H2 emission and CO absorption in Centaurus A: Evidence for a circumnuclear molecular disk

Leiden Repository

H2 emission and CO absorption in Centaurus A: Evidence for a circumnuclear molecular disk

Type: Article / Letter to editor
Title: H2 emission and CO absorption in Centaurus A: Evidence for a circumnuclear molecular disk
Author: Israel, F.P.Dishoeck, E.F. vanBaas, F.Koornneef, J.Black, J.H.Graauw, Th. de
Source: Astronomy and Astrophysics, 227 (2), 342 - 350 (1990)
Issue Date: 1990
Keywords: carbon monoxide
elliptical galaxies
hydrogen clouds
radio sources (astronomy)
absorption spectra
centaurus constellation
density distribution
emission spectra
galactic nuclei
galactic structure
interstellar matter
luminosity
near infrared radiation
Abstract: Emission and absorption lines of H2 and CO in nuclei of several galaxies with strong NIR emission, including Centaurus A (NGC 5128), were studied at the La Silla observatory to obtain constraints on the physical parameters of molecular material close to the nucleus of the NGC 5128 galaxy. Results show that, besides the (C-12)O, and (C-13)O emission and absorption lines toward the nucleus of NGC 5128, an unresolved source of excited H2 emission (of a size smaller than 95 pc) exists that appears to be collisionally excited. The new observations, combined with literature data, suggest that the nucleus of Cen A is surrounded by a disk of mass 2 x 10 to the 7th solar masses. It is shown that a circumnuclear disk with the outer edge at r - 160 pc, a thickness of 80 pc, a cavity with a radius of 40 pc, and a density distribution of about 1/sq r is consistent with all existing observations.
Faculty: Faculteit der Wiskunde en Natuurwetenschappen
Handle: http://hdl.handle.net/1887/1994
 

Files in this item

Description Size View
application/pdf 8_352_033.pdf 1.438Mb View/Open

This item appears in the following Collection(s)