Mid-infrared Outbursts in Nearby Galaxies: Nuclear Obscuration and Connections to Hidden Tidal Disruption Events and Changing-look Active Galactic Nuclei

2023/07/11 by Sierra A. Dodd, Arya Nukala, Isabelle Connor +7 · 1 voice · 3 citations
Physics and Astronomy · #Astrophysical Phenomena and Observations #Galaxies: Formation, Evolution, Phenomena #Stellar, planetary, and galactic studies #astro-ph.GA

paper · pdf · doi:10.3847/2041-8213/ad1112

openalex publication_date 2023/12/01 · openalex created_date 2023/12/19 · openalex updated_date 2026/07/22

Abstract

Abstract We study the properties of galaxies hosting mid-infrared outbursts in the context of a catalog of 500,000 galaxies from the Sloan Digital Sky Survey. We find that nuclear obscuration, as inferred by the surrounding dust mass, does not correlate with host galaxy type, stellar properties (e.g., total mass and mean age), or with the extinction of the host galaxy as estimated by the Balmer decrement. This implies that nuclear obscuration may not be able to explain any overrepresentation of tidal disruption events in particular host galaxies. We identify a region in the galaxy catalog parameter space that contains all unobscured tidal disruption events but only harbors ≲11% of the mid-infrared outburst hosts. We find that mid-infrared outburst hosts appear more centrally concentrated and have higher galaxy Sérsic indices than galaxies hosting active galactic nuclei (AGNs) selected using the Baldwin–Phillips–Terlevich classification. We thus conclude that the majority of mid-infrared outbursts are not hidden tidal disruption events but are instead consistent with being obscured AGN that are highly variable, such as changing-look AGN.

Citations

• The UV‐Optical Galaxy Color‐Magnitude Diagram. III. Constraints on Evolution from the Blue to the Red Sequence
• The Coevolution of Galaxies and Supermassive Black Holes: Insights from Surveys of the Contemporary Universe
• Coevolution (Or Not) of Supermassive Black Holes and Host Galaxies
• Obscured Active Galactic Nuclei

Cited by

• Radio Variability in Recently-Quenched Galaxies: The Impact of TDE or AGN Driven Outflows
• Quantifying the Active Galactic Nuclei Fraction in Cosmic Voids via Mid-Infrared Variability
• Modeling Star Formation Histories of Changing-Look AGN Host Galaxies with Prospector

Discussions

• 🔭 Interesting paper on arxiv tonight by SAO REU alum Sierra Dodd, studying mid-IR variability of obscured AGN https://arxiv.org/abs/2307.05670 [bsky, 5 points, 0 comments]

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