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We report the results of an XMM-Newton observation of the Narrow-Line Seyfert 1 galaxy Mkn 1239. This optically highly polarized AGN has one of the steepest X-ray spectra found in AGN with alpha-X = +3.0 based on ROSAT PSPC data. The…

Astrophysics · Physics 2009-11-10 D. Grupe , S. Mathur , S. Komossa

We have studied the linear polarization of 86 active galactic nuclei (AGN) in the observed frequency range 80-267 GHz (3.7-1.1mm in wavelength), corresponding to rest-frame frequencies 82-738 GHz, with the IRAM Plateau de Bure…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-18 S. Trippe , R. Neri , M. Krips , A. Castro-Carrizo , M. Bremer , V. Pietu , A. L. Fontana

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

A detailed analysis of the optical polarimetric variability of the TeV blazar 1ES 1959+650 from 2007 October 18 to 2011 May 5 is presented. The source showed a maximum and minimum brightness states in the R-band of 14.08$\pm$0.03 mag and…

We report the discovery of a Broad Absorption Line (BAL) of \sim 10^4 km s-1 in width in the previously known BL Lac object PKS 0138-097, which we tentatively identified as a Mg II BAL. This is the first detection of a BAL, which is…

Cosmology and Nongalactic Astrophysics · Physics 2014-12-24 Zhang Shaohua , Wang Huiyuan , Zhou Hongyan , Wang Tinggui , Jiang Peng

We investigate the nature of the faintest radio sources detected in 3 VLA surveys, to faint limits 8 microJy at 8.5 GHz. Using the Keck Low Resolution Imaging Spectrograph in BRI and the Near Infra Red Camera in K, we image 51 radio…

Astrophysics · Physics 2009-11-07 Nathan Roche , James Lowenthal , David Koo

We report discovery of a compact object at high Galactic latitude. The object was initially identified as a ROSAT All-Sky Survey Bright Source Catalog X-ray source, 1RXS J141256.0+792204, statistically likely to possess a high X-ray to…

Astrophysics · Physics 2009-11-13 R. E. Rutledge , D. B. Fox , A. H. Shevchuk

We present Keck spectropolarimetry of the highly polarized radio-loud quasar 3CR 68.1 (z=1.228, V=19). The polarization increases from 5 in the red (4000 A rest-frame) to >10% in the blue (1900 A rest-frame). The broad emission lines are…

Astrophysics · Physics 2009-10-30 M. S. Brotherton , Beverley J. Wills , Arjun Dey , Wil van Breugel , Robert Antonucci

We present extensive optical, radio and infrared follow-up observations of a sample of 35 hard X-ray (2-10 keV) selected sources discovered serendipitously in the PV XMM-Newton observation of the radio-loud quasar PKS 0312-77 field, for…

We present results of deep polarization imaging at 1.4 GHz with the Dominion Radio Astrophysical Observatory as part of the DRAO Planck Deep Fields project. This deep extragalactic field covers 15.16 square degrees centered at RA = 16h 14m…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-18 Julie Grant , Russ Taylor , Jeroen Stil , Tom Landecker , Roland Kothes , Ryan Ransom , Douglas Scott

Since radio sources with Ultra Steep Spectra (USS; alpha <~ -1.30; S ~ nu^alpha) are efficient tracers of high redshift radio galaxies (HzRGs), we have defined three samples of such USS sources using the recently completed WENSS, TEXAS,…

Astrophysics · Physics 2011-05-23 Carlos De Breuck , Wil van Breugel , Huub Rottgering , George Miley

We use the Very Long Baseline Array to conduct high precision astrometry of a sample of 33 compact, flat spectrum, variable radio sources in the direction of the Galactic plane (Becker et al. 2010). Although Becker et al. (2010) ruled out a…

High Energy Astrophysical Phenomena · Physics 2022-10-12 P. Atri , J. C. A. Miller-Jones , A. Bahramian , R. M. Plotkin , T. J. Maccarone , B. Marcote , C. O. Heinke , G. R. Sivakoff , A. Ginsburg , L. Chomiuk

(Abridged) We report on the X-ray and multiwavelength properties of 11 radio-quiet quasars with weak or no emission lines identified by the Sloan Digital Sky Survey (SDSS) with redshift z=0.4-2.5. The distribution of relative X-ray…

We present radio spectral analyses for a sample of 29 radio-quiet (RQ) and three radio-loud (RL) narrow-line Seyfert 1 galaxies (NLS1s) detected with the Australia Telescope Compact Array at both 5.5 GHz and 9.0 GHz. The sample is…

A single very deep $10'$ field has been imaged to $r \sim 26$. There are 2682 galaxies with $23 \le r \le 26$ with a size significantly larger than the seeing disk in the field. After correcting for telescope aberrations, possible guiding…

Astrophysics · Physics 2007-05-23 Jens Verner Villumsen

We investigate the nature of low-luminosity radio-loud active galactic nuclei (RLAGN) selected from the LOFAR Two-metre Sky Survey (LoTSS) first data release (DR1). Using optical, mid-infrared, and radio data, we have conservatively…

Astrophysics of Galaxies · Physics 2024-03-01 J. Chilufya , M. J. Hardcastle , J. C. S. Pierce , J. H. Croston , B. Mingo , X. Zheng , R. D. Baldi , H. J. A. Röttgering

Context. The high intensities and narrow bandwidths exhibited by some astronomical masers make them ideal tools for studying star-forming giant molecular clouds. The water maser transition $J_{K_{-1}K_{1}}=5_{32}-4_{41}$ at 620.701 GHz can…

Astrophysics of Galaxies · Physics 2014-09-05 S. C. Jones , M. Houde , M. Harwit , M. Kidger , A. Kraus , C. McCoey , A. Marston , G. Melnick , K. M. Menten , P. Morris , D. Teyssier , V. Tolls

We report on observations of the optical variability of the radio-loud, narrow-line Seyfert 1 galaxy J0948+0022 on time scales ranging from minutes to years. Implications regarding recent suggestions that the object may constitute a…

High Energy Astrophysical Phenomena · Physics 2015-06-12 Jeremy D. Maune , H. Richard Miller , Joesph R. Eggen

In recent years, several Radio-Loud Narrow-Line Seyfert 1 galaxies (RL-NLS1) possessing relativistic jets have come into attention with their detections in Very Large Baseline Array (VLBA) and in $\gamma$-ray observations. In this paper we…

Astrophysics of Galaxies · Physics 2018-07-09 Veeresh Singh , Hum Chand

A patch of sky in the SDSS Stripe 82 was observed at 1.6 GHz with Very Long Baseline Interferometry (VLBI) using the European VLBI Network (EVN). The data were correlated at the EVN software correlator at JIVE (SFXC). There are fifteen…

Astrophysics of Galaxies · Physics 2014-06-19 H. -M. Cao , S. Frey , L. I. Gurvits , J. Yang , X. -Y. Hong , Z. Paragi , A. T. Deller , Ž. Ivezić
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