Results 61 to 70 of about 272 (130)
Propagation of Very-high-energy γ-Rays from Distant Blazars
The Astrophysical Journal, 2023 We rederive the possible dependence of the redshift with a very-high-energy (VHE) γ -ray photon index. The results suggest that the universe to VHE γ -rays is becoming more transparent than expected.
L. J. Dong, Y. G. Zheng, S. J. Kang
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On the Cosmological Evolution of BL Lacertae Objects
The Astrophysical Journal, 2002 We study the cosmological evolution of BL Lac objects by applying the Ve/Va analysis to a new sample of 55 objects, presented for the first time in this paper. This sample has been selected from the 239 sources with the brightest X-ray flux (≥4 × 10-13 ergs s-1 cm-2) and relatively bright optical counterparts (B ≤ 20.5) among the ~1600 objects included
A. Caccianiga +4 more
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VLBI Observations of Nearby HBLs: Physical Implications
GalaxiesWe review the jet kinematics of HBL blazars based on results of the MOJAVE survey, which obtained images of active galactic nuclei with the Very Long Baseline Array (VLBA) at 15 GHz, and the VLBA-BU-BLAZAR program as well as its successor BEAM-ME program,
Svetlana G. Jorstad +2 more
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The Radio Properties of BL Lacertae Objects [PDF]
Symposium - International Astronomical Union, 1980 A recent study of the properties of BL Lacertae Objects at λλ6 and 21 cm by K.J. Johnston and myself has shown:
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Open Astronomy, 2016 Flux density variations of the extragalactic radio source OJ 287 are studied by applying the wavelet and the singular spectrum methods to the long-term monitoring data at 14.5, 8.0 and 4.8 GHz acquired at the University of Michigan Radio Astronomy ...
Donskykh Ganna
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Multiwavelength Variability and Jet Properties of Low-synchrotron-peaked BL Lacertae Objects
The Astrophysical JournalLow-synchrotron-peaked BL Lac objects (LBLs) are promising candidates for masquerading BL Lacs, and the mechanism responsible for their high-energy γ -ray emission still requires further investigation.
R. X. Zhou +4 more
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Multi-messenger emission characteristics of blazars
Frontiers in Astronomy and Space SciencesMulti-messenger observations and theories of astrophysical objects are rapidly becoming a critical research area in the astrophysics scientific community. In particular, point-like objects such as BL Lacertae (BL Lac) objects, flat-spectrum radio quasars
Ronald Gamble +10 more
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The Cosmological Evolution of BL Lacertae Objects
, 2000 We review the main results from several radio, X-ray and multi-frequency surveys on the topic of cosmological evolution of BL Lacertae objects. Updated findings on BL Lac evolution following the recent identification of many sources in the ``Sedentary Multi-Frequency survey'' are also discussed.
Giommi, P. +3 more
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The radio variability of BL Lacertae objects
The Astronomical Journal, 1983 New measurements of the 2380-MHz flux density of 39 radio sources, 31 of which belong to the BL Lacertae class, are presented. These measurements are compared with previous ones made during the first six months of 1979, thereby extending the time base to over 2.5 yr.
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Discerning Misclassified Flat-spectrum Radio Quasars from Low-frequency-peaked BL Lacertae Objects
The Astrophysical Journal Supplement SeriesA sample of 312 low-frequency-peaked BL Lacertae objects (LBLs) and 694 flat-spectrum radio quasars (FSRQs) with the parameters of both redshift and gamma-ray photon spectral index (Γ _γ ) is compiled from the Fourth Catalog of Active Galactic Nuclei ...
S. Liang +3 more
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