We present VLBA polarization maps of the radio core of BL Lac at 15 and 22 GHz at five epochs between 1995.4-1996.2. The maps show the ejection of a highly polarized ( ~ 25%) superluminal component (v/c ~ 2.5+/-1.4, H=100) starting in mid-1995. The new component is coeval with a large flux outburst. There is a 0.1-0.3 mas difference in core-knot separation between 15 and 22 GHz. The [putative] core component is only weakly polarized. An extended stationary tail extending SW is detected at all epochs. The tail has a remarkably high fractional polarization with a p.a. ~ 90deg rotated with respect to the superluminal knot polarization.
American Astronomical Society Meeting Abstracts #188
- Pub Date:
- May 1996