Physical Sciences and Mathematics Commons^™

Vlba Polarization Observations Of Markarian 421 After A Gamma-Ray High State, B. Glenn Piner, Philip G. Edwards

Physics

We present four high dynamic range, dual-circular polarization, Very Long Baseline Array (VLBA) observations at 22 GHz of Mrk 421, taken throughout the year following the source's unprecedented gamma-ray high state in early 2001. Previous VLBI observations of this source had shown only subluminal apparent motions in the parsec-scale jet and no apparent connection between jet components and gamma-ray flares, so we examined whether the larger gamma-ray flares of 2001 had produced a component that could be followed on the parsec-scale VLBA images. These four new VLBA observations are combined with data from our earlier 1999 paper and archival VLBA …