Publication Title

Blazar Variability Workshop II: Entering the GLAST Era

Volume

ASP Conference Series, Vol. 350

Publication Date

2006

Document Type

Conference Paper

First and Last Page

163

Abstract

We present multi-epoch Very Long Baseline Array (VLBA) observations at 22 and 43 GHz of the three EGRET blazars 0235+164, 0827+243, and 1406-076. These three blazars had been identified as potentially having apparent speeds exceeding 40c in the snapshot VLBA survey of EGRET blazars by Jorstad et al. (2001). Based on six epochs of full-track VLBA observations of each source during 2002 and 2003, we have measured apparent speeds of 31±6c, 26±4c, and 30±9c in the jets of 0235+164, 0827+243, and 1406-076, respectively (H0=71 km s-1 Mpc-1, Ωm=0.27, and ΩΛ=0.73). We therefore confirm the presence of ultra-relativistic pattern speeds in these three sources, with the implied lower limit to the bulk Lorentz factor from the observed apparent speeds being Γ>∼25-30, if the pattern speeds do not exceed the bulk apparent speed.

Share

COinS