Possible jet reorientation in low-frequency radio structures of blazars
Abstract
Blazars are active galactic nuclei (AGNs) observed at small viewing angles to the observer’s line of sight; hence most of them are compact sources in the radio regime. At low radio frequencies, we may observe additional extended structures, considered to be lobes propagating directly towards Earth. However, there are rare cases of blazars whose morphologies are interpreted in the framework of an episodic jet activity with a reorientation of the jet axis. In this paper, we aim to find other candidates for sources of this kind and present Low Frequency Array (LOFAR) observations of seven blazars with rare morphologies composed of kiloparsec-scale jets and elongated multihundred kiloparsec-scale features. Based on their radio images and physical parameters, we propose that jets could change the direction of propagation out of the sky plane during the lifetime of at least some of these sources and with such we may observe morphologically different AGN types simultaneously, similar to the previously discovered blazar SBS B1646+499. Several plausible origin scenarios are presented, including fast realignment and precession. We also derive the 144 MHz fluxes of the compact and extended structures, the total radio luminosities, the spectral indices for the diffuse haloes, and the core-dominance parameters. We also discuss the possibility that these objects are actually giant blazars with rare Fanaroff–Riley I (FR I) morphology. The previously discovered blazar SBS B1646+499 should be classified as a giant independently of its inclination with regard to the observer.
Document Details
- Document Type
- Pub Defense Publication
- Publication Date
- Jun 16, 2022
- Source ID
- 10.1093/mnras/stac1372
Entities
People
- Bartosz Śmierciak
- Marek Jamrozy
- Urszula Pajdosz-Śmierciak
Organizations
- Alfred P. Sloan Foundation
- American Museum of Natural History
- California Institute of Technology
- Case Western Reserve University
- Chinese Academy of Sciences
- Drexel University
- Higher Education Funding Council for England
- Jagiellonian University
- Jet Propulsion Laboratory
- Johns Hopkins University
- Los Alamos National Laboratory
- Max Planck Society
- Ministry of Science and Higher Education
- National Aeronautics and Space Administration
- National Science Foundation
- New Mexico State University
- Ohio State University
- Princeton University
- Science Foundation Ireland
- United States Naval Observatory
- University of Basel
- University of Chicago
- University of Pittsburgh
- University of Portsmouth
- University of Washington