arXiv Analytics

Sign in

arXiv:0902.0122 [astro-ph.CO]AbstractReferencesReviewsResources

HCO+ and HCN J=3-2 absorption toward the center of Centaurus A

Sebastien Muller, Dinh-V-Trung

Published 2009-02-01Version 1

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 on the order of a few 10^4 cm^-3 for a column density N(HCO+)/dV of 3x10^12 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.

Comments: Accepted for publication in ApJ
Journal: Astrophys.J.696:176-181,2009
Categories: astro-ph.CO
Related articles: Most relevant | Search more
arXiv:1112.1438 [astro-ph.CO] (Published 2011-12-06)
Search for cold gas in z>2 damped Lyman-alpha systems: 21-cm and H_2 absorption
arXiv:1909.02513 [astro-ph.CO] (Published 2019-09-05)
Searching for the shadows of giants: characterising protoclusters with line of sight Lyman-α absorption
arXiv:1007.0288 [astro-ph.CO] (Published 2010-07-02)
GMRT mini-survey to search for 21-cm absorption in Quasar-Galaxy Pairs at z~0.1