Interacting galaxies in the IllustrisTNG simulations -- VII: The connection between the most luminous active galactic nuclei and galaxy interactions

Shoshannah Byrne-Mamahit; David R. Patton; Sara L. Ellison; Robert Bickley; Leonardo Ferreira; Maan Hani; Salvatore Quai; Scott Wilkinson

arXiv · 2402.05196

Interacting galaxies in the IllustrisTNG simulations -- VII: The connection between the most luminous active galactic nuclei and galaxy interactions

Shoshannah Byrne-Mamahit·David R. Patton·Sara L. Ellison·Robert Bickley·Leonardo Ferreira·Maan Hani·Salvatore Quai·Scott Wilkinson

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Abstract

We investigate the connection between the most luminous active galactic nuclei (AGN), galaxy pairs, and post-mergers in the IllustrisTNG simulation. We select galaxy pairs and post-mergers with a mass ratio between 1:10 $< \mu <$ 1:1 and a redshift between $0 10^{44}$ erg/s occur in $\sim $26\% of paired galaxies with a companion within 20 kpc, compared with $\sim $14\% in controls (a fractional excess of $\sim$2). The enhancement of AGN in galaxy pairs is luminosity dependent, with the highest excess (a factor of $\sim6\pm2$ at the closest separations) for AGN with $L_{\mathrm{bol}}>10^{45}$ erg/s. Additionally, pairs exhibit a modest yet statistically significant excess of luminous AGN up to $\sim$150 kpc in separation. For pairs which merge between $0 10^{45}$ erg/s, $\sim$55\% are interacting, compared with a 30\% interaction fraction in AGN with $10^{44}<L_{\mathrm{bol}}<10^{44.5}$ erg/s. Our results support a picture in which interactions play a dominant role in (but are not the sole cause of) triggering the most luminous AGN.

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Shoshannah Byrne-Mamahit, David R. Patton, Sara L. Ellison, Robert Bickley, Leonardo Ferreira, Maan Hani, Salvatore Quai, Scott Wilkinson. 2024-02-07. Interacting galaxies in the IllustrisTNG simulations -- VII: The connection between the most luminous active galactic nuclei and galaxy interactions. https://arxiv.org/abs/2402.05196

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