other query modes : |
Identifier query |
Coordinate query |
Criteria query |
Reference query |
Basic query |
Script submission |
TAP |
Output options |
Object types |
Help |
2005AJ....130.2473K - Astron. J., 130, 2473-2505 (2005/December-0)
Sub-milliarcsecond imaging of quasars and active galactic nuclei. IV. Fine-scale structure.
KOVALEV Y.Y., KELLERMANN K.I., LISTER M.L., HOMAN D.C., VERMEULEN R.C., COHEN M.H., ROS E., KADLER M., LOBANOV A.P., ZENSUS J.A., KARDASHEV N.S., GURVITS L.I., ALLER M.F. and ALLER H.D.
Abstract (from CDS):
We have modeled the core of each source with an elliptical Gaussian component. For about 60% of the sources, we have at least one observation in which the core component appears unresolved (generally smaller than 0.05 mas) in one direction, usually transverse to the direction into which the jet extends. BL Lac objects are on average more compact than quasars, while active galaxies are on average less compact. Also, in an active galaxy the sub-milliarcsecond core component tends to be less dominant. Intraday variability (IDV) sources typically have a more compact, more core-dominated structure on sub-milliarcsecond scales than non-IDV sources, and sources with a greater amplitude of intraday variations tend to have a greater unresolved VLBA flux density. The objects known to be GeV gamma-ray-loud appear to have a more compact VLBA structure than the other sources in our sample. This suggests that the mechanisms for the production of gamma-ray emission and for the generation of compact radio synchrotron-emitting features are related. The brightness temperature estimates and lower limits for the cores in our sample typically range between 1011 and 1013 K, but they extend up to 5x1013 K, apparently in excess of the equipartition brightness temperature or the inverse Compton limit for stationary synchrotron sources. The largest component speeds are observed in radio sources with high observed brightness temperatures, as would be expected from relativistic beaming. Longer baselines, which can be obtained by space VLBI observations, will be needed to resolve the most compact high brightness temperature regions in these sources.
Abstract Copyright: ∼
Journal keyword(s): Galaxies: BL Lacertae Objects: General - Galaxies: Active - Galaxies: Jets - Galaxies: Quasars: General - Radio Continuum: Galaxies - Surveys
VizieR on-line data: <Available at CDS (J/AJ/130/2473): table1.dat table2.dat>
Errata: erratum vol. 131, p. 2361 (2006)
Simbad objects: 250
To bookmark this query, right click on this link: simbad:2005AJ....130.2473K and select 'bookmark this link' or equivalent in the popup menu