Hostname: page-component-cd9895bd7-dk4vv Total loading time: 0 Render date: 2024-12-25T04:45:26.413Z Has data issue: false hasContentIssue false
  • English
  • Français

Search for the CO-dark Mass in the Central Molecular Zone by using the ASTE 10-m Telescope

Published online by Cambridge University Press:  09 February 2017

Kunihiko Tanaka
Kunihiko Tanaka*
Affiliation:
Institute of Science and Technology, Keio University, 3-14-1 Hiyoshi, Kohoku, Yokohama, Japan email: [email protected]
Rights & Permissions [Opens in a new window]

Abstract

Core share and HTML view are not available for this content. However, as you have access to this content, a full PDF is available via the ‘Save PDF’ action button.

Atomic carbon (C0) is one of the most abundant carbon-bearing species in the interstellar molecular gas, and its submillimeter lines are good tracers of low-density molecular clouds which are often dark in CO rotational lines. We present a new map of the central 150 pc region of the Milky Way in the 500 GHz [CI] line, which has been recently obtained with the ASTE 10-m telescope. The [CI] emission is brightest toward the central 5-pc region, where massive GMCs are absent. This [CI]-bright region is approximately centered toward Sgr A*, covering the entire circum-nuclear ring (CND) and the western part of the 50-km/s cloud. The C0/CO abundance ratio is 0.5–2 there, and the highest ratio is observed toward the CND but just outside of the 2-pc ring of dense gas. This discovery may suggest that the CO-dark component occupies a significant fraction of the molecular gas in the circumnuclear region.

Keywords

Molecular clouds
Type
Contributed Papers
Information
Proceedings of the International Astronomical Union , Volume 11 , Symposium S322: The Multi-Messenger Astrophysics of the Galactic Centre , July 2016 , pp. 107 - 110
Copyright
Copyright © International Astronomical Union 2017 

References

Fixsen, D. J., Bennett, C. L., & Mather, J. C. 1999, ApJ, 526, 207 CrossRefGoogle Scholar
Ginsburg, A., Henkel, C., Ao, Y., et al. 2016, A&A, 50, 1 Google Scholar
Harada, N., Riquelme, D., Viti, S., Jiméz-Serra, I., Requena-Torres, M. A., Menten, K. M., Martín, S., Aladro, R., Martín-Pintado, J.,& Hochgürtel, S. 2015, A&A, 584, 102 Google Scholar
Israel, F. P. & Baas, F. 2002, A&A, 90, 82 Google Scholar
Requena-Torres, M. A., Güsten, R., Weiß, A., et al. 2012, A&A, 542, L21 Google Scholar
Tanaka, K., Oka, T., Matsumura, S., Nagai, M., & Kamegai, K. 2011, ApJL, 743, L39 Google Scholar
Rosenberg, M. J. F., van der Werf, P. P., Aalto, S., et al. 2015, ApJ, 801, 72 Google Scholar
Shimajiri, Y., Sakai, T., Tsukagoshi, T., et al. 2013, ApJL, 774, L20 CrossRefGoogle Scholar