Abstract
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.
| Original language | English |
|---|---|
| Pages (from-to) | 107-110 |
| Number of pages | 4 |
| Journal | Proceedings of the International Astronomical Union |
| Volume | 11 |
| DOIs | |
| Publication status | Published - 2016 |
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Keywords
- Molecular clouds
ASJC Scopus subject areas
- Astronomy and Astrophysics
Cite this
Search for the CO-dark mass in the central molecular zone by using the ASTE 10-m telescope. / Tanaka, Kunihiko.
In: Proceedings of the International Astronomical Union, Vol. 11, 2016, p. 107-110.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Search for the CO-dark mass in the central molecular zone by using the ASTE 10-m telescope
AU - Tanaka, Kunihiko
PY - 2016
Y1 - 2016
N2 - 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.
AB - 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.
KW - Molecular clouds
UR - http://www.scopus.com/inward/record.url?scp=85012293807&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=85012293807&partnerID=8YFLogxK
U2 - 10.1017/S1743921316012229
DO - 10.1017/S1743921316012229
M3 - Article
AN - SCOPUS:85012293807
VL - 11
SP - 107
EP - 110
JO - Proceedings of the International Astronomical Union
JF - Proceedings of the International Astronomical Union
SN - 1743-9213
ER -