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The precessing jet-nozzle scenario previously proposed was applied to model-fit the kinematics of five superluminal components (C19,C20,C21,B5 and B7) of jet-B in blazar 3C345. Based on a specific pattern for the the precessing common…

Astrophysics of Galaxies · Physics 2023-09-04 S. J. Qian

Search for Doppler-boosting effect in flux evolution of superluminal components in blazars has been an important subject, which can help clarify their kinematic and emission properties. The kinematics and flux evolution observed at 15GHz…

Astrophysics of Galaxies · Physics 2023-06-12 S. J. Qian

The kinematics and flux evolution of the superluminal knots in blazar 3C345 were interpreted in the framework of the precessing jet-nozzle scenario with a precessing common helical trajectory-pattern. We show that the jet in 3C345 precesses…

High Energy Astrophysical Phenomena · Physics 2024-02-26 S. J. Qian

The kinematic behavior of superluminal components observed at 43 GHz in blazar 3C454.3 were model-fitted with their light curves interpreted in terms of their Doppler-boosting effect. The relation between the flux evolution of superluminal…

High Energy Astrophysical Phenomena · Physics 2023-06-13 S. J. Qian

The precessing jet-nozzle scenario has been applied to interpret the VLBI-kinematics of twenty-seven superluminal components in blazar 3C345 measured during an about 38-yr period. The superluminal knots could be ejected from a double…

Astrophysics of Galaxies · Physics 2022-02-07 S. J. Qian

The Doppler factor ($\delta$) is a fundamental quality for the relativistic jets from active galactic nuclei (AGNs). It is also fundamental to assessing the number of the entire population of the jetted AGN at high redshift ($z$), and…

High Energy Astrophysical Phenomena · Physics 2025-01-28 Dahai Yan , Haiyun Zhang , Jianeng Zhou , Lijuan Dong

We report a change in the trajectory of a well studied jet component of the quasar 3C279. The component changes in apparent projected speed and direction, and we find it to be moving with a Lorentz factor gamma >~ 15 at an initial angle of…

There appears to be a fundamental problem facing Active Galactic Nuclei jet models that require highly relativistic ejection speeds and small jet viewing angles to explain the large apparent superluminal motions seen in so many of the…

Cosmology and Nongalactic Astrophysics · Physics 2013-01-22 M. B. Bell

Our aim is to show how variable Doppler boosting of an intrinsically variable jet can explain the long-term modulation of 1667 \pm 8 days observed in the radio emission of LSI+61303. The physical scenario is that of a conical, magnetized…

High Energy Astrophysical Phenomena · Physics 2014-02-18 M. Massi , G. Torricelli-Ciamponi

The mechanism for producing gamma-ray quasi-periodic oscillation (QPO) in blazar is unknown. One possibility is the geometric model, in which without the need for intrinsic quasi-periodic variation, the relativistic Doppler factor changes…

High Energy Astrophysical Phenomena · Physics 2018-11-07 Dahai Yan , Jianeng Zhou , Pengfei Zhang , Qianqian Zhu , Jiancheng Wang

Blazars are a subclass of radio-loud active galactic nuclei (AGNs), where the jet is aligned close to the line of sight. Blazars emission is dominated by non-thermal processes, where Doppler boosted radiation originates from a relativistic…

High Energy Astrophysical Phenomena · Physics 2021-08-19 Jakub Juryšek , Vitalii Sliusar , Dimitri Moulin , Roland Walter

We have calculated variability Doppler boosting factors, Lorentz factors, and viewing angles for a large sample of sources by using total flux density observations at 22 and 37 GHz and VLBI data. We decomposed the flux curves into…

Astrophysics · Physics 2009-11-13 T. Hovatta , E. Valtaoja , M. Tornikoski , A. Lähteenmäki

We had earlier shown that for a constant velocity jet the discrepancy between the low speeds indicated by VLBI knot motions and the high Doppler factors inferred from emission of TeV photons could be reconciled if ultrarelativistic jets…

Astrophysics · Physics 2007-07-25 Paul J. Wiita , Gopal-Krishna , Samir Dhurde , Pronoy Sircar

The blazar AO 0235+164 is a key source for studying the interplay between multi-wavelength variability in its light curves and changes in the position angles and apparent velocities of its parsec-scale jet components. In this work, we…

High Energy Astrophysical Phenomena · Physics 2025-08-21 Flavio Benevenuto da Silva Junior , Anderson Caproni

With their jet pointing towards us, blazars are ideal tools to study the physics and structure of extragalactic jets. Their powerful jets are cosmic particle accelerators and are alleged to be one of the production sites of the high-energy…

High Energy Astrophysical Phenomena · Physics 2025-11-25 Claudia M. Raiteri

We compute the effective values of apparent transverse velocity and flux boosting factors for the VLBI radio knots of blazar jets, by integrating over the angular distributions of these quantities across the widths of jets with finite…

Astrophysics · Physics 2009-11-10 Gopal-Krishna , Samir Dhurde , Paul J. Wiita

The long-term evolution of the synchrotron emission from the parsec-scale jet in the quasar 3C345 is analysed, on the basis of multi-frequency monitoring with very long baseline interferometry (VLBI) and covering the period 1979-1994. We…

Astrophysics · Physics 2009-10-31 A. P. Lobanov , J. A. Zensus

We present a new method how to discriminate the matter content of parsec-scale jets of active galactic nuclei. By constraining the kinetic luminosity of a jet from the observed core size at a single very long baseline interferometry…

Astrophysics · Physics 2009-11-10 Kouichi Hirotani

Blazars are among the most powerful extragalactic objects, as a sub-class of active galactic nuclei. They launch relativistic jets and their emitted radiation shows strong variability across the entire electro-magnetic spectrum. The…

High Energy Astrophysical Phenomena · Physics 2015-08-12 C. M. Fromm , L. Fuhrmann , M. Perucho

The quasar 3C345 is one of the best examples of extragalactic jet with superluminal components moving on helical paths. To get better constraints on the jet physics, we have imaged the source at the highest possible resolution, using…

Astrophysics · Physics 2007-05-23 J. Klare , J. A. Zensus , T. P. Krichbaum , A. P. Lobanov , E. Ros
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