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Related papers: Unifying B2 radio galaxies with BL Lac objects

200 papers

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…

Astrophysics · Physics 2009-11-10 Francesca Cavallotti , Anna Wolter , John T. Stocke , Travis Rector

The unification of X-ray and radio selected BL Lacs has been an outstanding problem in the blazar research in the past years. Recent investigations have shown that the gap between the two classes can be filled with intermediate objects and…

Astrophysics · Physics 2011-05-23 V. Beckmann , D. Engels , N. Bade , O. Wucknitz

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 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…

Astrophysics · Physics 2009-11-13 Hermine Landt , Hayley E. Bignall

\textbf{Context.} Deep optical surveys open the avenue for find large numbers of BL Lac objects that are hard to identify because they lack the unique properties classifying them as such. While radio or X-ray surveys typically reveal dozens…

Astrophysics of Galaxies · Physics 2014-09-30 S. D. Kügler , K. Nilsson , J. Heidt , J. Esser , T. Schultz

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…

Astrophysics · Physics 2009-10-31 M. J. Hardcastle , D. M. Worrall , M. Birkinshaw

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,…

High Energy Astrophysical Phenomena · Physics 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 BeppoSAX LECS, MECS, and PDS spectra of eleven X-ray selected BL Lacertae objects. Combining these sources with the ones presented elsewhere we have a sample of 21 BL Lacs from the Einstein Medium Sensitivity and Einstein Slew…

Astrophysics · Physics 2009-11-07 V. Beckmann , A. Wolter , A. Celotti , L. Costamante , G. Ghisellini , T. Maccacaro , G. Tagliaferri

We present a Chandra and XMM-Newton spectral analysis of the nuclei of the radio galaxies and radio-loud quasars from the 3CRR sample in the redshift range 0.1 < z < 0.5. In the range of radio luminosity sampled by these objects, mostly…

Astrophysics · Physics 2009-11-11 M. J. Hardcastle , D. A. Evans , J. H. Croston

The possibility of radio galaxies being random sample of otherwise normal elliptical galaxies is tested. Starting with the observed optical luminosity functions for elliptical galaxies, it is shown that the probability of an elliptical…

Astrophysics · Physics 2007-05-23 Riccardo Scarpa , C. Megan Urry

Empirical evidence suggests that elliptical galaxies hosting a radio source may not be different from normal non-radio ellipticals. To test this possibility, we use Monte Carlo simulations to reproduce the distribution of radio galaxies in…

Astrophysics · Physics 2007-05-23 Riccardo Scarpa , C. Megan Urry

The advent of Fermi is changing our understanding on the radio and gamma-ray emission in Active Galactic Nuclei. In fact, contrary to previous campaigns, Fermi mission reveals that BL Lac objects are the most abundant emitters in gamma-ray…

High Energy Astrophysical Phenomena · Physics 2013-06-05 E. Liuzzo , B. Boccardi , M. Giroletti , G. Giovannini

Using three complete, radio flux limited, blazar samples we compare the LogN-LogS and the preliminary radio luminosity function of the general population of BL Lacs to those of the subclass of high energy synchrotron peaked (HBL) BL Lacs.…

Astrophysics · Physics 2007-05-23 P. Giommi , P. Padovani , M. Perri , H. Landt , E. Perlman

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…

Astrophysics · Physics 2007-05-23 M. Giroletti , G. Giovannini , G. B. Taylor , R. Falomo

Observations at millimetre wavelengths are presented for a representative sample of 22 X-ray-selected BL Lac objects (XBLs). This sample comprises 19 High-energy cutoff BL Lacs objects (HBLs), 1 Low-energy cutoff BL Lac object (LBL) and 2…

Astrophysics · Physics 2009-10-31 J. A. Stevens , W. K. Gear

Investigations of the cluster environment of radio sources have not shown a correlation between radio power and degree of clustering. However, it has been demonstrated that extended X-ray luminosity and galaxy clustering do exhibit a…

Astrophysics · Physics 2009-10-31 N. A. Miller , F. N. Owen , J. O. Burns , M. J. Ledlow , W. Voges

Combining newly identified and previously known BL Lacs from the RASS-Green Bank (RGB) catalog, we present a sample of 127 BL Lacs, the largest ever derived from a single uniform survey. A Complete sample of 33 objects brighter than O=18.0…

We model the X-ray surface brightness distribution of emission associated with Fanaroff & Riley type-II radio galaxies. Our approach builds on the RAiSE dynamical model which describes broadband radio-frequency synchrotron evolution of…

Astrophysics of Galaxies · Physics 2020-03-18 Ross J. Turner , Stanislav S. Shabala

We have optically identified a sample of 56 featureless continuum objects without significant proper motion from the 2dF QSO Redshift Survey (2QZ). The steep number--magnitude relation of the sample, $n(\bj) \propto 10^{0.7\bj}$, is similar…

We investigate the environments of galaxies around BL Lac objects and FR I radiogalaxies, the alleged parent populations of misaligned sources. We compare the environment of a sample of 50 BL Lac objects at 0.1<z<0.33 with that of a sample…

High Energy Astrophysical Phenomena · Physics 2019-04-10 A. Sandrinelli , R. Falomo , A. Treves