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Related papers: A Kpc-scale Radio Polarization Study of PG BL Lacs…

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We present results from our radio polarimetric study with the upgraded Giant Metrewave Radio Telescope (uGMRT) at Band 4 (550-850 MHz) of 3 blazars: radio-loud quasars 3C390.3, 4C71.07 and BL Lac object 1ES 2344+514. The aim of this study…

Astrophysics of Galaxies · Physics 2022-11-30 Janhavi Baghel , Silpa S. , P. Kharb , B. Sebastian , P. Shastri

We present polarization images with the Karl G. Jansky Very Large Array (VLA) in A and B-array configurations at 6 GHz of 7 radio-loud (RL) quasars and 8 BL Lac objects belonging to the Palomar-Green (PG) `blazar' sample. This completes our…

Astrophysics of Galaxies · Physics 2024-11-12 Janhavi Baghel , P. Kharb , T. Hovatta , Luis C. Ho , C. Harrison , E. Lindfors , Silpa S. , S. Gulati

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

With high-sensitivity kiloparsec-scale radio polarimetry, we can examine the jet-medium interactions and get a better understanding of the blazar divide in radio-loud (RL) AGN. We are analyzing the radio polarimetric observations with the…

Astrophysics of Galaxies · Physics 2023-04-25 Janhavi Baghel , P. Kharb , Silpa S. , Luis C. Ho , C. M. Harrison

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 very long baseline interferometry polarization images of an X-ray selected sample of BL Lacertae objects belonging to the first High Energy Astronomy Observatory (HEAO-1) and the ROSAT-Green Bank (RGB) surveys. These are…

Astrophysics · Physics 2009-11-13 P. Kharb , D. Gabuzda , P. Shastri

A significant fraction of compact radio-loud quasars display most of the characteristics of relativistically beamed, high-optical polarization blazars, yet are weakly polarized in the optical regime. We have used the VLBA at 22 and 43 GHz…

Astrophysics · Physics 2009-10-31 Matthew L. Lister , Paul S. Smith

We present polarization-sensitive images from the Karl G. Jansky Very Large Array (VLA) at 5 GHz of 11 radio-quiet PG quasars. Based on the radio morphology, spectral index and polarization properties from the VLA study, coupled with the…

Astrophysics of Galaxies · Physics 2024-02-21 Silpa S. , P. Kharb , Luis C. Ho , C. M. Harrison

We present the results of the first survey and monitoring study of the linear polarisation properties of compact, flat-spectrum radio sources at millimetre/submillimetre wavelengths and discuss the implications of the inferred magnetic…

Astrophysics · Physics 2015-06-24 R. Nartallo , W. K. Gear , A. G. Murray , E. I Robson , J. H. Hough

We present results from a combined radio polarization and emission line study of five type 2 quasars at $z<0.2$ with the Karl G. Jansky Very Large Array (VLA) B-array at 5 GHz and Hubble Space Telescope (HST) [O III] observations. These…

Astrophysics of Galaxies · Physics 2022-07-19 Silpa Sasikumar , P. Kharb , C. M. Harrison , A. Girdhar , D. Mukherjee , V. Mainieri , M. E. Jarvis

We report radio imaging and monitoring observations in the frequency range 0.235 - 2.7 GHz during the flaring mode of PKS 2155-304, one of the brightest BL Lac objects. The high sensitivity GMRT observations not only reveal extended…

High Energy Astrophysical Phenomena · Physics 2016-10-19 M. Pandey-Pommier , S. Sirothia , P. Chadwick , J. -M. Martin , P. Colom , W. van Driel , F. Combes , P. Kharb , P-J. Crespeau , J. Richard , B. Guiderdoni

In the framework of the unification scheme of radio-loud active galactic nuclei, BL Lac objects and quasars are the beamed end-on counterparts of low-power (FRI) and high-power (FRII) radio galaxies, respectively. Some BL Lacs have been…

Astrophysics of Galaxies · Physics 2015-06-18 Natalia Zywucka , Arti Goyal , Marek Jamrozy , Michal Ostrowski , Lukasz Stawarz

Blazars are highly variable active galactic nuclei which emit radiation at all wavelengths from radio to gamma-rays. Polarized radiation from blazars is one key piece of evidence for synchrotron radiation at low energies and it also varies…

We present the results of EVN and MERLIN 5 GHz observations of nine ultra-high-energy synchrotron peak BL Lacs (UHBLs) selected as all BL Lacs with \textbf{log ($\nu_{\rm peak}/ \rm Hz)>20$} from Nieppola et al.. The radio structure was…

High Energy Astrophysical Phenomena · Physics 2015-06-05 Zhongzu Wu , D. R. Jiang , Minfeng Gu

Ground-space interferometer RadioAstron provides unique opportunity to probe detail structure of the distant active galactic nuclei at $\mu$as scales. Here we report on RadioAstron observations of the BL Lac object S5 0716$+$71, performed…

Astrophysics of Galaxies · Physics 2020-01-09 E. V. Kravchenko , J. L. Gómez , Y. Y. Kovalev , P. A. Voytsik

We present the results from 685 MHz observations with the upgraded Giant Metrewave Radio Telescope (uGMRT) of 22 quasars belonging to the Palomar-Green (PG) quasar sample. Only four sources reveal extended radio structures on $\sim$10-30…

Astrophysics of Galaxies · Physics 2020-12-22 Silpa S. , P. Kharb , L. C. Ho , C. H. Ishwara-Chandra , M. E. Jarvis , C. Harrison

We present the results of EVN+MERLIN VLBI polarization observations of 8 Broad Absorption Line (BAL) quasars at 1.6 GHz, including 4 LoBALs and 4 HiBALs with either steep or flat spectra on VLA scales. Only one steep-spectrum source,…

Astrophysics · Physics 2009-11-13 Y. Liu , D. R. Jiang , T. G. Wang , F. G. Xie

In this paper, using the database of the university of Michigan Radio Astronomy Observatory (UMRAO) at three (4.8 GHz, 8 GHZ, and 14.5 GHz) radio frequencies, we studied the polarization properties for 47 BL Lacertae objects(38 radio…

We present VLA and first-epoch VLBA observations that are part of a program to study the parsec-scale radio structure of a sample of fifteen high-energy-peaked BL Lacs (HBLs). The sample was chosen to span the range of logarithmic X-ray to…

Astrophysics · Physics 2009-11-07 T. A. Rector , D. C. Gabuzda , J. T. Stocke

A small subset of optically selected radio-quiet quasars showing weak or no emission lines may turn out to be the elusive radio-quiet BL Lac objects, or simply be radio-quiet QSOs with a still-forming/shielded broad line region (BLR). High…

High Energy Astrophysical Phenomena · Physics 2018-07-25 Parveen Kumar , H. Chand , R. Srianand , C. S. Stalin , P. Petitjean , Gopal-Krishna
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