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arXiv · 1902.10011

Investigating the Candidate Displaced Active Galactic Nucleus in NGC 3115

Megan L. Jones·Sarah Burke-Spolaor·Kristina Nyland·Joan M. Wrobel
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Abstract

The nearby galaxy NGC 3115 contains a known radio-emitting, low-luminosity active galactic nucleus (AGN), and was recently claimed to host a candidate AGN displaced 14.3 pc from the galaxy's optical photocenter. Our goal is to understand whether this represents a single offset AGN, an AGN in orbit around a central black hole, or something else. We present a new, sensitive (RMS = 4.4 $μ$Jy beam$^{-1}$) 10 GHz image, which finds evidence for only one AGN. We place a stringent limit on the radio luminosity of any secondary supermassive black hole of $L_{10~\rm{GHz}}<5.8\times10^{33}$ ergs/s. An analysis of the relative positioning of the radio core, X-ray nucleus, and stellar bulge in this galaxy indicate that the radio source is centrally located, and not offset from the galactic bulge. This provides an argument against a single offset AGN in NGC 3115, however does not provide conclusive evidence against the purported offset AGN as an in-spiralling secondary black hole.

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Megan L. Jones, Sarah Burke-Spolaor, Kristina Nyland, Joan M. Wrobel. 2019-02-26. Investigating the Candidate Displaced Active Galactic Nucleus in NGC 3115. https://doi.org/10.3847/1538-4357%2Fab0a09

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