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相关论文: Unification of BL Lac objects, FR I and FR II(G) r…

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We collect multi-wavelength measurements of the nuclear emission of 20 low luminosity FR I radio-galaxies to test the viability of the FR I - BL Lac unifying model. Although poorly sampled, the Spectral Energy Distributions (SED) of FR Is…

天体物理学 · 物理学 2009-11-07 E. Trussoni , A. Capetti , A. Celotti , M. Chiaberge , L. Feretti

We explore the viability of the unification of BL Lacs and FR I radio galaxies by comparing the core emission of radio galaxies with those of BL Lacs, taking advantage of the newly measured optical nuclear luminosity of FR I sources. The…

天体物理学 · 物理学 2007-05-23 Marco Chiaberge , Annalisa Celotti , Alessandro Capetti , Gabriele Ghisellini

We explore the viability of the unification of BL Lacs and FR I radio galaxies by comparing the core emission of radio galaxies with those of BL Lacs of similar extended radio power, taking advantage of the newly measured optical nuclear…

天体物理学 · 物理学 2007-05-23 Marco Chiaberge , Annalisa Celotti , Alessandro Capetti , Gabriele Ghisellini

Our knowledge of Giga-electron volt (GeV) radio galaxies has been revolutionized by the Fermi-LAT Telescope, which provides an excellent opportunity to study the physical properties of GeV radio galaxies. According to the radio power and…

高能天体物理现象 · 物理学 2023-05-18 Xu-Hong Ye , Xiang-Tao Zeng , Dan-Yi Huang , Zhuang Zhang , Zhi-Yuan Pei , Jun-Hui Fan

In this paper, we collect radio and X-ray observations for most Fanaroff-Riley I (FRI) radio galaxies in the Zirbel-Baum radio galaxy sample, and investigate the distribution of the radio-to-X-ray effective spectral index, $\alpha_{rx}$, to…

天体物理学 · 物理学 2009-10-31 J. M. Bai , Myung Gyoon Lee

In this paper: 1. The assumption of the dependence of Doppler factor on the emission frequency (Fan et al. 1993) is used to explain the observational differences between the radio-selected BL Lac objects(RBLs) and the X-Ray-Selected BL Lac…

天体物理学 · 物理学 2016-08-30 J. H. Fan

Hubble Space Telescope (HST) observations provide a novel way of testing unified models for FR I radio sources and BL Lac objects. The detection of extended dust discs in some radio galaxies provides information on their jet orientation.…

天体物理学 · 物理学 2009-10-31 Alessandro Capetti , Annalisa Celotti

Two key results are presented in this paper. First, equipartition Doppler factors have been estimated for a sample of 105 sources with previously estimated inverse Compton Doppler factors. The different categories of active galactic nuclei…

天体物理学 · 物理学 2008-02-03 R. A. Daly , E. J. Guerra , A. Guijosa

In an earlier paper we presented nuclear X-ray flux densities, measured with ROSAT, for the B2 bright sample of nearby low-luminosity radio galaxies. In this paper we construct a nuclear X-ray luminosity function for the B2 radio galaxies,…

天体物理学 · 物理学 2009-11-07 M. J. Hardcastle , D. M. Worrall , M. Birkinshaw , C. M. Canosa

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…

高能天体物理现象 · 物理学 2019-04-10 A. Sandrinelli , R. Falomo , A. Treves

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

We examine the optical properties of the nuclei of low luminosity radio-galaxies using snapshot HST images of the B2 sample. In agreement with the results obtained from the analysis of the brighter 3C/FRI sample, we find a correlation…

天体物理学 · 物理学 2009-11-07 A. Capetti , A. Celotti , M. Chiaberge , H. R. de Ruiter , R. Fanti , R. Morganti , P. Parma

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 have recently proposed a new scenario where blazars are classified as flat-spectrum radio quasars or BL Lacs according to the prescriptions of unified schemes, and to a varying combination of Doppler boosted radiation from the jet,…

宇宙学与河外天体物理 · 物理学 2018-07-11 Paolo Giommi , Paolo Padovani

In a companion paper we presented a statistical model for the blazar population, consisting of distributions for the unbeamed radio luminosity function and the Lorentz factor distribution of each of the BL Lac and Flat Spectrum Radio Quasar…

高能天体物理现象 · 物理学 2015-10-21 I. Liodakis , V. Pavlidou

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

...The distribution of radio core-dominance is consistent with average projection angles of 13.5, 14.8, 16.8, 20.4, and 28.2 for ISPs, LSPs, FSRQs, HSPs, and radio galaxies, respectively. Linear regression analyses of our data yield…

星系天体物理 · 物理学 2021-04-28 E. U. Iyida , F. C. Odo , A. E. Chukwude

The phenomenology of gamma-ray bright blazars can be accounted for by a sequence in the source power and intensity of the diffuse radiation field surrounding the relativistic jet. Correspondingly, the equilibrium particle distribution peaks…

天体物理学 · 物理学 2009-10-30 G. Ghisellini , A. Celotti , G. Fossati , L. Maraschi , A. Comastri

Our understanding of the unification of jetted AGNs has advanced greatly as the size of extragalactic sources increased. In the present paper, based on the large sample of radio sources, we compiled 680 blazars (279 FSRQs and 401 BL Lacs)…

星系天体物理 · 物理学 2021-11-17 E. U. Iyida , I. O. Eya , F. C. Odo

Statistical analyses are invaluable methods used to understand intrinsic emission processes and the unification of extragalactic radio sources. In this paper, we collected radio, X-ray and {\gamma}-ray data of blazars from the Fermi-LAT and…

高能天体物理现象 · 物理学 2021-12-08 E. U. Iyida , I. O. Eya , F. C. Odo
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