arXiv subjects

Raj Prince

Publications and source records attributed to Raj Prince.

56 records · Page 4Linked to original sources

arXiv2018

Fermi-Large Area Telescope observations of the brightest Gamma-ray flare ever detected from CTA 102

We present a multi-wavelength study of the FSRQ CTA 102 using Fermi-LAT and simultaneous Swift-XRT/UVOT observations. The Fermi-LAT telescope detected one of the brightest flares from this object during Sep, 2016 to Mar, 2017. In the 190 days of observation period the source underwent four major flares. A detailed analysis of the temporal and spectral properties of these flares indicates the flare at MJD 57751.594 has a $γ$-ray flux of (30.12$\pm$4.48)$\times 10^{-6}$ ph cm$^{-2}$ s$^{-1}$ (from 90 minutes binning) in the energy range of 0.1--300 GeV. This has been found to be the highest flux ever detected from CTA 102. Time dependent leptonic modelling of the pre-flare, rising state, flares and decaying state has been done. A single emission region of size $6.5\times 10^{16}$ cm has been used in our work to explain the multi-wavelength spectral energy distributions. During flares the luminosity in electrons increases nearly seventy times compared to the pre-flare state.

astro-ph.HE↗

arXiv2017

Long term study of the light curve of PKS 1510-089 in GeV energies

We have analyzed data from the Flat Spectrum Radio Quasar PKS 1510-089 collected over a period of 8 years from August 2008 to December 2016 with the Fermi-LAT. We have identified several flares of this highly variable source, studied their temporal and spectral properties in detail and compared with previous works on flares of PKS 1510-089. Five major flares and few sub-flares/sub-structures have been identified in our study. The fastest variability time is found to be 1.30$\pm$0.18 hr between MJD 55852.063 and 55852.188 where we estimate the minimum size of the emission region to be $4.85 \times 10^{15}$ cm. In most of the flares the spectral energy distributions are better fitted with Logparabolic distribution compared to simple Power law or Power law with exponential cut-offs. This has strong physics implications regarding the nature of the high energy gamma-ray emission region.

astro-ph.HE↗