2019/05/16 by Juan Carlos Algaba, Algaba, Juan Carlos, Sang-Sung Lee +38
Physics and Astronomy · #Astrophysics and Cosmic Phenomena #Astrophysics of Galaxies (astro-ph.GA) #FOS: Physical sciences #Gamma-ray bursts and supernovae #High Energy Astrophysical Phenomena (astro-ph.HE) #Radio Astronomy Observations and Technology #astro-ph.GA #astro-ph.HE
paper · pdf · doi:10.48550/arxiv.1905.06621
Proceedings for the 14th European VLBI Network Symposium & Users Meeting (EVN 2018) 8-11 October 2018, Granada, Spain
arxiv created 2019/05/16 · openalex publication_date 2019/05/16 · arxiv updated 2019/05/17 · openalex created_date 2020/05/01 · openalex updated_date 2026/07/28
The flat spectrum radio quasar 4C 38.41 showed a significant increase of its radio flux density during the period 2012 March - 2015 August which correlates with gamma-ray flaring activity. Multi-frequency simultaneous VLBI observations were conducted as part of the interferometric monitoring of gamma-ray bright active galactic nuclei (iMOGABA) program and supplemented with additional monitoring observations at various bands across the electromagnetic spectrum. The epochs of the maxima for the two largest gamma-ray flares coincide with the ejection of two respective new VLBI components and the evolution of the physical properties seem to be in agreement with the shock-in-jet model. Derived synchrotron self absorption magnetic fields, of the order of 0.1 mG, do not seem to dramatically change during the flares, and are much smaller, by a factor 10,000, than the estimated equipartition magnetic fields, indicating that the source of the flare may be associated with a particle dominated emitting region.