Results 31 to 40 of about 1,386,746 (158)
M87: A Misaligned BL Lacertae Object? [PDF]
The Astrophysical Journal, 1998 The nuclear region of M87 was observed with the Faint Object Spectrograph (FOS) on the Hubble Space Telescope (HST) at six epochs, spanning 18 months, after the HST image quality was improved with the deployment of the corrective optics (COSTAR) in 1993 December.
Zlatan I. Tsvetanov +7 more
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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
doaj +1 more source
Investigating the Puzzling Synchrotron Behaviour of Mrk 421
Galaxies, 2016 We investigate the multiwavelength behaviour of the high-energy peaked BL Lac object (HBL) Mrk 421 at redshift z = 0 . 031 in the period 2007–2015.
Maria I. Carnerero +6 more
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A Search for Low‐Luminosity BL Lacertae Objects
The Astrophysical Journal, 1999 Many properties of BL Lacs have become explicable in terms of the "relativistic beaming" hypothesis whereby BL Lacs are FR-1 radio galaxies viewed nearly along the jet axis. However, a possible problem with this model is that a transition population between beamed BL Lacs and unbeamed FR-1s has not been detected.
Rector, Travis A. +2 more
openaire +2 more sources
The First- and Second-Order Fermi Acceleration Processes in BL Lacertae Objects
Galaxies, 2018 BL Lacertae objects constitute a rare class of active galactic nuclei with extreme observational features attributed to the Doppler-boosted emission from a relativistic jet, closely aligned to our line-of-sight.
Bidzina Kapanadze
doaj +1 more source
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.
openaire +2 more sources
VLBI observations of seven BL Lacertae objects from RGB sample
, 2007 We present EVN observations of seven BL Lac objects selected from the RGB sample. To investigate the intrinsic radiation property of BL Lac objects, we estimated the Doppler factor with the VLA or MERLIN core and the total 408 MHz luminosity for a sample
D. R. Jiang +7 more
core +1 more source
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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The “Blazar Sequence” in the TeV Band
The Astrophysical Journal, 2023 The “blazar sequence” has been proposed for more than 20 yr, yet its nature is still unclear. In this work, for the first time we expand this topic to the TeV band by using a sample of 58 TeV blazars, including 48 blazars in the quiescent state and 21 ...
Zhihao Ouyang +9 more
doaj +1 more source
UBVRI observations of BL Lacertae objects
The Astrophysical Journal Supplement Series, 1985 A total of 85 UBVRI observations of BL Lac objects is presented. For most of them, an average continuum can be traced by means of well-defined color indices. These continua are always well reproduced by power laws, strongly supporting the hypothesis of a synchrotron origin of the radiation output, as well as the conclusion that there is no dust in such
M. Moles +3 more
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