VLA and VLBI observations of core-dominated quasars

Thesis/Dissertation · Sun Jan 01 04:00:00 EST 1989

OSTI ID:6578248

Kollgaard, R I

High dynamic range VLA observations of the total intensity and linear polarization of 24 powerful, core dominated quasars have been made at 5 GHz, as well as the first millisecond linear polarization observations of 3C 273. For ten quasars the resolution of the VLA was sufficient to reveal details of the compact extended emission surrounding the bright cores. The former all exhibit one sided jets, and most show evidence of diffuse halos. The luminosity of the extended emission is sufficient for those to be Fanaroff-Riley Class II radio sources. This interpretation is confirmed by the linear polarization structure of the jets and terminal hotspots. If these quasars are similar to powerful lobe dominated sources but are oriented with jet axes close to the line of sight, the large degrees of polarization observed in the hotspots suggest that they are travelling at speeds {upsilon} > 0.5c. The superluminal quasar 3C 345 has been imaged with a variety of resolutions. In spite of the bending on the millisecond scale, the author finds that the jet of 3C 345 is very straight for the first 2 and then has two knots which show an abrupt shift in azimuth. The inferred magnetic field in the jet is offset {approximately}30{degree} from a perpendicular orientation with respect to the jet axis. This quasar also appears to have a faint counter jet, with the jet/counter jet luminosity ratio suggesting jet speeds {upsilon} > 0.56c. There is also an asymmetric diffuse halo. Milliarsecond polarization observations of 3C 273 show that the core (component D) is very weakly polarized. Appreciable polarized flux was detected from five of the superluminal components in the jet, with the fractional polarization increasing with distance from D.

• Research Organization: Brandeis Univ., Waltham, MA (USA)
• OSTI ID: 6578248
• Country of Publication: United States
• Language: English

Related Subjects

640102* -- Astrophysics & Cosmology-- Stars & Quasi-Stellar
Radio & X-Ray Sources
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
COSMIC RADIO SOURCES
ELECTROMAGNETIC RADIATION
ENERGY RANGE
HOT SPOTS
IMAGES
INTERFEROMETRY
LUMINOSITY
MAGNETIC FIELDS
MORPHOLOGY
OPTICAL PROPERTIES
PHYSICAL PROPERTIES
PLASMA JETS
POLARIZATION
QUASARS
RADIATIONS
RADIOWAVE RADIATION
RELATIVISTIC RANGE