Optical variability of PHL 1811 and 3C 273

BeppoSAX observations of 3C 273

Time Variable Faraday Rotation Measures of 3c 273 & 3c 279

Multifrequency polarimetry with the VLBA confirms the previously reported timevarying Faraday rotation measure (RM) in the quasar 3C 279. Variability in the RM and electric vector position angle (EVPA) of the jet component (C4) is seen making it an unreliable absolute EVPA calibrator. 3C 273 is also shown to vary its RM structure on 1.5 year time-scales. Variation in the RM properties of quasar...

Variability of the Centimeter-submillimeter Spectrum and Polarization of 3c 273 during Outburst

Centimeter to submillimeter total Ñux and polarization monitoring data are used to investigate the nature of a prominent Ñare in the quasar 3C 273 during 1995/6. After removal of the quiescent level, the resulting ““ Ñare spectra ÏÏ are well Ðtted by a simple homogeneous synchrotron source model, which in turn allows the movement of the self-absorption turnover to be tracked during the Ñare. Bo...

The Global Jet Structure of the Archetypical Quasar 3C 273

A key question in the formation of the relativistic jets in active galactic nuclei (AGNs) is the collimation process of their energetic plasma flow launched from the central supermassive black hole (SMBH). Recent observations of nearby low-luminosity radio galaxies exhibit a clear picture of parabolic collimation inside the Bondi accretion radius. On the other hand, little is known of the obser...

A Modified Stratified Model for 3c 273 Jet

We present a modified stratified jet model to interpret the observed spectral energy distributions of knots in 3C 273 jet. Based on the hypothesis of the single index of the particle energy spectrum at injection and identical emission processes among all the knots, the observed difference of spectral shape among different 3C273 knots can be understood as a manifestation of deviation of the equi...