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Related papers: Strong, Variable Circular Polarization in PKS 1519…

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The radio transient ASKAP J173608.2-321735, at the position (l,b)= (356.0872,-0.0390), was serendipitously observed by The HI/OH/Recombination Line Survey of the Galactic Center (THOR-GC) at three epochs in March 2020, April 2020 and…

Short time-scale flux density variations of flat spectrum radio sources are often explained by the scattering of radio waves in the turbulent, ionized Interstellar Matter of the Milky Way. One of the most convincing observational arguments…

Cosmology and Nongalactic Astrophysics · Physics 2013-09-26 K. E. Gabanyi , N. Marchili , T. P. Krichbaum , L. Fuhrmann , P. Muller , J. A. Zensus , X. Liu , H. G. Song

The bright, strongly variable BL Lac object PKS 2155-304 was observed by XMM for two essentially uninterrupted periods of ~11 and 16 hr on 30-31 May 2000. The strongest variations occurred in the highest energy bands. After scaling for this…

Monitoring results are presented for the Stangellini 1 Jy GHz-peaked-spectrum source sample, illustrating that several members exhibit variability in total flux and/or linear polarization over timescales of order a decade. The variability…

Astrophysics · Physics 2007-05-23 M. F. Aller , H. D. Aller , P. A. Hughes , R. M. Plotkin

We derive the distribution of flux density of a compact source exhibiting strong diffractive scintillation. Our treatment accounts for arbitrary spectral averaging, spatially-extended source emission, and the possibility of intrinsic…

Instrumentation and Methods for Astrophysics · Physics 2012-08-09 Michael D. Johnson , Carl R. Gwinn

We summarize results from flux density monitoring campaigns performed with the 100 meter radio-telescope at Effelsberg and the VLA during the past 15 yrs. We briefly discuss some of the statistical properties of the rapid variability from…

Astrophysics · Physics 2009-11-07 T. P. Krichbaum , A. Kraus , L. Fuhrmann , G. Cimo , A. Witzel

The search for periodicity in the multi-wavelength high variable emission of blazars is a key feature to understand dynamical processes at work in this class of active galactic nuclei. The blazar PG 1553+113 is an attractive target due to…

We report on the discovery of a source which exhibits over 300% amplitude changes in radio flux density on the period of hours. This source, J1819+3845, is the most extremely variable extragalactic source known in the radio sky. We believe…

Astrophysics · Physics 2009-10-31 J. Dennett-Thorpe , A. G. de Bruyn

The evidence for refractive interstellar scintillation (RISS) being the main cause for rapid intraday variations (Intraday Variability, IDV) in Quasars and BL Lacs has recently become stronger. If IDV is still a complex composition of…

Astrophysics · Physics 2007-05-23 L. Fuhrmann , G. Cimò , T. P. Krichbaum , T. Beckert , A. Kraus , A. Witzel , J. A. Zensus

Context. We present the light curves of six BL Lac objects, PKS 0537-441, PKS 0735+17, OJ 287, PKS 2005-489, PKS 2155-304, W Comae, and of the flat spectrum radio quasar PKS 1510-089, as a part of a photometric monitoring program in the…

High Energy Astrophysical Phenomena · Physics 2015-06-16 Angela Sandrinelli , Stefano Covino , Aldo Treves

We aim to search for evidence of annual modulation in the time scales of the BL Lac object S5 0716+714. The intra-day variability (IDV) observations were carried out monthly from 2005 to 2009, with the Urumqi 25m radio telescope at 4.8 GHz.…

High Energy Astrophysical Phenomena · Physics 2012-07-12 X. Liu , H. -G. Song , N. Marchili , B. -R. Liu , J. Liu , T. P. Krichbaum , L. Fuhrmann , J. A. Zensus

We report observations of the linear polarization of a sample of 49 nearby bright stars measured to sensitivities of between ~1 and 4 x 10^-6. The majority of stars in the sample show measurable polarization, but most polarizations are…

Solar and Stellar Astrophysics · Physics 2015-05-18 Jeremy Bailey , P. W. Lucas , J. H. Hough

Comparing the asymmetry coefficients and scintillation indices for observed time variations of the intensity of the radiation of extragalactic sources and the predictions of theoretical models is a good test of the nature of the observed…

Astrophysics · Physics 2009-11-11 V. I. Shishov , T. V. Smirnova , S. A. Tyul'bashev

The polarization of fast radio bursts (FRBs), bright astronomical transients, contains crucial information about their environments. We report polarization measurements of five repeating FRBs, the abundant signals of which enable wide-band…

We analyse the circular polarisation data accumulated in the first 7 years of the POLAMI project introduced in an accompanying paper (Agudo et al.). In the 3mm wavelength band, we acquired more than 2600 observations, and all but one of our…

We present the results of variability power spectral density (PSD) analysis using multiwavelength radio to GeV\,$\gamma$-ray light curves covering decades/years to days/minutes timescales for the blazars 3C 279 and PKS 1510-089. The PSDs…

From the analysis of more than 92 ks of data obtained with the laxpc instrument on board Astrosat we have detected a clear high-frequency QPO whose frequency varies between 67.4 and 72.3 Hz. In the classification of variability classes of…

High Energy Astrophysical Phenomena · Physics 2019-08-14 Tomaso M. Belloni , Dipankar Bhattacharya , Pietro Caccese , Varun Bhalerao , Santosh Vadawale , J. S. Yadav

Close binary systems often show linear polarization varying over the binary period, usually attributed to light scattered from electrons in circumstellar clouds. One of the brightest close binary systems is Spica (Alpha Virginis) consisting…

Solar and Stellar Astrophysics · Physics 2019-04-03 Jeremy Bailey , Daniel. V. Cotton , Lucyna Kedziora-Chudczer , Ain De Horta , Darren Maybour

New polarimetric observations of the Crab pulsar at frequencies between 1.4 and 8.4 GHz are presented. Additional pulse components discovered in earlier observations (Moffett & Hankins 1996, astro-ph/9604163) are found to have high levels…

Astrophysics · Physics 2009-10-31 D. A. Moffett , T. H. Hankins

Studies of the pulsar B0823+26 have been carried out using the Large Phased Array (LPA) radio telescope. At time span of 5.5 years, the amplitudes of the main pulse (MP), postcursor (PC) and interpulse (IP) were evaluated in daily sessions…

High Energy Astrophysical Phenomena · Physics 2023-11-10 M. O. Toropov , S. A. Tyul'bashev , T. V. Smirnova , V. A. Samodurov , I. L. Ovchinnikov
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