The radio continuum spectrum of Centaurus A's large-scale components

Citation
H. Alvarez et al., The radio continuum spectrum of Centaurus A's large-scale components, ASTRON ASTR, 355(3), 2000, pp. 863-872
Citations number
59
Categorie Soggetti
Space Sciences
Journal title
ASTRONOMY AND ASTROPHYSICS
ISSN journal
00046361 → ACNP
Volume
355
Issue
3
Year of publication
2000
Pages
863 - 872
Database
ISI
SICI code
0004-6361(200003)355:3<863:TRCSOC>2.0.ZU;2-5
Abstract
Using our own observations at 45 MHz and data found in the literature after an exhaustive search, we have attempted a comprehensive study of the integ rated flux density spectrum of the Centaurus A radio galaxy and of its larg e scale components. The spectrum for the whole object, between 10 and 4750 MHz, can be well represented by a power law with a spectral index of -0.70 +/- 0.01, disproving the existence of a spectral break reported by other au thors in the past. Between 406 and 4750 MHz we present, for the first time, the spectra of the individual Giant Outer Lobes and find that, within the errors of measurement, their spectral indices are practically equal. We sho w that the Giant Outer Lobes contribute with 73% of the total luminosity of the object. That the indices of the different large scale components are c lose or equal supports the double injection hypothesis for their origin. We discuss the spectral indices and luminosities, and we determine upper boun ds for the ages of the radiating electrons. We show that Centaurus A suppor ts the P-alpha rather than the z-alpha: correlation.