The Intriguing Parsec-Scale Radio Structure in the "Offset AGN" KISSR 102

Abstract

We report the detection of an intriguing parsec-scale radio source in the "offset AGN" candidate, KISSR 102. The elliptical host galaxy includes two optical nuclei at a projected separation of 1.54 kpc, N1 and N2, to the south-east and north-west, respectively. Phase-referenced VLBA observations at 1.5 and 4.9 GHz of this LINER galaxy, have detected double radio components (A and B) at a projected separation of 4.8 parsec at 1.5 GHz, and another partially-resolved double radio structure at 4.9 GHz coincident with the brighter radio component A. These radio detections are confined to the optical nucleus N1. The brightness temperatures of all the detected radio components are high, $\gtrsim 10^8$ K, consistent with them being components of a radio AGN. The 1.5-4.9 GHz spectral index is inverted ($\alpha \sim +0.64\pm 0.08$) for component A and steep for component B ($\alpha \lesssim -1.6$). The dramatic change in the spectral indices of A and B is inconsistent with it being a typical "core-jet" structure from a single AGN or the mini-lobes of a compact symmetric object. To be consistent with a "core-jet" structure, the jet in KISSR 102 would need to be undergoing strong jet-medium interaction with dense surrounding media resulting in a drastic spectral steepening of the jet. Alternatively, the results could be consistent with the presence of a parsec-scale binary radio AGN, which is the end result of a three-body interaction involving three supermassive black holes in the centre of KISSR 102.

11 pages, 6 figures, ApJ accepted

References in corpus (15)

• Improving the full spectrum fitting method: accurate convolution with Gauss-Hermite functions
• The MAPPINGS III Library of Fast Radiative Shock Models
• Large Merger Recoils and Spin Flips From Generic Black-Hole Binaries
• The effect of galaxy mass ratio on merger--driven starbursts
• Ejection of Supermassive Black Holes from Galaxy Cores
• Dynamics of triple black hole systems in hierarchically merging massive galaxies
• A close-pair binary in a distant triple supermassive black-hole system
• Recoiling black holes: electromagnetic signatures, candidates, and astrophysical implications
• Effects of gravitational-wave recoil on the dynamics and growth of supermassive black holes
• Offset Active Galactic Nuclei as Tracers of Galaxy Mergers and Supermassive Black Hole Growth
• Recoiling Supermassive Black Holes: a search in the Nearby Universe
• SDSS J1130+0058 an X-shaped Radio Source With Double-Peaked Low-Ionization Emission Lines: A binary Black Hole System?
• VLBI Imaging of the Double Peaked Emission Line Seyfert KISSR1494
• A Curved 150 Parsec Long Jet in the Double-Peaked Emission-Line AGN KISSR 434
• Double-Peaked Emission Lines due to A Radio Outflow in KISSR1219

Cited by in corpus (3)

• Double-peaked Lines, Dual VLBI Components, and Precessing Jets in J1328+2751
• High-Resolution Radio Observations of Five Optically Selected Type 2 Quasars
• The Nature of Jets in Double-Peaked Emission Line AGN in the KISSR Sample