期刊
ASTROPHYSICAL JOURNAL
卷 696, 期 1, 页码 176-181出版社
IOP PUBLISHING LTD
DOI: 10.1088/0004-637X/696/1/176
关键词
galaxies: individual (NGC5128, Cen A); galaxies: ISM; ISM: molecules; radio lines: galaxies
资金
- Smithsonian Institution
- Academia Sinica
We have investigated the presence of dense gas toward the radio source Cen A by looking at the absorption of the HCO+ and HCN (3-2) lines in front of the bright continuum source with the Submillimeter Array. We detect narrow HCO+ (3-2) absorption, and tentatively HCN (3-2), close to the systemic velocity. For both molecules, the J = 3 - 2 absorption is much weaker than for the J = 1 - 0 line. From simple excitation analysis, we conclude that the gas density is of the order of a few 10(4) cm(-3) for a column density N(HCO+)/Delta V of 3 x 10(12) cm(-2) km(-1) s and a kinetic temperature of 10 K. In particular, we find no evidence for molecular gas density higher than a few 10(4) cm(-3) on the line of sight to the continuum source. We discuss the implications of our finding on the nature of the molecular gas responsible for the absorption toward Cen A.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据