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Related papers: Radio Polarization of BL Lacertae objects

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In this paper, the historical infrared (JHK) data compiled from the published literature are presented in electronic form for 40 radio selected BL Lacertae objects (RBLs) for the first time. Largest variations are found and compared with…

Astrophysics · Physics 2009-10-31 J. H. Fan , R. G. Lin

We have carried out a multifrequency analysis of the radio variability of blazars, exploiting the data obtained during the extensive monitoring programs carried out at the University of Michigan Radio Astronomy Observatory (UMRAO, at 4.8,…

We report the Imaging X-ray Polarimetry Explorer (IXPE) polarimetric and simultaneous multiwavelength observations of the high-energy-peaked BL Lacertae (HBL) object 1ES 1959+650, performed in 2022 October and 2023 August. In 2022 October…

High Energy Astrophysical Phenomena · Physics 2025-03-28 Luigi Pacciani , Dawoon E. Kim , Riccardo Middei , Herman L. Marshall , Alan P. Marscher , Ioannis Liodakis , Iván Agudo , Svetlana G. Jorstad , Juri Poutanen , Manel Errando , Laura Di Gesu , Michela Negro , Fabrizio Tavecchio , Kinwah Wu , Chien-Ting Chen , Fabio Muleri , Lucio Angelo Antonelli , Immacolata Donnarumma , Steven R. Ehlert , Francesco Massaro , Stephen L. O'Dell , Matteo Perri , Simonetta Puccetti , Giacomo Bonnoli , Pouya M. Kouch , Emmanouil Angelakis , Alexander Kraus , Matteo Bachetti , Luca Baldini , Wayne H. Baumgartner , Ronaldo Bellazzini , Stefano Bianchi , Stephen D. Bongiorno , Raffaella Bonino , Alessandro Brez , Niccoló Bucciantini , Fiamma Capitanio , Simone Castellano , Elisabetta Cavazzuti , Stefano Ciprini , Enrico Costa , Alessandra De Rosa , Ettore Del Monte , Niccoló Di Lalla , Alessandro Di Marco , Victor Doroshenko , Michal Dovčiak , Teruaki Enoto , Yuri Evangelista , Sergio Fabiani , Riccardo Ferrazzoli , Javier A. Garcia , Shuichi Gunji , Jeremy Heyl , Wataru Iwakiri , Philip Kaaret , Vladimir Karas , Fabian Kislat , Jeffery J. Kolodziejczak , Henric Krawczynski , Fabio La Monaca , Luca Latronico , Simone Maldera , Alberto Manfreda , Frédéric Marin , Andrea Marinucci , Giorgio Matt , Tsunefumi Mizuno , C. -Y. Ng , Nicola Omodei , Chiara Oppedisano , Alessandro Papitto , George G. Pavlov , Abel Lawrence Peirson , Melissa Pesce-Rollins , Pierre-Olivier Petrucci , Maura Pilia , Andrea Possenti , Brian D. Ramsey , John Rankin , Ajay Ratheesh , Oliver J. Roberts , Roger W. Romani , Carmelo Sgró , Patrick Slane , Paolo Soffitta , Gloria Spandre , Douglas A. Swartz , Toru Tamagawa , Roberto Taverna , Allyn F. Tennant , Nicholas E. Thomas , Francesco Tombesi , Alessio Trois , Sergey S. Tsygankov , Roberto Turolla , Jacco Vink , Martin C. Weisskopf , Fei Xie , Silvia Zane

We explain the properties of X-ray selected BL Lacertae objects, under the assumption that they constitute the small minority of the BL Lac population with energy cutoff located in the UV/X-ray band, as suggested by their multifrequency…

Astrophysics · Physics 2009-10-22 Paolo Padovani , Paolo Giommi

We present the first polarimetric space VLBI imaging observations at 22 GHz. BL Lacertae was observed in 2013 November 10 with the RadioAstron space VLBI mission, including a ground array of 15 radio telescopes. The instrumental…

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 observed the prototype blazar, BL Lacertae, extensively in optical and radio bands during an active phase in the period 2010--2013 when the source showed several prominent outbursts. We searched for possible correlations and time lags…

We present 5 GHz high resolution VLA observations of 2,127 radio- and X-ray-emitting sources found in both the Green Bank (GB) 5 GHz radio catalog and the ROSAT All-Sky Survey (RASS). We report core flux densities and positions accurate to…

