MUSE Reveals a Recent Merger in the Post-starburst Host Galaxy of the TDE ASASSN-14li

Abstract

We present MUSE integral field spectroscopic observations of the host galaxy (PGC 043234) of one of the closest ($z=0.0206$, $D\simeq 90$ Mpc) and best-studied tidal disruption events (TDE), ASASSN-14li. The MUSE integral field data reveal asymmetric and filamentary structures that extend up to $\gtrsim 10$ kpc from the post-starburst host galaxy of ASASSN-14li. The structures are traced only through the strong nebular [O III] $\lambda$5007, [N II] $\lambda$6584, and H$\alpha$ emission lines. The total off nuclear [O III] $\lambda$5007 luminosity is luminosity is $4.7\times 10^{39}$ erg s${}^{-1}$ and the ionized H mass is $\sim 10^4(500/{\mathrm{n}}_{\mathrm{e}}){\mathrm{M}}_{\odot }$. Based on the BPT diagram, the nebular emission can be driven by either AGN photoionization or shock excitation, with AGN photoionization favored given the narrow intrinsic line widths. The emission line ratios and spatial distribution strongly resemble ionization nebulae around fading AGNs such as IC 2497 (Hanny's Voorwerp) and ionization "cones" around Seyfert 2 nuclei. The morphology of the emission line filaments strongly suggest that PGC 043234 is a recent merger, which likely triggered a strong starburst and AGN activity leading to the post-starburst spectral signatures and the extended nebular emission line features we see today. We briefly discuss the implications of these observations in the context of the strongly enhanced TDE rates observed in post-starburst galaxies and their connection to enhanced theoretical TDE rates produced by supermassive black-hole binaries.

Accepted for publication in ApJL

References in corpus (8)

• A Cosmological Framework for the Co-Evolution of Quasars, Supermassive Black Holes, and Elliptical Galaxies: I. Galaxy Mergers & Quasar Activity
• The MAPPINGS III Library of Fast Radiative Shock Models
• The MUSE second-generation VLT instrument
• A Continuum of H- to He-Rich Tidal Disruption Candidates With a Preference for E+A Galaxies
• UV/Optical Detections of Candidate Tidal Disruption Events by GALEX and CFHTLS
• Candidate tidal disruption events from the XMM-Newton Slew Survey
• The Long Term Evolution of ASASSN-14li
• The TDE ASASSN-14li and its host resolved at parsec scales with the EVN

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