Results 21 to 30 of about 272 (130)
The Evolution of the BL Lacertae Objects [PDF]
The Astrophysical Journal, 1999 The BL Lac population is set apart from the rest of the active galactic nuclei by a number of peculiar features, including remarkably little signs of cosmological evolution. We focus on this feature, and take hint from the observations to reconsider extraction of the primary energy from a Kerr hole via the Blandford-Znajek (BZ) process; in fact, we ...
Cavaliere, A., Malquori, D.
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NuSTAR View of TeV Blazar Mrk 501
Galaxies, 2020 We report the results of flux and spectral variability studies of all seven Nuclear Spectroscopic Telescope Array (NuSTAR) observations of TeV γ-ray emitting blazar Markarian (or Mrk) 501.
Ashwani Pandey
doaj +1 more source
A Small-scale Structure Model of a Jet Based on Observations of Microvariability
The Astrophysical Journal Supplement Series, 2023 We developed a multiregion radiation model for the evolution of flux and spectral index with time. In this model, each perturbation component in the jet produces an independent flare.
Jingran Xu +4 more
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The Microvariable Activity of BL Lacertae
Galaxies, 2020 We report on seven nights of optical observation taken over a two-week period, and the resultant analysis of the intermediate-frequency peaked BL Lac object (IBL), BL Lac itself, at redshift z = 0.069. The microvariable behavior can be confirmed over the
Alberto C. Sadun +3 more
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Understanding BL Lacertae objects [PDF]
Astronomy and Astrophysics, 2010 Context. We present evidence that parsec-scale jets in BL Lac objects may be significantly distinct in kinematics from their counterparts in quasars. We argued this previously for the BL lac sources 1803+784 and 0716+714 and report here a similar pattern for another well-known BL Lac object, PKS 0735+178, whose nuclear jet is found to exhibit ...
S. Britzen +8 more
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X-ray Flux and Spectral Variability of Blazar H 2356-309
Galaxies, 2020 We present the results of timing and spectral analysis of the blazar H 2356-309 using XMM-Newton observations. This blazar is observed during 13 June 2005–24 December 2013 in total nine observations.
Kiran A. Wani, Haritma Gaur
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THE COSMIC EVOLUTION OFFERMIBL LACERTAE OBJECTS [PDF]
The Astrophysical Journal, 2013 Fermi has provided the largest sample of gamma-ray selected blazars to date. In this work we use a uniformly selected set of 211 BL Lacertae (BL Lac) objects detected by it Fermi during its first year of operation. We have obtained redshift constraints for 206 out of the 211 BL Lacs in our sample making it the largest and most complete sample of BL ...
Ajello, M. +16 more
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IMAGING REDSHIFT ESTIMATES FOR BL LACERTAE OBJECTS [PDF]
The Astrophysical Journal, 2010 15 pages, to appear in the Astrophysical ...
Meisner, Aaron M., Romani, Roger W.
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A Sample-oriented catalogue of BL Lacertae objects [PDF]
Monthly Notices of the Royal Astronomical Society, 1995 To appear in MNRAS, 7 pages, uses mn.tex. Two figures, table in TeX and ASCII format, and macro available at http://itovf2.roma2.infn.it/padovani/catalogue ...
Padovani, Paolo, Giommi, Paolo
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A BL Lacertae Object at a Cosmic Age of 800 Myr [PDF]
The Astrophysical Journal Letters, 2021 Abstract We report the discovery of the BL Lacertae object FIRST J233153.20+112952.11 at redshift >6 using near-infrared spectroscopy and broadband observations in the infrared, submillimeter, and radio wavelengths. The detection of the continuum break at ∼0.92 μm in the near-infrared spectrum of FIRST J233153.20+112952.11 provides an
Ekaterina Koptelova, Chorng-Yuan Hwang
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