by National Aeronautics and Space Administration, Goddard Space Flight Center, For sale by the National Technical Information Service in [Greenbelt, Md, Springfield, Va .
Written in English
|Other titles||Determination of the x-ray spectrum of a complete sample of flat-spectrum radio sources.|
|Statement||D.M. Worrall ... [et al.].|
|Series||NASA CR -- 195951., NASA contractor report -- NASA CR-195951.|
|Contributions||Worrall, Diana M., Goddard Space Flight Center.|
|The Physical Object|
Multiband Approach to AGN, Bonn On the Origin of the BL Lac Phenomenon Dominant paradigm Commonly attributed to conference paper by Blandford & Rees (). BL Lacs are viewed close to axis of a relativistic jet. Jet emission is strongly beamed, and swamps any emission line radiation. The BL LAC phenomenon: X-ray observations of transition objects and determination of the x-ray spectrum of a complete sample of flat-spectrum radio sources. By Diana M. Worrall. : Diana M. Worrall. For the BL Lac phenomenon the merging area seems to form the progenitor, while the Seyfert II phenomenon could be triggered by merging events. The role of star burst activity in terms of activity. BL Lac is a blazar, the most energetic type of black-hole-powered galactic core. A black hole is a concentration of mass so dense that not even light can escape its gravitational pull. Supermassive black holes - about million times the mass of our Sun in the case of BL Lac - in these galaxies' cores power jets of electrically charged particles and intense radiation.
based 6 cm \cores" of BL Lac objects is typically domi-nated by the contribution of relatively highly polarised optically thin emission in the inner jet, as proposed by Gabuzda et al. (), with the core itself being much moremodestlypolarisedthanindicatedbygroundobser-vations,m’1¡3%(Gabuzda,Gabuzda&Gomez a,b). A BL Lacertae object or BL Lac object is a type of active galactic nucleus (AGN) or a galaxy with such an AGN, named after its prototype, BL Lacertae. In contrast to other types of active galactic nuclei, BL Lacs are characterized by rapid and large-amplitude flux variability and significant optical polarization. 1 A simplified view of blazars: why BL Lacertae is actually a quasar in disguise* Paolo Padovani, ESO, Germany P. Giommi, G. Polenta, S. Turriziani, V. DʼElia (ASDC), S. Piranomonte (INAF). All BL Lac objects (except one) have at least 2 companions, some of which are bright, within a projected distance of 60 kpc from the BL Lac. In two cases we found 5 companions within 50 kpc.
This volume gives a comprehensible survey of BL Lac objects: contributors summarize observations on these interesting astrophysical objects and present theoretical models to explain them. Understanding these objects should help to give a better insight into the physics of black holes and relativistic plasmas. BL Lac phenomenon: Proceedings of a meeting held at Turku, Finland, June (Astronomical Society of the Pacific conference series) Jan 1, Hardcover. It has become clear in recent years that relativistic beaming is a good explanation for the BL Lac phenomenon. Of studies based on the relativistic beaming model of BL Lac objects, we note that the orientation of jet's axis to the line-of-sight is very small and, therefore, the observed flux emitted from a rapidly moving source is orders of magnitude higher than the flux in its rest-frame:F. Radio and gamma-ray emissions in Active Galactic Nuclei (AGNs) are both related to the presence of relativistic particles in jets. With the advent of the Fermi Large Area Telescope (LAT), and thanks to its large sensitivity up to several GeV, many observational results are changing our understanding of these phenomena. BL Lac objects, which made up only a fraction of the known extragalactic.