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Molecular Clouds with CO-dark Envelopes in the Extended Ultraviolet (XUV) Disk of M83

Published online by Cambridge University Press:  09 June 2023

Jin Koda*
Affiliation:
Department of Physics and Astronomy, Stony Brook University, Stony Brook, NY 11794-3800

Abstract

We report a CO(3-2) detection of 23 molecular clouds in the extended ultraviolet (XUV) disk of the spiral galaxy M83 with ALMA. The observed 1 kpc2 region is at about 1.24R25 from the disk center, where CO(2-1) was previously not detected. The detection and non-detection, as well as the level of star formation (SF) activity in the region, can be explained consistently if the clouds have the mass distribution common among Galactic clouds, such as Orion A – with star-forming dense clumps embedded in thick layers of bulk molecular gas, but in a low-metallicity regime where their outer layers are CO-deficient and CO-dark. The cloud masses, estimated from CO(3-2), range from 8.2×102 to 2.3×104M. The most massive clouds appear similar to Orion A in SF activity as well as in gas mass. The common cloud mass structure also justifies the use of high-J CO transitions to trace the total gas mass of clouds, or galaxies, even in the high-z universe. This study is the first demonstration that CO(3-2) is an efficient tracer of molecular clouds even in low-metallicity environments. This study is published in the Astronomical Journal, entitled “First Detection of the Molecular Cloud Population in the Extended Ultraviolet (XUV) Disk of M83" by J. Koda, L. Watson, F. Combes, M. Rubio, S. Boissier, M. Yagi, D. Thilker, A. M Lee, Y. Komiyama, K. Morokuma-Matsui, and C. Verdugo.

Type
Contributed Paper
Copyright
© The Author(s), 2023. Published by Cambridge University Press on behalf of International Astronomical Union

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References

Gil de Paz, A., Madore, B. F., Boissier, S., et al. 2005, ApJL, 627, L29 10.1086/432054CrossRefGoogle Scholar
Thilker, D. A., Bianchi, L., Meurer, G., et al. 2007, ApJS, 173, 538 Google Scholar
Watson, L. C., & Koda, J. 2017, in Outskirts of Galaxies, ed. Knapen, J. H., Lee, J. C., & Gil de Paz, A., Vol. 434, 175 10.1007/978-3-319-56570-5_6CrossRefGoogle Scholar
Braine, J., & Herpin, F. 2004, Nature, 432, 369 10.1038/nature03054CrossRefGoogle Scholar
Braine, J., Ferguson, A. M. N., Bertoldi, F., & Wilson, C. D. 2007, ApJL, 669, L73 10.1086/524135CrossRefGoogle Scholar
Braine, J., Gratier, P., Kramer, C., et al. 2010, A&A, 520, A107 10.1051/0004-6361/201014166CrossRefGoogle Scholar
Dessauges-Zavadsky, M., Verdugo, C., Combes, F., & Pfenniger, D. 2014, A&A, 566, A147 10.1051/0004-6361/201323330CrossRefGoogle Scholar
Braine, J., Gratier, P., Contreras, Y., Schuster, K. F., & Brouillet, N. 2012, A&A, 548, A52 10.1051/0004-6361/201220093CrossRefGoogle Scholar
Bicalho, I. C., Combes, F., Rubio, M., Verdugo, C., & Salome, P. 2019, A&A, 623, A66 10.1051/0004-6361/201732352CrossRefGoogle Scholar
Williams, J. P., de Geus, E. J., & Blitz, L. 1994, ApJ, 428, 693 10.1086/174279CrossRefGoogle Scholar
Scoville, N. Z., Polletta, M., Ewald, S., et al. 2001, AJ, 122, 3017 10.1086/323445CrossRefGoogle Scholar
Sakamoto, S., Hayashi, M., Hasegawa, T., Handa, T., & Oka, T. 1994, ApJ, 425, 641 10.1086/174011CrossRefGoogle Scholar
Nakamura, F., Ishii, S., Dobashi, K., et al. 2019, PASJ, 71, S3 Google Scholar
Kong, S., Arce, H. G., Feddersen, J. R., et al. 2018, ApJS, 236, 25 Google Scholar
Ikeda, M., Maezawa, H., Ito, T., et al. 1999, ApJL, 527, L59 10.1086/312395CrossRefGoogle Scholar
Masui, S., Yamasaki, Y., Ogawa, H., et al. 2021, PASJ, 73, 1100 Google Scholar
Nakamura, T., Kodaira, S., Ishii, K., Inatani, J., & Ohishi, M. 1984, PASJ, 36, 123 Google Scholar
Enoch, M. L., Evans, II, N. J., Sargent, A. I., et al. 2008, ApJ, 684, 124010.1086/589963CrossRefGoogle Scholar
Watanabe, Y., Nishimura, Y., Harada, N., et al. 2017, ApJ, 845, 116 10.3847/1538-4357/aa7eceCrossRefGoogle Scholar
Barnes, A. T., Kauffmann, J., Bigiel, F., et al. 2020, MNRAS, 497, 1972 10.1093/mnras/staa1814CrossRefGoogle Scholar
Maloney, P., & Black, J. H. 1988, ApJ, 325, 389 10.1086/166011CrossRefGoogle Scholar
van Dishoeck, E. F., & Black, J. H. 1988, ApJ, 334, 771 10.1086/166877CrossRefGoogle Scholar
Wolfire, M. G., Hollenbach, D., & McKee, C. F. 2010, ApJ, 716, 1191 10.1088/0004-637X/716/2/1191CrossRefGoogle Scholar
Wilson, C. D., Warren, B. E., Israel, F. P., et al. 2009, ApJ, 693, 1736 10.1088/0004-637X/693/2/1736CrossRefGoogle Scholar
Gil de Paz, A., Boissier, S., Madore, B. F., et al. 2007b, ApJS, 173, 18510.1086/516636CrossRefGoogle Scholar