A Wandering SMBH Eating a Star

A Wandering Supermassive Black Hole Eating a Star [@Saad2026]

Astrobites post

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• Covers a paper investigating a TDEs discovered away from the center of a galaxy, denoted as AT2024tvd.
• BH mass determines accretion disk behavior, with more massive BHs having larger, cooler disks
• This can be measured with the disks’ brightness
• This was observed with Pan-STARRS, Swift Observatory, Pan-STARRS, and XMM-Newton
• TDEs start with an initial burst in visible and UV which is not very well understood, but after a period of time (few hundred days) the visible and UV light start to come from the accretion disk
• Used a model called kerrSED, which measures spectral energy distribution (SED), this accounts for disk temp, physical size, spin, viewing angle, and Comptonization
• From this fitting they found that the BH had a mass of $\sim M_{\odot }$, classifying it as a SMBH
• This puts it in a unique spot, as previously detected TDEs were located in Ultra-Compact Dwarf Galaxies, small dense collections of stars which orbit larger host galaxies.
• AT2024tvd has nearly no surrounding stars, suggesting that it is `wandering’, having being ejected form a galaxy merger and now slowly drifting towards the galactic center, sheding stars as it goes.