A spectral analysis of the BL Lac type AGN 1ES 1959+650 in the X-ray, and Gamma-ray energy bands
Active Galactic Nuclei in the Local Universe
Date Submitted
2017-04-13 22:04:08
Mahesh Herath
Udara Abeysekara (University of Utah), Chandana Jayaratne (University of Colombo)
University of Colombo
We report the X-ray, and Gamma ray observations of the BL Lac type Blazar 1ES 1959+650 between mid-2014 and mid-2016. The observed data were extracted from the Fermi-LAT in the energy band of 1-200 GeV and from the Swift-XRT in the energy band of 0.3 - 10 KeV. The Fermi-LAT data was analyzed with the Pass 8 Fermi Science Tools package, and the Swift-XRT data has been analyzed using the Swift web pipeline. Light curves with 24 hour bins were generated for the Gamma-ray and X-ray flux with Test Statistics (TS) > 9. The source shows a highly elevated flux state with high TS values beyond April 2016, when compared to the rest of the light curve. This feature is seen in both the Gamma-ray and X-ray energy bands. The Pearson’s Cross Correlation Coefficient (r) was measured between the Gamma and X-ray flux, and their respective spectral indices. No significant correlation was seen in the Gamma-ray energy band which gave a value of r = 0.02, while the X-ray data showed an anti-correlation with r = -0.604. A joint Spectral Energy Distribution (SED) was constructed for time windows that have simultaneous Gamma-ray and X-ray data. The inspection of the SED shows what may be a positional change between the Synchrotron and Inverse-Compton peaks on different dates. This presents the possibility that the peak power for each waveband varies in response to physical changes in the Blazar emission mechanism, leading to the movement of the Synchrotron peak and the Inverse-Compton peak.
Schedule
id
date time
13:30 - 15:00
14:15
Abstract
A spectral analysis of the BL Lac type AGN 1ES 1959+650 in the X-ray, and Gamma-ray energy bands