Bolometric luminosities and brightness temperatures of BL Lac Objects and FR I radio galaxies

2012 ◽  
Vol 50 (1) ◽  
pp. 96-100 ◽  
Author(s):  
P. Seal Braun
Keyword(s):  
Radio Galaxies ◽  
Bl Lac Objects ◽  
Brightness Temperatures ◽  
Bl Lac

scholarly journals The Environment of OJ 287: Nearby Galaxies and a Long Optical Jet?

1996 ◽  
Vol 175 ◽  
pp. 47-48
Author(s):  
A. Sillanpää ◽  
L. Takalo ◽  
K. Nilsson ◽  
T. Pursimo ◽  
P. Teerikorpi ◽  
...  
Keyword(s):  
Large Scale ◽  
Radio Galaxies ◽  
Trigger Mechanism ◽  
Galaxy Clustering ◽  
Bl Lac Objects ◽  
Close Interaction ◽  
Relativistic Jet ◽  
Bl Lac ◽  
Nearby Galaxies ◽  
Bl Lacs

A widely accepted model for BL Lac objects is that they are radio galaxies with a relativistic jet pointing almost directly towards us. But we need a clear trigger mechanism for these jets. One possibility is the close interaction between the BL Lac host and the closeby galaxies (e.g. Heckman et al. 1986). This interaction has been seen many times in the case of quasars (Hutchings et al. 1989) but not so much is known about the close surroundings of the BL Lac objects although there has been some pioneer work like Stickel et al. (1993). The problem has usually been that the images are not deep enough and that the seeing has not been so good. To clarify the situation we have started an observing program to get very deep images in the sub-arcsecond seeing conditions from the whole 1 Jy sample (Stickel et al. 1991) of BL Lac objects. The aims of this study are: 1. to search for very close companions to the BL Lacs, 2. to study the large scale galaxy clustering around the BL Lacs and 3. to study the BL Lac hosts themselves.

scholarly journals Low-luminosity BL Lac Objects and Flat-spectrum Radio Galaxies

1998 ◽  
Vol 164 ◽  
pp. 171-172
Author(s):  
M. Bondi ◽  
D. Dallacasa ◽  
M. J. M. Marchã ◽  
C. Stanghellini
Keyword(s):  
Radio Galaxies ◽  
Radio Luminosity ◽  
Bl Lac Objects ◽  
Spectrum Radio ◽  
Bl Lac ◽  
First Results

AbstractWe present first results from a new sample of low radio luminosity flat spectrum radio galaxies.

An Atlas of QSO Spectra

1983 ◽  
Vol 5 (1) ◽  
pp. 2-83 ◽  
Author(s):  
Belinda J. Wilkes ◽  
Alan E. Wright ◽  
David L. Jauncey ◽  
Bruce A. Peterson
Keyword(s):  
Great Majority ◽  
Radio Galaxies ◽  
Optical Spectra ◽  
Selection Effects ◽  
Bl Lac Objects ◽  
Bl Lac ◽  
Statistical Studies ◽  
Low Dispersion ◽  
Radio Survey

We present here the low-dispersion optical spectra of 295 QSO candidates. The great majority of the objects were originally selected as QSOs from the Parkes 2700 MHz radio survey, although we have also included spectra of several optically selected QSOs. A few of the QSO candidates are now better described as radio galaxies and BL Lac objects. This collection of spectra is not suitable for statistical studies unless due consideration is given to selection effects.

scholarly journals Multi-Frequency Studies of Intrinsic Intraday Variability

2001 ◽  
Vol 182 ◽  
pp. 105-111
Author(s):  
Stefan J. Wagner
Keyword(s):  
Electromagnetic Spectrum ◽  
Potential Contribution ◽  
Bl Lac Objects ◽  
High Brightness ◽  
Brightness Temperatures ◽  
Interstellar Scintillation ◽  
Bl Lac ◽  
Radio Wavelength ◽  
Very High ◽  
Intraday Variability

AbstractIntraday variability is detected in Blazars throughout the electromagnetic spectrum. Only radio emission is affected by interstellar scintillation. The characteristics of variability observed at different frequencies are often similar and suggest that intrinsic variations also contribute to the changes detected in the radio wavelength regime. This in turn implies very high brightness temperatures.Unambiguous signatures of scintillation and of intrinsic changes have been identified. The properties of intrinsic variations are reviewed to illustrate their potential contribution to variability in the radio domain. Such intrinsic changes need to be discriminated against when studying scintillation in quasars and BL Lac objects. Observations of scintillating sources and of sources with significant intrinsic IDV suggest interesting modifications to the standard paradigm of AGN.

scholarly journals Optical, Infrared and Ultraviolet Observations of Active Nuclei

1983 ◽  
Vol 6 ◽  
pp. 443-457
Author(s):  
M.S. Longair
Keyword(s):  
Radio Galaxies ◽  
High Energy ◽  
Broad Line ◽  
Narrow Line ◽  
Bl Lac Objects ◽  
Ngc 4151 ◽  
Bl Lac ◽  
Central Energy ◽  
Ultraviolet Observations ◽  
Blue Galaxy

I have been invited to present a brief review of optical, infrared and ultraviolet observations of active nuclei. I will only describe a small sub-set of these observations, in particular those which I believe are most likely to be important in elucidating the properties of the central energy source to which we attribute the origin of all high energy phenomena. I will therefore restrict my remarks to certain aspects of BL Lac objects, optically violently variable quasars, quasars, Seyfert I galaxies and broad line radio galaxies. If we could understand these systems, we should be able to account for most other types of active nuclei, the Seyfert II galaxies, narrow line radio galaxies, all other types of Markarian galaxy, compact blue galaxy, etc. In my view, the recent observations of NGC 4151 provide us with a benchmark against which we should measure all other observations of active nuclei.

The Disk-Jet Link and Unification of FSRQs, BL Lac Objects, and FR Radio Galaxies

2008 ◽  
Vol 120 (867) ◽  
pp. 477-486 ◽  
Author(s):  
Z. H. Xie ◽  
J. M. Hao ◽  
L. M. Du ◽  
X. Zhang ◽  
Z. L. Jia
Keyword(s):  
Radio Galaxies ◽  
Bl Lac Objects ◽  
Bl Lac

scholarly journals Jet/accretion and unification for FSRQs/FRII and BL Lac objects/FRI radio galaxies

2015 ◽  
Vol 357 (2) ◽  
Author(s):  
Yongyun Chen ◽  
Xiong Zhang ◽  
Haojing Zhang ◽  
Dingrong Xiong ◽  
Xiaoling Yu ◽  
...  
Keyword(s):  
Radio Galaxies ◽  
Bl Lac Objects ◽  
Bl Lac

scholarly journals The Environments of Radio Galaxies

1996 ◽  
Vol 175 ◽  
pp. 323-324
Author(s):  
J.E. Pesce ◽  
R. Falomo ◽  
G. Fasano ◽  
R. Scarpa
Keyword(s):  
Radio Galaxies ◽  
Line Of Sight ◽  
Type I ◽  
Bl Lac Objects ◽  
Relativistic Jet ◽  
Bl Lac ◽  
The Galaxy ◽  
Galaxy Environment

In the unified schemes of AGNs BL Lac objects are believed to be Fanaroff-Riley (FR) type I radio galaxies with a relativistic jet aligned to the observer's line of sight (e.g. Urry & Padovani 1995). Kollgaard et al. (1992) and Owen et al. (1995) suggest some FR II sources can also be BL Lac parents. Clearly, isotropic properties such as the galaxy environment of both beamed and unbeamed objects should be identical.

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