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arXiv · 2611.07533

Constraining the timescale of activity in Mrk 1018

Rebecca McElroy·Scott M. Croom·Thomas Dunn
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Abstract

We present analysis of an extended emission line region projected 3.77 kpc from the nucleus of the canonical changing-look AGN Mrk~1018, found in MUSE integral-field observations from the Close AGN Reference Survey. Emission-line ratios show that the region exhibits AGN ionisation but has a very low velocity dispersion, $77 \pm 1$ kms$^{-1}$, ruling out an ionised outflow. The lower limit on the light travel time is $12{,}300 \pm 2{,}300$ yr, implying that the nucleus has therefore been active for at least this long. This is much longer than the duration of either observed changing-look transition, which occurred over several years. This implies that Mrk 1018's multi-year variations are occurring within a longer term active phase.

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Rebecca McElroy, Scott M. Croom, Thomas Dunn. 2026-11-05. Constraining the timescale of activity in Mrk 1018. https://arxiv.org/abs/2611.07533

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