Hard X-ray variability of active galactic nuclei

Details Hard X-ray variability of active galactic nuclei Hard X-ray variability of active galactic nuclei

Dec 2007

adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2007a%26a...475..827b&link_type=abstract

Astronomy and Astrophysics, Volume 475, Issue 3, December I 2007, pp.827-835

Astronomy and Astrophysics

Astrophysics

19

Galaxies: Active, Galaxies: Seyfert, X-Rays:, Galaxies, Surveys

Scientific paper

Aims:Active Galactic Nuclei are known to be variable throughout the electromagnetic spectrum. An energy domain poorly studied in this respect is the hard X-ray range above 20 keV. Methods: The first 9 months of the Swift/BAT all-sky survey are used to study the 14-195 keV variability of the 44 brightest AGN. The sources have been selected due to their detection significance of >10 σ. We tested the variability using a maximum likelihood estimator and by analysing the structure function. Results: Probing different time scales, it appears that the absorbed AGN are more variable than the unabsorbed ones. The same applies for the comparison of Seyfert 2 and Seyfert 1 objects. As expected the blazars show stronger variability. 15% of the non-blazar AGN show variability of >20% compared to the average flux on time scales of 20 days, and 30% show at least 10% flux variation. All the non-blazar AGN which show strong variability are low-luminosity objects with L(14{-195 keV)} < 1044 erg s-1 Conclusions: Concerning the variability pattern, there is a tendency of unabsorbed or type 1 galaxies being less variable than the absorbed or type 2 objects at hardest X-rays. A more solid anti-correlation is found between variability and luminosity, which has been previously observed in soft X-rays, in the UV, and in the optical domain.

Affiliated with

Also associated with

No associations

Rating

Hard X-ray variability of active galactic nuclei does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with Hard X-ray variability of active galactic nuclei, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Hard X-ray variability of active galactic nuclei will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-1473309