Results 61 to 70 of about 277 (132)

Multi-messenger emission characteristics of blazars

open access: yesFrontiers in Astronomy and Space Sciences
Multi-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
doaj   +1 more source

The radio variability of BL Lacertae objects

open access: yesThe 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.
openaire   +1 more source

Multiband Optical Photometric Variability of the Blazar OJ 287 from 2015 to 2025

open access: yesThe Astrophysical Journal Supplement Series
We present the most densely sampled multiband optical photometric observations of the peculiar BL Lacertae object OJ 287 from 2015 to 2025 with a focus on its optical activity on diverse timescales.
Alok C. Gupta   +105 more
doaj   +1 more source

Discerning Misclassified Flat-spectrum Radio Quasars from Low-frequency-peaked BL Lacertae Objects

open access: yesThe Astrophysical Journal Supplement Series
A 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
doaj   +1 more source

Multiwavelength Study of Extreme High-energy Peaked BL Lac Source 1ES 0229+200 Using Ultraviolet, X-Ray, and γ-Ray Observations

open access: yesThe Astrophysical Journal
We present a comprehensive analysis of the broadband spectral energy distribution (SED) of the extreme high-energy peaked BL Lac source, 1ES 0229+200. Our study utilizes near-simultaneous data collected at various epochs between 2017 September and 2021 ...
Jyotishree Hota   +3 more
doaj   +1 more source

BL Lacertae Objects: A Short Review

open access: yesCommunications of the Byurakan Astrophysical Observatory, 2019
BL Lacertae objects (BLLs) constitute a class of active galactic nuclei (AGNs) with extreme observational features explained by non-thermal radiation from a relativistic jet nearly pointed along the observer’s line-of-sight. Their spectral energy distribution (SED), extending over 17-19 orders of the frequency, is of non-thermal origin and shows a ...
openaire   +1 more source

The Spectral Variation Behavior of Fermi-LAT Blazars

open access: yesThe Astrophysical Journal
In this study, we analyze the ∼16 yr Fermi-Large Area Telescope data of 160 blazars consisting of 92 flat-spectrum radio quasars (FSRQs), 64 BL Lacertae (BL Lac)–type objects, and 4 blazar-candidates-of-unknown-type objects, and investigate their ...
Junhao Deng, Yunguo Jiang
doaj   +1 more source

The megaparsec-scale environments of BL Lacertae objects

open access: yesThe Astrophysical Journal, 1995
We compare observations of BL Lac megaparsec-scale clustering environments with those for F-R I radio galaxies V and R image data are used to show that the strengths of the clustering measured via spatial cross-correlation amplitude are similar for the two types of galaxies and are consistent with Abel richness class 0. We discuss the implications this
Eric P. Smith, C. P. O'Dea, S. A. Baum
openaire   +1 more source

Revealing High-z Fermi-LAT BL Lacs Using Swift and SARA Data with Photometric Analysis

open access: yesThe Astrophysical Journal
BL Lacertae (BL Lac) objects are a subclass of blazar, distinguished by their featureless optical spectrum. The featureless spectrum presents a challenge in measuring the redshift of the BL Lacs.
Y. Sheng   +14 more
doaj   +1 more source

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