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相关论文: Extended radio emission in BL Lac objects - I: the…

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We present the radio detection of 18 BL Lac objects from our survey of over 575 square degrees of sky. These 18 objects are located within 20 arcsec of the X-ray position, of which 11 have a measured red-shift. All candidates are radio…

宇宙学与河外天体物理 · 物理学 2015-05-13 M. W. B. Anderson , M. D. Filipović

We present a radio/optical study of a sample of BL Lac objects at arcsecond and milliarcsecond resolution. The sample consists of 30 nearby (z<0.2) BL Lacs, mostly X-ray selected. These nearby objects are weak in the radio, yet we have…

天体物理学 · 物理学 2007-05-23 M. Giroletti , G. Giovannini , G. B. Taylor , R. Falomo

Models that seek to unify BL Lacs and low-power radio galaxies predict that the two types of object should show similar isotropically emitted X-ray emission. Testing this is usually limited by difficulties in separating strong X-ray…

天体物理学 · 物理学 2009-10-31 M. J. Hardcastle , D. M. Worrall , M. Birkinshaw

We present deep radio images at 1.4 GHz of a large and complete sample of BL Lacertae objects (BL Lacs) selected from the Deep X-ray Radio Blazar Survey (DXRBS). We have observed 24 northern sources with the Very Large Array (VLA) in both…

天体物理学 · 物理学 2009-11-13 Hermine Landt , Hayley E. Bignall

We present a morphological and spectral study of a sample of 99 BL Lacs using the LOFAR Two-Metre Sky Survey Second Data Release (LDR2). Extended emission has been identified at gigahertz frequencies around BL Lacs, but with LDR2 it is now…

We present new optical and near-IR spectroscopy as well as new high dynamic range, arcsecond-resolution VLA radio maps of BL Lacs from the complete radio-selected "1 Jansky" (1Jy) sample (RBLs) for which such data were not previously…

天体物理学 · 物理学 2009-11-06 Travis A. Rector , John T. Stocke

We have used the Very Large Array (VLA) to conduct a survey for radio continuum emission in the sample of 52 Seyfert nuclei selected from the optical spectroscopic galaxy catalog of Ho, Filippenko, and Sargent. This Seyfert sample is the…

天体物理学 · 物理学 2009-07-09 Luis C. Ho , James S. Ulvestad

We present observational results for extragalactic radio sources with milliarcsecond components, obtained with the 600 meter ring radio telescope RATAN-600 from 1st to 22nd December, 1997. For each source, a six frequency broad band radio…

We present simultaneous multifrequency radio observations for a complete subsample of 26 XBLs from the Einstein Extended Medium-Sensitivity Survey, obtained with the Very Large Array (VLA). Spectra are computed using fluxes at 20, 6 and 3.6…

天体物理学 · 物理学 2009-11-10 Francesca Cavallotti , Anna Wolter , John T. Stocke , Travis Rector

We present new radio data completing the imaging for a sample of 30 nearby (z < 0.2) BL Lac objects on parsec and kiloparsec scale. The sample is composed of both high and low luminosity sources and it is therefore an ideal test bed for…

天体物理学 · 物理学 2007-05-23 M. Giroletti , G. Giovannini , G. B. Taylor , R. Falomo

Context. The advent of Fermi is changing our understanding on the radio and gamma-ray emission in Active Galactic Nuclei. Contrary to pre-Fermi ideas, BL Lac objects are found to be the most abundant emitters in the gamma-ray band. However,…

高能天体物理现象 · 物理学 2015-06-17 E. Liuzzo , M. Giroletti , G. Giovannini , B. Boccardi , S. Tamburri , G. B. Taylor , C. Casadio , M. Kadler , G. Tosti , A. Mignano

We present a new sample of 30 nearby (z<0.2) BL Lacs, selected to study the nuclear as well as the large scale properties of low power radio sources. In this first paper, we show and discuss new radio data taken with the VLA (19 objects at…

天体物理学 · 物理学 2009-11-10 M. Giroletti , G. Giovannini , G. B. Taylor , R. Falomo

We present high resolution (arcsecond or better) observations made with the Karl G. Jansky Very Large Array of 123 radio-loud quasars with redshifts in the range $2.5 \leq z \leq 5.28$ that form a complete flux limited sample ($\geq 70$ mJy…

星系天体物理 · 物理学 2014-06-19 Doug B. Gobeille , John F. C. Wardle , C. C. Cheung

We present optical identifications and radio spectra for ten radio sources from two flux-density-complete samples. Radio variability characteristics are presented for four objects. The observations were obtained on the RATAN-600 radio…

天体物理学 · 物理学 2009-11-07 V. Chavushyan , R. Mujica , A. G. Gorshkov , V. K. Konnikova , M. G. Mingaliev , J. R. Valdez

We present a series of new high-sensitivity and high-resolution radio-continuum images of M31 at \lambda=20 cm (\nu=1.4 GHz). These new images were produced by merging archived 20 cm radio-continuum observations from the Very Large Array…

星系天体物理 · 物理学 2015-06-04 T. J. Galvin , M. D. Filipović , E. J. Crawford , N. F. H. Tothill , G. F. Wong , A. Y. De Horta

We have collected emission line ([Oiii] 5007 and Halpha+[Nii]) and radio continuum images for a volume limited (cz <= 3600 km/s) sample of southern Seyfert galaxies. The optical data were obtained at ESO using the 2.2 m, NTT and 3.6 m…

天体物理学 · 物理学 2007-05-23 Z. Tsvetanov , R. Morganti , R. A. E. Fosbury , M. G. Allen , J. Gallimore

We present direct imaging data of 22 ultra steep spectrum radio sources obtained at (or near) a subarcsecond seeing. The basic sample of 40 double radio sources was selected from the RATAN-600 catalogue. The FRII-structure has been…

We present a large sample of 501 radio-selected BL Lac candidates from the combination of the Sloan Digital Sky Survey (SDSS) Data Release 5 optical spectroscopy and from the Faint Images of the Radio Sky at Twenty-Centimeters (FIRST) radio…

We report preliminary results of a visual inspection of ~4300 deg$^2$ covered by 4414 images of the 3-GHz VLA Sky Survey (VLASS, epoch 1.1) in search of extended radio structures. Over 7600 positions were registered, and for a subset of 270…

星系天体物理 · 物理学 2018-08-23 Agueda C. Villarreal Hernández , Heinz Andernach

Cheung identified a sample of 100 candidate X-shaped radio galaxies using the NRAO FIRST survey; these are small-axial-ratio extended radio sources with off-axis emission. Here we present radio images of 52 of these sources that have been…

星系天体物理 · 物理学 2015-09-16 David H. Roberts , Jake P. Cohen , Jing Lu , Lakshmi Saripalli , Ravi Subrahmanyan
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