M$_\odot$. Cloud D1 is optically thin in CO(3-2) probably because the gas is hot. Molecular gas mass is very uncertain but constitutes < 35% of the dynamical mass within the cloud boundaries. In spite of the presence of an estimated ~1500-2000 O stars within the small cloud, the CO appears relatively undisturbed. We propose that Cloud D1 consists of molecular clumps or cores, possibly star-forming, orbiting with more evolved stars in the core of the giant cluster.

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J. L. Turner, S. M. Consiglio, S. C. Beck, W. M. Goss, P. T. P. Ho, D. S. Meier, S. Silich, J. -H. Zhao. 2020-05-14. ALMA Detects CO(3-2) within a Super Star Cluster in NGC5253. https://doi.org/10.3847/1538-4357%2Faa8669

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