RAPID INFRARED SPECTRAL VARIABILITY OF 3C 66A IN OUTBURST

Citation
Ja. Dediego et al., RAPID INFRARED SPECTRAL VARIABILITY OF 3C 66A IN OUTBURST, Astronomy and astrophysics, 318(2), 1997, pp. 331-336
Citations number
35
Categorie Soggetti
Astronomy & Astrophysics
Journal title
ISSN journal
00046361
Volume
318
Issue
2
Year of publication
1997
Pages
331 - 336
Database
ISI
SICI code
0004-6361(1997)318:2<331:RISVO3>2.0.ZU;2-P
Abstract
Infrared observations taken during the major outburst seen in 1993 sho w strong evidence of rapid variability in 3C 66A on a time scale of a few hours, with associated variability of the spectral slope on the sa me time scale. A strong (P much greater than 99%) correlation is seen between the flux at 2.2 microns and the spectral index, with the spect rum steepening as the flux rises, the opposite trend to that seen norm ally in blazars. Such rapid variability cannot easily be explained by current relativistic jet models; a better option is black body radiati on from hot spots on the accretion disk, possibly linked to strong mag netic fields, although the rapid time scale of the variation and its e nergetics pose serious problems. One possible solution is to invoke br emsstrahlung radiation from a flare, which is later modified by a high degree of extinction through the disk.