Results 21 to 30 of about 277 (132)
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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Advances in Astronomy, Volume 2012, Issue 1, 2012., 2012 Recent polarimetric surveys of extragalactic radio sources (ERS) at frequencies ν ≳ 1 GHz are reviewed. By exploiting all the most relevant data we study the frequency dependence of polarization properties of ERS between 1.4 and 86 GHz. For flat‐spectrum sources the median (mean) fractional polarization increases from 1.5% (2–2.5%) at 1.4 GHz to 2.5–3%
Marco Tucci +2 more
wiley +1 more source
The Rosat X-Ray Spectra of BL Lacertae Objects [PDF]
Symposium - International Astronomical Union, 1996 We have analyzed the X-ray spectra of all BL Lacs observed (as pointed or serendipitous sources) by ROSAT. Spectral indices were obtained from the hardness ratios given in the WGA catalogue, a large list of X-ray sources generated from all the ROSAT PSPC pointed observations. The selection of the objects was done by cross-correlating the first revision
Padovani, Paolo, Giommi, Paolo
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New Observations of BL Lacertae Objects [PDF]
Symposium - International Astronomical Union, 1996 This contribution is divided into three parts: 1. A summary of mostly published work that describes the new type of BL Lac Objects discovered with X-ray satellites, “X-ray Bright BL Lacs (XBLs)”, and their relationship to the previously known “radio bright BL Lacs (RBLs).” Most (but not all?) of the differences between XBLs and RBLs are explicable ...
Mei, D. C. +3 more
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Imaging Redshifts of BL Lacertae Objects [PDF]
The Astrophysical Journal, 2005 The HST snapshot imaging survey of 110 BL Lac objects (Urry et al.) has clearly shown that the host galaxies are massive and luminous ellipticals. The dispersion of the absolute magnitudes is sufficiently small that the measurement of the galaxy brightness becomes a valuable way of estimating their distance. This is illustrated by constructing a Hubble
SBARUFATTI B, TREVES, ALDO, FALOMO R.
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A Tentative Sketch for BL Lacertae Objects [PDF]
Symposium - International Astronomical Union, 1994 VLBI polarization data show magnetic field configuration parallel to the nuclear jet in quasars and perpendicular to it in BL Lac objects. It appears difficult to account for this contrast within the unified scheme for AGN. To investigate a direct explanation of this peculiarity of BL Lac objects, we study the possibilities of propagation and radiation
Hélène Sol, Lourdes Vicente
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Sub-Hour X-Ray Variability of High-Energy Peaked BL Lacertae Objects
Galaxies, 2018 The study of multi-wavelength flux variability in BL Lacertae objects is very important to discern unstable processes and emission mechanisms underlying their extreme observational features. While the innermost regions of these objects are not accessible
Bidzina Kapanadze
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Research of blazars at the Astronomical observatory of Belgrade [PDF]
Serbian Astronomical Journal, 2014 At the beginning of 2013, we have a team of scientists at the Astronomical Observatory of Belgrade, focusing on observations and research of blazars.
Vince O., Damljanović G.
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Statistical Analysis of the Microvariable AGN Source Mrk 501
Galaxies, 2018 We report on the optical observations and analysis of the high-energy peaked BL Lac object (HBL), Mrk 501, at redshift z = 0.033. We can confirm microvariable behavior over the course of minutes on several occasions per night.
Alberto C. Sadun +3 more
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