Flashing Superluminal Components in the Jet of the Radio Galaxy 3C120
José-Luis Gómez,1*
Alan P. Marscher,2
Antonio Alberdi,1
Svetlana G. Jorstad,23
Cristina García-Miró1
A 16-month sequence of radio images of the active galaxy 3C120 with
the Very Long Baseline Array reveals a region in the relativistic jet
where superluminal components flash on and off over time scales of
months, while the polarization angle rotates. This can be explained by
interaction between the jet and an interstellar cloud located about 8 parsecs from the center of the galaxy. The cloud, which rotates the
polarization direction and possibly eclipses a section of the jet,
represents a "missing link" between the ultradense broad-emission-line clouds closer to the center and the lower density narrow-emission-line clouds seen on kiloparsec scales.
1 Instituto de Astrofísica de
Andalucía (CSIC), Apartado 3004, Granada 18080, Spain.
2 Institute for Astrophysical Research, Boston
University, 725 Commonwealth Avenue, Boston, MA 02215, USA.
3 Astronomical Institute, St. Petersburg State
University, Bibliotechnaya Ploschad' 2, Petrodvoretz, St. Petersburg
198904, Russia.
*
To whom correspondence should be addressed. E-mail:
jlgomez{at}iaa.es
Formerly S. G. Marchenko.
