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The mis-aligned active galactic nuclei (AGN), 3C\,84, has been observed approximately monthly at four frequencies simultaneously (22\,GHz -- 129\,GHz) on the Korean VLBI Network (KVN) since 2013 as part of the interferometric monitoring of…

High Energy Astrophysical Phenomena · Physics 2016-12-26 Jeffrey A. Hodgson , S. S. Lee , B. Rani , J. C. Algaba

3C 84 is a nearby Active Galactic Nucleus (AGN) that is unique in that is believed that we are observing near the true jet launching region - unlike blazars. The source is active in Gamma rays and has been detected with Fermi since its…

High Energy Astrophysical Phenomena · Physics 2018-02-09 Jeffrey A. Hodgson , Bindu Rani , Junghwan Oh

The radio galaxy 3C 84 is a representative of gamma-ray-bright misaligned active galactic nuclei (AGNs) and one of the best laboratories to study the radio properties of the sub-pc jet in connection with the gamma-ray emission. In order to…

Following the discovery of a new radio component right before the GeV \gamma-ray detection since 2008 August by Fermi Gamma-ray Space Telescope, we present a detailed study of the kinematics and lightcurve on the central sub-pc scale of 3C…

The radio galaxy 3C84 is a representative of gamma-ray-bright misaligned active galactic nuclei (AGN) and one of the best laboratories to study the radio properties of subparsec scale jets. We discuss here the past and present activity of…

The Broad Line Radio Galaxy 3C 111, characterized by a Fanaroff-Riley II (FRII) radio morphology, is one of the sources of the Misaligned Active Galactic Nuclei sample, consisting of Radio Galaxies and Steep Spectrum Radio Quasars, recently…

High Energy Astrophysical Phenomena · Physics 2015-06-04 Paola Grandi , Eleonora Torresi , Carlo Stanghellini

We present the results of multi-epoch, multi-frequency monitoring of a blazar 4C +29.45, which was regularly monitored as part of the Interferometric Monitoring of GAmma-ray Bright Active Galactic Nuclei (iMOGABA) program - a key science…

High Energy Astrophysical Phenomena · Physics 2021-07-21 S. Kang , S. -S. Lee , J. Hodgson , J. -C. Algaba , J. W. Lee , J. -Y. Kim , J. Park , M. Kino , D. Kim , S. Trippe

We present six-year multi-wavelength monitoring result for broad-line radio galaxy 3C 120. The source was sporadically detected by Fermi-LAT and after the MeV/GeV gamma-ray detection the 43 GHz radio core brightened and a knot ejected from…

High Energy Astrophysical Phenomena · Physics 2019-08-14 Y. T. Tanaka , A. Doi , Y. Inoue , C. C. Cheung , L. Stawarz , Y. Fukazawa , M. A. Gurwell , M. Tahara , J. Kataoka , R. Itoh

We analyze the long-term evolution of the fluxes of six active galactic nuclei (AGN) - 0923+392, 3C 111, 3C 273, 3C 345, 3C 454.3, and 3C 84 - in the frequency range 80-267 GHz using archival calibration data of the IRAM Plateau de Bure…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-28 S. Trippe , M. Krips , V. Pietu , R. Neri , J. M. Winters , F. Gueth , M. Bremer , P. Salome , R. Moreno , J. Boissier , F. Fontani

We present the results of a broadband radio-to-GeV observing campaign organized to get a better understanding of the radiation processes responsible for the $\gamma$-ray flares observed in 3C 279. The total intensity and polarization…

High Energy Astrophysical Phenomena · Physics 2016-10-26 B. Rani , T. P. Krichbaum , S. -S. Lee , K. Sokolovsky , S. Kang , D. -Y. Byun , D. Mosunova , J. A. Zensus

Due to its powerful radiation over the entire electromagnetic spectrum and its radio jet activity, the blazar 3C273 offers the opportunity to study the physics of $\gamma$-ray emission from active galactic nuclei. Since a historically…

High Energy Astrophysical Phenomena · Physics 2020-04-22 Dae-Won Kim , Sascha Trippe , Evgeniya V. Kravchenko

The nearby bright radio galaxy 3C 84 at the center of Perseus cluster is one of the ideal targets to explore the jet in active galactic nuclei (AGNs) and its parsec-scale environment. A recent research of Fujita & Nagai revealed the…

Astrophysics of Galaxies · Physics 2020-05-27 Kiyoaki Wajima , Motoki Kino , Nozomu Kawakatu

In this paper, we conduct a multi-frequency analysis of the gamma-ray bright blazar 1308+326 from February 2013 to March 2020, using the Korean VLBI Network at 22 and 43 GHz and gamma-ray data from the Fermi Large Area Telescope (LAT). Our…

High Energy Astrophysical Phenomena · Physics 2024-04-12 Shan Li , Sang-Sung Lee , Whee Yeon Cheong

3C 345 is one of the archetypical active galactic nuclei, showing structural and flux variability on parsec scales near a compact unresolved radio core. During the last 2 years, the source has been undergoing a period of high activity…

High Energy Astrophysical Phenomena · Physics 2010-12-14 F. K. Schinzel , A. P. Lobanov , S. G. Jorstad , A. P. Marscher , G. B. Taylor , J. A. Zensus

Active galactic nuclei (AGN) are known for irregular variability on all time scales, down to intra-day variability with relative variations of a few percent within minutes to hours. On such short timescales, unexplored territory, such as…

Astrophysics of Galaxies · Physics 2015-11-27 Taeseok Lee , Sascha Trippe , Junghwan Oh , Do-Young Byun , Bong-Won Sohn , Sang-Sung Lee

We present results of single-epoch very long baseline interferometry (VLBI) observations of gamma-ray bright active galactic nuclei (AGNs) using the Korean VLBI Network (KVN) at 22, 43, 86, and 129~GHz bands, which are part of a KVN key…

Ever since the discovery by the Fermi mission that active galactic nuclei (AGN) produce copious amounts of high-energy emission, its origin has remained elusive. Using high-frequency radio interferometry (VLBI) polarization imaging, we…

High Energy Astrophysical Phenomena · Physics 2018-05-15 B. Rani , S. G. Jorstad , A. P. Marscher

In May - July 2014, the flat spectrum radio quasar 3C 454.3 exhibited strong flaring behaviour. Observations with the Large Area Telescope detector on-board the Fermi Gamma-ray Space Telescope captured the $\gamma$-ray flux at energies 0.1…

High Energy Astrophysical Phenomena · Physics 2016-03-23 Rosemary T. Coogan , Anthony M. Brown , Paula M. Chadwick
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