Speaker
Description
Blazars emit powerful electromagnetic (EM) radiation across all wavelengths. The broadband spectral energy distributions (SEDs) of EM emissions from these objects are characterised by two humps. The low frequency hump ranging from radio to infrared/X-ray emission is accepted as synchrotron radiation by primary leptons. The high frequency hump from X-rays to gamma-rays is attributed to inverse-Compton (IC) radiation. Their variable emission, on timescales as short as minutes, constrains the emitting region to a compact size relative to the scale of the host galaxy. The sub-class of blazars known as the flat-spectrum radio quasars (FSRQs) also show strong emission lines in the optical-ultraviolet (UV) spectrum in the broad-line region (BLR). The bright FSRQ 3C 279 has a distinct dip feature in the gamma-ray band of its SED. This feature is also present in other blazars. In a previous work we have shown that the BLR can interact with gamma-rays in the jet to produce secondary electron-positron (e+-) pairs. We also found that, given a sufficiently strong magnetic field in the jet, synchrotron self-Compton (SSC) emission from the e+- pairs can compensate for the gamma-ray dip in the SED of blazars. In this work we model the broadband SED of 3C 279 using JetSet. We add the SSC component from the e+- pairs produced in the BLR to the SED and constrain the magnetic field in the jet.
