| Name: | Maitreya Kundu |
| Affiliation: | Presidency University, Kolkata |
| Conference ID : | ASI2024_29 |
| Title : | Location of a Large Sample of GeV and Optical Outbursts in the Jets of Blazars |
| Authors : | Maitreya Kundu1,2, Ritaban Chatterjee1, Saugata Barat3 |
| Authors Affiliation: | 1 School of Astrophysics, Presidency University, Kolkata-700073, India
2 Department of Physics, Presidency University, Kolkata-700073, India
3 Anton Pannekoek Institute for Astronomy, University of Amsterdam, Science Park 904, NL 1098 XH Amsterdam, the Netherlands |
| Mode of Presentation: | Poster |
| Abstract Category : | High Energy Phenomena, Fundamental Physics and Astronomy |
| Abstract : | The exact location of the γ-ray emitting region in blazar jets has long been a matter of debate. However, the location has important implications about the emission processes, physical parameters of the jet, as well as the nature of interaction of the jet with the interstellar and intergalactic medium. Diverse conclusions have been drawn by various authors based on a variety of methods applied to different data sets of many blazars, e.g., the location is less than 0.1 pc from the central engine within the broad line region (BLR) or a few or tens of pc downstream beyond the dusty torus or at some intermediate distance. Here we use a method, established by Barat et al (2022), in which the location of the GeV/optical emission is determined using the ratio of energy dissipated during contemporaneous outbursts at those wave bands. We apply it to a total of 32 multi-wavelength outbursts in 8 low synchrotron-peaked blazars, for which suitable R band and GeV data are available. Comparing the results with that of a numerical simulation of blazar emission utilizing the internal shocks model, we find that the location of the GeV/optical emission is beyond the BLR for all cases. We compare the locations determined by our method with those determined by other studies which use different methods such as the shortest timescale of variability or VLBI imaging. We find that our results match in most such cases for which the required data were available. |