This paper concerns the relationship of BLLacs and flat spectrum weak emission-line galaxies. We compare the weak emission-line galaxies and the BLLacs in a sample of 57 flat spectrum objects (Marcha et al. 1996), using high-frequency radio…

Astrophysics · Physics 2007-05-23 J. Dennett-Thorpe , M. J. Marcha

We present the results of simultaneous VLBA polarisation observations of the BL Lacertae object 0820+225 at 5, 8, and 15 GHz, together with earlier images at 5 GHz. This source has an unusually rich total intensity and polarisation…

Astrophysics · Physics 2009-11-06 D. C. Gabuzda , A. B. Pushkarev , N. N. Garnich

Well-sampled optical and radio light curves of BL Lacertae in B, V, R, I bands and 4.8, 8.0, 14.5 GHz from 1968 to 2014 were presented in this paper. A possible $1.26 \pm 0.05$ yr period in optical bands and a $7.50 \pm 0.15$ yr period in…

High Energy Astrophysical Phenomena · Physics 2015-06-19 Y. C. Guo , S. M. Hu , C. Xu , C. Y. Liu , X. Chen , D. F. Guo , F. Y. Meng , M. T. Xu , J. Q. Xu

In the unified schemes for extragalactic radio sources, the quasars and BL Lac objects are intrinsically similar to the Fanaroff-Riley class II and I radio galaxies respectively, but appear to be different because they are viewed at…

Astrophysics · Physics 2009-10-31 D. J. Saikia

We present here uGMRT band 4 (~650MHz) polarization images of 8 BL~Lac objects belonging to the Palomar-Green (PG) `blazar' sample. A large fraction of the sources (~63%) reveal core-halo radio structures with most of the polarization…

Astrophysics of Galaxies · Physics 2023-10-16 Janhavi Baghel , P. Kharb , T. Hovatta , S. Gulati , E. Lindfors , Silpa S

We study the X-ray spectra of 85 BL Lacertae objects using the hardness ratios as given in the WGA catalogue of {\it ROSAT} sources. This sample includes all WGA BL Lacs with high-quality data and comprises about 50 per cent of presently…

Astrophysics · Physics 2015-06-24 Paolo Padovani , Paolo Giommi

Aims: The ``bright'' High Frequency Peakers (HFPs) sample is a mixture of blazars and intrinsically small and young radio sources. We investigate the polarimetric characteristics of 45 High Frequency Peakers, from the ``bright'' HFP sample,…

Astrophysics · Physics 2009-11-13 M. Orienti , D. Dallacasa

We present a sample of 386 BL Lacertae (BL Lac) candidates identified from 2860 deg^2 of the Sloan Digital Sky Survey (SDSS) spectroscopic database. The candidates are primarily selected to have quasi-featureless optical spectra and low…

We present polarization images of 9 radio-loud (RL) quasars from the VLA B-array at 6 GHz. These quasars belong to the Palomar-Green (PG) "blazar" sample comprising 16 RL quasars and 8 BL Lac objects. Extensive polarization is detected in…

Astrophysics of Galaxies · Physics 2022-12-28 Janhavi Baghel , P. Kharb , Silpa S. , Luis C. Ho , C. M. Harrison

Radio-bright BL Lacertae objects (BLOs) are typically variable and exhibit prominent flaring. We use a sample of 24 BLOs to get a clear idea of their flaring behavior and to find possible commonalities in their variability patterns. Our…

Cosmology and Nongalactic Astrophysics · Physics 2014-11-20 E. Nieppola , T. Hovatta , M. Tornikoski , E. Valtaoja , M. F. Aller , H. D. Aller

Polarization behaviour shows a transition in the pulsar population, where energetic sources with higher spin-down energy loss, $\dot{E} > 10^{34}$ erg~s$^{-1}$, often have fractional linear polarisation ($L/I$) close to 100\%, while below…

High Energy Astrophysical Phenomena · Physics 2025-05-20 Dipanjan Mitra , Rahul Basu , George I. Melikidze

We present soft X-ray spectra of 74 BL Lacertae objects observed with the PSPC detector on board of the ROSAT satellite. The sample contains all BL Lac objects detected during the pointed observation phase as a target or serendipitously. We…

Astrophysics · Physics 2007-05-23 G. Lamer , H. Brunner , R. Staubert