1. Radio follow-up of the γ-ray flaring gravitational lens JVAS B0218+357
- Author
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Talvikki Hovatta, Stefano Ciprini, Roopesh Ojha, E. E. Falco, Marcello Giroletti, Daniele Dallacasa, C. C. Cheung, J. L. Richards, M. Orienti, Walter Max-Moerbeck, F. D'Ammando, A. C. S. Readhead, Stefan Larsson, John McKean, Jeffrey D. Scargle, Cristiana Spingola, Astronomy, Spingola, C., Dallacasa, D., Orienti, M., Giroletti, M., Mckean, J.P., Cheung, C.C., Hovatta, T., Ciprini, S., D'Ammando, F., Falco, E., Larsson, S., Max-Moerbeck, W., Ojha, R., Readhead, A.C.S., Richards, J.L., Scargle, J., INAF Istituto di Radioastronomia, University of Groningen, Naval Research Laboratory, Metsähovi Radio Observatory, Agenzia Spaziale Italiana, Harvard-Smithsonian Center for Astrophysics, KTH Royal Institute of Technology, National Radio Astronomy Observatory Socorro, NASA Goddard Space Flight Center, California Institute of Technology, Purdue University, NASA Ames Research Center, Aalto-yliopisto, and Aalto University
- Subjects
Active galactic nucleus ,Astrophysics::High Energy Astrophysical Phenomena ,FOS: Physical sciences ,Owens Valley Radio Observatory ,Astrophysics::Cosmology and Extragalactic Astrophysics ,Astrophysics ,strong [Gravitational lensing] ,01 natural sciences ,law.invention ,Telescope ,law ,0103 physical sciences ,010306 general physics ,Blazar ,010303 astronomy & astrophysics ,Astrophysics::Galaxy Astrophysics ,Very Long Baseline Array ,High Energy Astrophysical Phenomena (astro-ph.HE) ,Physics ,individual: JVAS B0218+357 [Quasars] ,ta115 ,gravitational lensing: strong ,Astronomy ,Astronomy and Astrophysics ,quasars: individual: JVAS B0218+357 ,Light curve ,Astrophysics - Astrophysics of Galaxies ,Gravitational lens ,13. Climate action ,Space and Planetary Science ,Astrophysics of Galaxies (astro-ph.GA) ,Astrophysics - High Energy Astrophysical Phenomena ,Fermi Gamma-ray Space Telescope - Abstract
We present results on multifrequency Very Long Baseline Array (VLBA) monitoring observations of the double-image gravitationally lensed blazar JVAS B0218+357. Multi-epoch observations started less than one month after the gamma-ray flare detected in 2012 by the Large Area Telescope on board Fermi, and spanned a 2-month interval. The radio light curves did not reveal any significant flux density variability, suggesting that no clear correlation between the high energy and low-energy emission is present. This behaviour was confirmed also by the long-term Owens Valley Radio Observatory monitoring data at 15 GHz. The milliarcsecond-scale resolution provided by the VLBA observations allowed us to resolve the two images of the lensed blazar, which have a core-jet structure. No significant morphological variation is found by the analysis of the multi-epoch data, suggesting that the region responsible for the gamma-ray variability is located in the core of the AGN, which is opaque up to the highest observing frequency of 22 GHz., 9 pages, 6 figures, 3 tables. Accepted for publication in MNRAS
- Published
- 2016