An Amusing Look at the Host of the Periodic Nuclear Transient ASASSN-14ko Reveals a Second AGN

M. A. Tucker; B. J. Shappee; J. T. Hinkle; J. M. M. Neustadt; M. Eracleous; C. S. Kochanek; J. L. Prieto; A. V. Payne; L. Galbany; J. P. Anderson; K. Auchettl; C. Auge; Thomas W. -S. Holoien

doi:10.1093/mnras/stab2085

arXiv · 2011.05998

An Amusing Look at the Host of the Periodic Nuclear Transient ASASSN-14ko Reveals a Second AGN

M. A. Tucker·B. J. Shappee·J. T. Hinkle·J. M. M. Neustadt·M. Eracleous·C. S. Kochanek·J. L. Prieto·A. V. Payne·L. Galbany·J. P. Anderson·K. Auchettl·C. Auge·Thomas W. -S. Holoien

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Abstract

We present Multi-Unit Spectroscopic Explorer (MUSE) integral-field spectroscopy of ESO 253$-$G003, which hosts a known Active Galactic Nucleus (AGN) and the periodic nuclear transient ASASSN-14ko, observed as part of the All-weather MUse Supernova Integral-field of Nearby Galaxies (AMUSING) survey. The MUSE observations reveal that the inner region hosts two AGN separated by $1.4\pm0.1~\rm{kpc}$ ($\approx 1.\!\!^{\prime\prime}7$). The brighter nucleus has asymmetric broad, permitted emission-line profiles and is associated with the archival AGN designation. The fainter nucleus does not have a broad emission-line component but exhibits other AGN characteristics, including $v_{\rm{FWHM}}\approx 700~\rm{km}~\rm{s}^{-1}$ forbidden line emission, $\log_{10}(\rm{[OIII]}/\rm{H}\beta) \approx 1.1$, and high excitation potential emission lines such as [Fe$~$VII]$~\lambda6086$ and He$~$II$~\lambda4686$. The host galaxy exhibits a disturbed morphology with large kpc-scale tidal features, potential outflows from both nuclei, and a likely superbubble. A circular relativistic disk model cannot reproduce the asymmetric broad emission-line profiles in the brighter nucleus, but two non-axisymmetric disk models provide good fits to the broad emission-line profiles: an elliptical disk model and a circular disk + spiral arm model. Implications for the periodic nuclear transient ASASSN-14ko are discussed.

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M. A. Tucker, B. J. Shappee, J. T. Hinkle, J. M. M. Neustadt, M. Eracleous, C. S. Kochanek, J. L. Prieto, A. V. Payne, L. Galbany, J. P. Anderson, K. Auchettl, C. Auge, Thomas W. -S. Holoien. 2020-11-11. An Amusing Look at the Host of the Periodic Nuclear Transient ASASSN-14ko Reveals a Second AGN. https://doi.org/10.1093/mnras/stab2085

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