The Linear Accelerating Superluminal Motion Model

Abstract

Accelerating superluminal motions were detected recently by multiepoch very long baseline interferometry observations. Here a linear accelerating superluminal motion (LASM) model is proposed to interpret the observed phenomena. The model provides a direct and accurate way to estimate the viewing angle of a relativistic jet. It also predicts that both Doppler boosting and deboosting effects may take place in an accelerating forward jet. The LASM model is applied to the data of the quasar 3C 273, and the initial velocity, acceleration, and viewing angle of its three components are derived through model fits. The variations of the viewing angle suggest that a supermassive black hole binary system may exist in the center of 3C 273. The gap between the inner and outer jet in some radio-loud active galactic nuclei my be explained in terms of Doppler deboosting effects when the components accelerate to ultrarelativistic speed.

Doppler boosting and de-boosting effects in relativistic jets of AGNs and GRBs

“…• Stage I : The jets are accelerating and boosting, which relates to the bright cores of AGNs and the bursts of GRBs. The initial acceleration of relativistic jets has been detected in 3C 273 by Krichbaum et al (2001) and modeled by Zhou et al (2004). In this stage, γ is usually less than a few tens, and δ increase very quickly.…”

Astrophysics in 2005

“…Quasar 0957 with a period near 12 years is the longest-discussed and probably best-established example. Cases were made this year for 3C 345 with a period of 480 yr (no, Lobanov & Roland 2005 haven't seen more than one), 3C 273 (Zhou et al 2004 using a model for jet acceleration), NGC 4716 (two variable nuclei, 60 pc apart; Maoz et al 2005), PKS 1510-089 (P p days and the 4th minimum arrived on schedule; Wu et al 336 2005d). You might draw two different statistical conclusions from these examples.…”

The apparent velocity and acceleration of relativistically moving objects

“…Astronomical situations in which "superluminal" motion has been observed have been discussed in a number of places as well [Rees(1966); Blandford et al(1977); Blandford and Königl(1979); Rybicki and Lightman(1979); Mirabel and Rodriguez(1994)]. The possibility of relativistic effects being generated by accelerating astronomical objects has also been considered [Zhou et al(2004)].…”