STScI Preprint #1321

HST and VLA Observations of Two Optical Continuum Knots in the Jet of 3C380

We present HST/WFPC2 broadband red and linear ramp filter (isolating redshifted [OII]3727Å) observations and subarcsecond resolution 15, 22 and 43 GHz VLA observations of the radio-loud quasar 3C380. We confirm the report of De Vries et al. that there is good correspondence between the locations of two optical and radio knots/hotspots in the jet. We show that the optical knots are continuum rather than line emission. The radio-optical spectrum can be fit either by a normal radio spectrum ( ~ -0.8) with a break somewhere in the infrared, or by a steeper single power-law ( ~ -1.0) (where S_ ^). We suggest that the two knots are radiating optical synchrotron emission. This would make the knots of 3C380 the most luminous optical knots/hotspots currently known.

Status:

Appeared in: The Astronomical Journal

Affiliations:

¹Space Telescope Science Institute
²Also at Kapteyn Astronomical Institute, University of Groningen