Megaparsec-scale Radio Structure Associated with a Hybrid Blazar SBS B1646+499: Episodic Jet Activity with Precessing Axis
Abstract
Here we report on the total-intensity 610 MHz Giant Meterwave Radio Telescope (GMRT) observations of the peculiar hybrid blazar SBS B1646+499, which merges the properties of BL Lacertae objects and flat-spectrum radio quasars. The complex radio structure of SBS B1646+499, emerging from the archival radio data and our new GMRT observations, consists of the megaparsec-scale elongated halo, the unilateral kiloparsec-scale jet, and the nuclear jet extending up to ∼20 pc from the compact core. The giant halo is characterized by a steep radio spectrum, indicative of the advanced aging of the electron population within the lobes. For the large-scale jet, we detected a spectral gradient along and across the outflow, and in particular spectral flattening of the radio continuum toward the jet edges, suggestive of the spine-boundary shear layer morphology. The nuclear jet displays superluminal knots emerging from the self-absorbed and variable radio core. We interpret all these findings in the framework of the model of an episodic jet activity with a precessing jet axis.
- Publication:
-
The Astrophysical Journal
- Pub Date:
- November 2018
- DOI:
- 10.3847/1538-4357/aae1a9
- arXiv:
- arXiv:1809.04867
- Bibcode:
- 2018ApJ...868...64P
- Keywords:
-
- accretion;
- accretion disks;
- BL Lacertae objects: individual: SBS B1646+499;
- galaxies: active;
- galaxies: jets;
- radiation mechanisms: non-thermal;
- radio continuum: galaxies;
- Astrophysics - High Energy Astrophysical Phenomena
- E-Print:
- 10 pages, 5 figures