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Related papers: Optical EVPA rotations in blazars: testing a stoch…

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We developed a method to separate a long-term trend from observed temporal variations of polarization in blazars using a Bayesian approach. The temporal variation of the polarization vector is apparently erratic in most blazars, while…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-14 Makoto Uemura , Koji S. Kawabata , Mahito Sasada , Yuki Ikejiri , Kiyoshi Sakimoto , Ryosuke Itoh , Masayuki Yamanaka , Takashi Ohsugi , Shuji Sato , Masaru Kino

We have monitored the R-band optical linear polarisation of ten jetted NLSy1 galaxies with the aim to quantify their variability and search for candidate long rotation of the polarisation plane. In all cases for which adequate datasets are…

High Energy Astrophysical Phenomena · Physics 2018-07-30 E. Angelakis , S. Kiehlmann , I. Myserlis , D. Blinov , J. Eggen , R. Itoh , S. Komossa , N. Marchilli , J. A. Zensus

We study the ensemble optical variability of 276 FSRQs and 86 BL Lacs in the Palomar-QUEST Survey with the goal of searching for common fluctuation properties, examining the range of behavior across the sample, and characterizing the…

Cosmology and Nongalactic Astrophysics · Physics 2011-02-11 Anne Bauer , Charles Baltay , Paolo Coppi , Nancy Ellman , Jonathan Jerke , David Rabinowitz , Richard Scalzo

Millimeter-band polarimetry offers a powerful probe of AGN jets, accessing regions less affected by opacity and Faraday rotation than at longer radio wavelengths. As part of the POLAMI program, we have conducted 14 years of 1 mm and 3 mm…

Both leptonic and hadronic emission processes may contribute to blazar jet emission; which dominates in blazars's high energy emission component remains an open question. Some intermediate synchrotron peaked blazars transition from their…

High Energy Astrophysical Phenomena · Physics 2022-06-01 Abel L. Peirson , Ioannis Liodakis , Roger W. Romani

In this paper, we propose a novel minimal physical model to elucidate the long-term stochastic variability of blazars. The model is built on the realistic background of magnetized plasma jets dissipating energy through a turbulent cascade…

High Energy Astrophysical Phenomena · Physics 2024-08-06 Nan Ding , Yunyong Tang , Qiusheng Gu , Rui Xue , Yongyun Chen

It is now known that the emission from radio pulsars can vary over a wide range of timescales, from fractions of seconds to decades. However, it is not yet known if long- and short-term emission variability are caused by the same physical…

High Energy Astrophysical Phenomena · Physics 2019-08-28 Paul Brook , Aris Karastergiou , Simon Johnston

We present the results of a systematic observational campaign designed to search for microvariability in the optical polarization of BL Lac objects. We have observed a sample formed by 8 X-ray-selected and 10 radio-selected sources, looking…

Astrophysics · Physics 2009-11-11 I. Andruchow , G. E. Romero , S. A. Cellone

In this work, a time-dependent modeling is developed to study the emission properties of blazars in the low state. Motivated by various observations, we speculate and assume that numerous discrete radiation zones throughout the jet of a…

High Energy Astrophysical Phenomena · Physics 2023-09-22 Ruo-Yu Liu , Rui Xue , Ze-Rui Wang , Hong-Bin Tan , Markus Böttcher

We carefully examine the depolarization feature of blazars in the optical and near-infrared bands using the sample of Mead et al. Magnetohydrodynamics (MHD) turbulence could be one possible reason for the depolarization of optical/infrared…

High Energy Astrophysical Phenomena · Physics 2017-07-05 Xiaotong Guo , Jirong Mao , Jiancheng Wang

The optical polarization plane of some blazars occasionally exhibits smooth hundred degree long rotations. Multiple theoretical models have been proposed to explain the nature of such events. A deterministic origin of these rotations,…

Blazars are known to display strong and erratic variability at almost all the wavelengths of electromagnetic spectrum. Presently, variability studies at high-energies (hard X-rays, gamma-rays) are hampered by low sensitivity of the…

Verification and validation of fully automated vehicles is linked to an almost intractable challenge of reflecting the real world with all its interactions in a virtual environment. Influential stochastic parameters need to be extracted…

Applications · Statistics 2022-11-22 Katrin Lotto , Thomas Nagler , Mladjan Radic

To determine if the recently launched Imaging X-ray Polarimetry Explorer (IXPE) can follow the polarization variations induced by different particle acceleration mechanisms in blazars jets we simulate observations of a high synchrotron peak…

High Energy Astrophysical Phenomena · Physics 2022-06-29 L. Di Gesu , F. Tavecchio , I. Donnarumma , A. Marscher , M. Pesce-Rollins , M. Landoni

The properties of blazar variability in the radio band are studied using the unique combination of temporal resolution from single dish monitoring and spatial resolution from VLBA imaging; such measurements, now available in all four Stokes…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-20 Margo F. Aller , Hugh D. Aller , Philip A. Hughes

Accessing the ballistic regime of single particles in liquids remains an experimental challenge that shrouds our understanding of the particle-liquid interactions on exceedingly short time scales. We demonstrate the ballistic measurements…

We present multi-epoch optical spectroscopy of seven southern Fermi-monitored blazars from 2008 - 2013 using the Small and Medium Aperture Research Telescope System (SMARTS), with supplemental spectroscopy and polarization data from the…

High Energy Astrophysical Phenomena · Physics 2015-11-11 Jedidah C. Isler , C. M. Urry , C. Bailyn , P. S. Smith , P. Coppi , M. Brady , E. Macpherson , I. Hasan , M. Buxton

We present analysis of the flux and polarization variability of parsec scale radio jets from a dual-frequency, six-epoch, VLBA polarization experiment monitoring 12 blazars. The observations were made at 15 and 22 GHz at bimonthly intervals…

Blazars are thought to possess a relativistic jet that is pointing toward the direction of the Earth and the elect of relativistic beaming enhances its apparent brightness. They radiate in all wavebands from the radio to the gamma-ray bands…

High Energy Astrophysical Phenomena · Physics 2015-02-11 Ryosuke Itoh , Yasushi FUkazawa , Yasuyuki T. Tanaka , Makoto Uemura , Koji S. Kawabata , Hiroshi Akitaya , Kenji Kawaguchi , Yuka Kanda

This article aims at developing a simple, automated test bench procedure to measure polarization rotation of an electromagnetic wave upon propagation through a nonreciprocal medium. A comprehensive measurement approach is developed from the…

Applied Physics · Physics 2022-05-11 Swadesh Poddar , Alexander M. Holmes , George W. Hanson