Multi-Wavelength Study of 4C+28.07

Abstract

4C+28.07 is a γ -ray flat-spectrum-radio-quasar-type source. It is often monitored at different frequencies, though long-term multi-wavelength data of this source have not been modeled in detail before. We have analyzed ∼12 yr (2008 August–2020 May) of Fermi-LAT data with a binning of 10 day timescale and observed three distinctive flaring states. Each flaring state consists of different phases of activity, namely, pre-flare, flare, and post-flare regions. γ -ray spectral analysis of these different activity phases has been performed and the best-fit model for its spectra is found to be a log-parabola model. We have also studied the correlation of simultaneous γ -ray light curves with the optical & radio counterparts in these flaring states and report the DCF with 95% significance level. A large time delay is found between radio and gamma-ray data for two flares, indicating two zones of emission. We have fitted the multi-wavelength data with a two-zone leptonic model. In our two-zone leptonic model the maximum required power in the jet is 9.64 × 10 46 erg s −1 , which is lower than its Eddington luminosity 2.29 × 10 47 erg s −1 .