Details

Autor(en) / Beteiligte

• Quillen, Alice C
• Bland-Hawthorn, Joss
• Brookes, Mairi H
• Werner, Michael W
• Smith, J. D
• Stern, Daniel
• Keene, Jocelyn
• Lawrence, Charles R

Titel

Discovery of a 500 Parsec Shell in the Nucleus of Centaurus A

Ist Teil von

• The Astrophysical journal, 2006-04, Vol.641 (1), p.L29-L32

Ort / Verlag

Chicago, IL: IOP Publishing

Erscheinungsjahr

2006

Quelle

EZB Electronic Journals Library

Beschreibungen/Notizen

• Spitzer Space Telescope mid-infrared images of the radio galaxy Centaurus A reveal a shell-like, bipolar, structure 500 pc to the north and south of the nucleus. This shell is seen in 5.8, 8.0, and 24 km broadband images. Such a remarkable shell has not been previously detected in a radio galaxy and, if confirmed, would be the first extragalactic nuclear shell detected at mid-infrared wavelengths. Assuming that it is a coherent expanding structure, we estimate that the shell is a few million years old and has a mass on the order of a million solar masses. A conservative estimate for the mechanical energy in the wind-driven bubble is 10 super(53) ergs. The shell could have been created by a small, few-thousand solar mass, nuclear burst of star formation. Alternatively, the bolometric luminosity of the active nucleus is sufficiently large that it could power the shell. Constraints on the shell's velocity are lacking. However, if the shell is moving at 1000 km s super(-1), then the required mechanical energy would be 100 times larger.