English
Related papers

Related papers: Precession-induced Variability in AGN Jets and OJ …

200 papers

Jetted Active Galactic Nuclei (AGN) hosting extended photoionized nebulae provide us with a unique view of the timescales associated with AGN activity. Here, we present a new Green Bean galaxy (RGB1) at $z=0.304458\pm0.000007$ with large…

Double-peaked emission lines in the narrow- and/or broad-line spectra of AGN have been suggested to arise due to disky broad/narrow line regions, jet-medium interaction, or the presence of binary supermassive black holes. We present the…

Astrophysics of Galaxies · Physics 2019-02-13 Preeti Kharb , Sravani Vaddi , Biny Sebastian , Smitha Subramanian , Mousumi Das , Zsolt Paragi

Number of monitoring observations of continuum emission from Active Galactic Nuclei (AGNs) have been made in optical--X-ray bands. The results obtained so far show (i) random up and down on timescales longer than decades, (ii) no typical…

Astrophysics · Physics 2007-05-23 T. Kawaguchi , S. Mineshige

The jet cores in blazars are resolved and found to harbour an edge brightened structure where the jet base appears extended at sides compared to its propagation axis. This peculiar phenomenon invites various explanations. We show that the…

High Energy Astrophysical Phenomena · Physics 2023-08-15 Mukesh Kumar Vyas , Asaf Pe'er

Significant positional offsets of the value from 1 mas to more than 10 mas were found previously between radio (VLBI) and optical (Gaia) positions of active galactic nuclei (AGN). They happen preferentially parallel to the parsec-scale jet…

Astrophysics of Galaxies · Physics 2021-01-12 Y. Y. Kovalev , D. I. Zobnina , A. V. Plavin , D. Blinov

We present a new centimeter polarimetric VLBI image of the BL Lac object 0735+178. This source exhibits one of the most pronounced curvatures observed in jets of AGNs, with two sharp apparent bends of 90 degrees within the inner 2…

Galactic outflows are now commonly observed in starburst and active galactic nuclei (AGN) host galaxies. Yet, there is no clear consensus on their physical driving mechanism(s). We have previously shown that AGN radiative feedback, driven…

Astrophysics of Galaxies · Physics 2018-10-17 W. Ishibashi , A. C. Fabian

To constrain the nature and fraction of the ionized gas outflows in AGNs, we perform a detailed analysis on gas kinematics as manifested by the velocity dispersion and shift of the [O III] {\lambda}5007 emission line, using a large sample…

Astrophysics of Galaxies · Physics 2016-02-03 Jong-Hak Woo , Hyun-Jin Bae , Donghoon Son , Marios Karouzos

In this paper, we have modelled the dynamical and emission properties (in the presence of radiative losses and diffusive shock acceleration) of an observed S-shaped radio source (2MASX J12032061+131931) due to a precessing jet. In this…

Astrophysics of Galaxies · Physics 2022-06-22 Gourab Giri , Ravi Pratap Dubey , K. Rubinur , Bhargav Vaidya , Preeti Kharb

We present an analysis of the core linear polarization properties of 387 parsec-scale active galactic nuclei (AGN) jets. Using 15 GHz VLBA data, we revisit the conclusions of the first paper in this series with multi-epoch measurements and…

Astrophysics of Galaxies · Physics 2018-08-16 M. A. Hodge , M. L. Lister , M. F. Aller , H. D. Aller , Y. Y. Kovalev , A. B. Pushkarev , T. Savolainen

Flares in radio-loud AGN are thought to be associated with the injection of fresh plasma into the compact jet base. Such flares are usually strongest and appear earlier at shorter radio wavelengths. Hence, VLBI at mm-wavelengths is best…

High Energy Astrophysical Phenomena · Physics 2021-01-04 R. Schulz , M. Kadler , E. Ros , M. Perucho , T. P. Krichbaum , I. Agudo , T. Beuchert , M. Lindqvist , K. Mannheim , J. Wilms , J. A. Zensus

Several multi-frequency polarization studies have shown the presence of systematic Faraday Rotation gradients across the parsec-scale jets of Active Galactic Nuclei (AGN), taken to be due to the systematic variation of the line-of-sight…

Astrophysics · Physics 2007-08-03 Mehreen Mahmud , Denise Gabuzda , Vladislavs Bezrukovs

The precession phenomenon of the jet in a gamma-ray burst (GRB) is a key probe of the physics of the central engine. Previous studies generally assumed a fixed precession period when analysing the temporal profiles in GRBs; however, the…

High Energy Astrophysical Phenomena · Physics 2025-06-30 Yun-Peng Li , Da-Bin Lin , Guo-Yu Li , En-Wei Liang

We present simultaneous, sub-arcsecond (<=50pc) resolution 5 GHz, 8.4 GHz, and 15 GHz VLA observations of a well-defined sample of sixteen low-luminosity active galactic nuclei (LLAGNs). The radio emission in most of these nuclei does not…

Astrophysics · Physics 2009-11-07 Neil M. Nagar , Andrew S. Wilson , Heino Falcke

The `shock in jet' model for cm-waveband blazar variability is revisited, allowing for arbitrary shock orientation with respect to the jet flow direction, and both random and ordered magnetic field. It is shown that oblique shocks can…

High Energy Astrophysical Phenomena · Physics 2015-05-27 Philip A. Hughes , Margo F. Aller , Hugh D. Aller

Non-thermal emission from Active Galactic Nuclei (AGN) jets extends up-to large scales in-spite of them being prone to a slew of magneto-hydrodynamic instabilities. The main focus of this study is to understand the impact of MHD…

High Energy Astrophysical Phenomena · Physics 2021-06-02 Nikhil Borse , Sriyasriti Acharya , Bhargav Vaidya , Dipanjan Mukherjee , Gianluigi Bodo , Paola Rossi , Andrea Mignone

Previous works concerning active galactic nuclei (AGN) variability (e.g., Blandford \& McKee 1982) have assumed that the emission characteristics of illuminated clouds are purely a function of the instant continuum flux to which they are…

Astrophysics · Physics 2009-10-28 Jason A. Taylor

We explore the formation, energetics, and geometry of relativistic jets along with the variability of their central engine. We study both fast and slowly rotating black holes and address our simulations to active galaxy (AGN) centers and…

High Energy Astrophysical Phenomena · Physics 2022-12-07 A. Janiuk , B. James

Multi-wavelength observations of active galactic nuclei (AGNs) often reveal various time scales of variability. Among these phenomena, "changing-look AGNs" are extreme cases where broad emission lines become faint/bright or even…

Astrophysics of Galaxies · Physics 2023-09-25 Keiichi Wada , Yuki Kudoh , Tohru Nagao

Variability in the X-rays is a key ingredient in understanding and unveiling active galactic nuclei (AGN) properties. In this band flux variations occur on short time scales (hours) as well as on larger times scales. While short time scale…

High Energy Astrophysical Phenomena · Physics 2017-03-08 R. Middei , F. Vagnetti , S. Bianchi , F. La Franca , M. Paolillo , F. Ursini