A barred spiral at the centre of the giant elliptical radio galaxy Centaurus A

Citation
If. Mirabel et al., A barred spiral at the centre of the giant elliptical radio galaxy Centaurus A, ASTRON ASTR, 341(3), 1999, pp. 667-674
Citations number
40
Categorie Soggetti
Space Sciences
Journal title
ASTRONOMY AND ASTROPHYSICS
ISSN journal
00046361 → ACNP
Volume
341
Issue
3
Year of publication
1999
Pages
667 - 674
Database
ISI
SICI code
0004-6361(199901)341:3<667:ABSATC>2.0.ZU;2-X
Abstract
We report observations at mid-infrared and submillimeter wavelengths of Cen taurus A (Cen A, NGC 5128), the giant elliptical galaxy that harbors the cl osest radio loud Active Galactic Nucleus (AGN) to Earth. The dust emission from the deep interior of Cen A reveals a bisymmetric structure with a diam eter of 5' (5 kpc), centred at the AGN. This structure is remarkably simila r to that of a barred spiral galaxy, with the bar lying in a plane that is tilted similar to 18 degrees from the line of sight. The true nature of the distribution of dust in the inner regions of Cen A is noticeably displaced from the more chaotic and widespread optical obscuration. The barred spira l is a quasi-stable structure formed at the center of the giant elliptical from the tidal debris of a gas-rich object(s) accreted in the past 10(9) ye ars. The total size and mass of interstellar gas in the ban-ed spiral at th e center of Cen A is comparable to the small Local Group spiral galaxy Mess ier 33. The observation of this remarkable structure opens the more general question on whether the dusty hosts of giant radio galaxies like Cen A, ar e "symbiotic" galaxies composed of a barred spiral inside an elliptical, wh ere the bar serves to funnel gas toward the AGN.