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Related papers: Magnetic fields in AGNs and microquasars

200 papers

We present preliminary results on the properties of relativistically broadened Fe K-alpha lines in a collection of more then 100 Active Galactic Nuclei (AGN) observed by the XMM-Newton EPIC-pn camera. Our main conclusions can be summarized…

Astrophysics · Physics 2009-11-11 M. Guainazzi , S. Bianchi , M. Dovciak

Periodic outbursts are observed in several changing-look (CL) active galactic nuclei (AGNs). \citet{sniegowska_possible_2020} suggested a model to explain the repeating CL in these AGNs, where the periodic outbursts are triggered in a…

Astrophysics of Galaxies · Physics 2021-04-07 Xin Pan , Shuang-Liang Li , Xinwu Cao

Observational evidence for strong magnetic fields throughout the envelopes of evolved stars is increasing. Many of the instruments coming on line in the near-future will be able to make further contributions to this field. Specifically,…

Solar and Stellar Astrophysics · Physics 2010-10-07 Wouter Vlemmings

Estimates of the magnetic field of neutron stars in X-ray pulsars are obtained using the hypothesis of the equilibrium period for disk and wind accretion and also from the BATSE data on timing of X-ray pulsars using the observed maximum…

Astrophysics · Physics 2007-05-23 V. M. Lipunov , S. B. Popov

Magnetic fields play a dual role in gamma-ray bursts (GRBs). First, GRB and afterglow spectra (the latter interpreted as emission from external shocks) imply synchrotron radiation in a magnetic field that is a significant fraction of…

Astrophysics · Physics 2007-05-23 Eric G. Blackman

We report a measurement of intergalactic magnetic fields using combined data from Atmospheric Cherenkov Telescopes and Fermi Gamma-Ray Space Telescope, based on the spectral data alone. If blazars are assumed to produce both gamma rays and…

High Energy Astrophysical Phenomena · Physics 2012-04-03 Warren Essey , Shin'ichiro Ando , Alexander Kusenko

Kilo-parsec scale hard ($>$ 3 keV) X-ray continuum and fluorescent Fe K$\alpha$ line emission has been recently discovered in nearby Compton-thick (CT) active galactic nuclei (AGN), which opens new opportunities to improve AGN torus…

High Energy Astrophysical Phenomena · Physics 2023-05-17 Jingzhe Ma , Martin Elvis , G. Fabbiano , Mislav Balokovic , W. Peter Maksym , Guido Risaliti

Observed in a significant fraction of clusters and groups of galaxies, diffuse radio synchrotron emission reveals the presence of relativistic electrons and magnetic fields permeating large-scale systems of galaxies. Although these…

X-ray binary systems are very popular objects for astrophysical investigations. Compact objects in these systems are neutron stars, white dwarfs and black holes. Neutron stars and white dwarfs can have intrinsic magnetic fields. There is…

Solar and Stellar Astrophysics · Physics 2014-09-09 M. Yu. Piotrovich , Yu. N. Gnedin , S. D. Buliga , T. M. Natsvlishvili , N. A. Silant'ev , A. S. Nikitenko

We present X-ray and multiwavelength studies of a sample of eight high-luminosity active galactic nuclei (AGNs) with disc-like H\beta emission-line profiles selected from the Sloan Digital Sky Survey Data Release 7. These sources have…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-12 B. Luo , W. N. Brandt , M. Eracleous , Jian Wu , P. B. Hall , A. Rafiee , D. P. Schneider , Jianfeng Wu

The strength and spectrum of the extragalactic magnetic field are still unknown. Its measurement would help answer the question of whether galactic fields are purely a primordial relic or were dynamically enhanced from a much smaller…

Astrophysics · Physics 2009-10-28 Sangjin Lee , Angela Olinto , Guenter Sigl

The relativistically broadened iron K-alpha line at 6.4 keV observed in the Seyfert 1 galaxy MCG-6-30-15 has provided a probe of the strong-gravity environment near a black hole, in particular suggesting that it is rapidly spinning. An…

Astrophysics · Physics 2009-11-10 R. Goyder , A. N. Lasenby

Notwithstanding the big efforts devoted to the investigation of the mechanisms responsible for the high-energy (E>100 MeV) gamma-ray emission in active galactic nuclei (AGN), the definite answer is still missing. The X-ray energy band…

X-ray observations of several active galactic nuclei show prominent iron K-shell fluorescence lines that are sculpted due to special and general relativistic effects. These observations are important because they probe the space-time…

High Energy Astrophysical Phenomena · Physics 2015-05-14 D. R. Ballantyne

Radio continuum observations of barred galaxies revealed strong magnetic fields of >= 50-100 muG in the circumnuclear starbursts. Such fields are dynamically important and give rise to magnetic stress that causes inflow of gas towards the…

Astrophysics of Galaxies · Physics 2015-06-03 Rainer Beck

Evidence is accumulating suggesting that collisionless shocks in supernova remnants (SNRs) can amplify the interstellar magnetic field to hundreds of microgauss or even milli-gauss levels, as recently claimed for SNR RX J1713.7-3946. If…

Astrophysics · Physics 2009-11-13 Donald C. Ellison , Andrey Vladimirov

We propose a method of measurement of extragalactic magnetic fields in observations of TeV gamma-rays from distant blazars. Multi-TeV gamma-rays are emitted by these sources in narrow jet with opening angle of few degrees. These primary…

Astrophysics · Physics 2008-11-26 A. Neronov , D. V. Semikoz

Synchrotron emission, its polarization and its Faraday rotation at radio frequencies of 0.2-10 GHz are powerful tools to study the strength and structure of cosmic magnetic fields. The observational results are reviewed for spiral, barred…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-27 Rainer Beck

Accreting X-ray pulsars are among the most luminous objects in the X-ray sky. In highly magnetized neutron stars (B~10^12 G), the flow of matter is dominated by the strong magnetic field. The general properties of accreting X-ray binaries…

High Energy Astrophysical Phenomena · Physics 2012-06-15 I. Caballero , J. Wilms

Magnetic fields in the upper atmospheres of solar-like stars are believed to provide an enormous amount of energy to power the hot coronae and drive large-scale eruptions that could impact the habitability of planetary systems around these…