INTERSTELLAR MEDIUM PROCESSING IN THE INNER 20 pc IN GALACTIC CENTER

被引:34
作者
Liu, Hauyu Baobab [1 ]
Ho, Paul T. P. [1 ,2 ]
Wright, Melvyn C. H. [3 ]
Su, Yu-Nung [1 ]
Hsieh, Pei-Ying [1 ,4 ]
Sun, Ai-Lei [5 ]
Kim, Sungsoo S. [6 ]
Minh, Young Chol [7 ]
机构
[1] Acad Sinica, Inst Astron & Astrophys, Taipei 106, Taiwan
[2] Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA
[3] Univ Calif Berkeley, Radio Astron Lab, Berkeley, CA 94720 USA
[4] Natl Cent Univ, Grad Inst Astron, Jhongli 32001, Taoyuan County, Taiwan
[5] Princeton Univ, Dept Astrophys Sci, Princeton, NJ 08544 USA
[6] Kyung Hee Univ, Dept Astron & Space Sci, Yongin 446701, Kyungki Do, South Korea
[7] Korea Astron & Space Sci Inst KASI, Taejon 305348, South Korea
基金
新加坡国家研究基金会;
关键词
Galaxy: center; Galaxy: kinematics and dynamics; Galaxy: structure; ISM: clouds; stars: formation; techniques: interferometric; MASSIVE STAR-FORMATION; LARGE ARRAY OBSERVATIONS; SUPERMASSIVE BLACK-HOLE; SAGITTARIUS A-ASTERISK; I METHANOL MASERS; CIRCUMNUCLEAR DISK; MOLECULAR CLOUDS; SGR-A; FORMING REGIONS; STELLAR ORBITS;
D O I
10.1088/0004-637X/770/1/44
中图分类号
P1 [天文学];
学科分类号
0704 ;
摘要
We present the Submillimeter Array 157 pointing mosaic in 0.86 mm dust continuum emission with 5 ''.1 x 4 ''.2 angular resolution, and the National Radio Astronomy Observatory Green Bank 100 m Telescope (GBT) observations of the CS/(CS)-S-34/(CS)-C-13 1-0 and SiO 1-0 emission with <= 20 '' x 18 '' angular resolution. The dust continuum image marginally resolves at least several tens of 10-10(2) M-circle dot dense clumps in the 5' field including the circumnuclear disk (CND) and the exterior gas streamers. There is very good agreement between the high resolution dust continuum map of the CND and all previous molecular line observations. As the dust emission is the most reliable optically thin tracer of the mass, free from most chemical and excitation effects, we demonstrate the reality of the abundant localized structures within the CND, and their connection to external gas structures. From the spectral line data, the velocity dispersions of the dense clumps and their parent molecular clouds are similar to 10-20 times higher than their virial velocity dispersions. This supports the idea that the CND and its immediate environment may not be stationary or stable structures. Some of the dense gas clumps are associated with 22 GHz water masers and 36.2 GHz and 44.1 GHz CH3OH masers. However, we do not find clumps that are bound by the gravity of the enclosed molecular gas. Hence, the CH3OH or H2O maser emission may be due to strong (proto) stellar feedback, which may be dispersing some of the gas clumps.
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页数:15
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