A1 Refereed original research article in a scientific journal
A decade of joint MOJAVE-Fermi AGN monitoring: localization of the gamma-ray emission region
Authors: Kramarenko IG, Pushkarev AB, Kovalev YY, Lister ML, Hovatta Talvikki, Savolainen T
Publisher: OXFORD UNIV PRESS
Publication year: 2022
Journal: Monthly Notices of the Royal Astronomical Society
Journal name in source: MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
Journal acronym: MON NOT R ASTRON SOC
Volume: 510
Issue: 1
First page : 469
Last page: 480
Number of pages: 12
ISSN: 0035-8711
DOI: https://doi.org/10.1093/mnras/stab3358
Web address : https://doi.org/10.1093/mnras/stab3358
Self-archived copy’s web address: https://arxiv.org/abs/2106.08416v2
Preprint address: https://arxiv.org/abs/2106.08416v1
Within the MOJAVE VLBA programme (Monitoring of Jets in AGN with VLBA Experiments), we have accumulated observational data at 15 GHz for hundreds of jets in gamma-ray bright active galactic nuclei since the beginning of the Fermi scientific observations in 2008 August. We investigated a time delay between the flux density of AGN parsec-scale radio emission at 15 GHz and 0.1-300 GeV Fermi LAT photon flux, taken from constructed light curves using weekly and adaptive binning. The correlation analysis shows that radio is lagging gamma-ray radiation by up to 8 months in the observer's frame, while in the source frame, the typical delay is about 2-3 months. If the jet radio emission, excluding the opaque core, is considered, significant correlation is found at greater time lags. We supplement these results with VLBI kinematics and core shift data to conclude that the dominant high-energy production zone is typically located at a distance of several parsecs from the central nucleus. We also found that quasars have on average more significant correlation peak, more distant gamma-ray emission region from the central engine and shorter variability time-scale compared to those of BL Lacertae objects.
