SIMBAD references

2026A&A...707A..46K - Astronomy and Astrophysics, volume 707A46 (2026/3-1)

Extreme line profile variations in the repeating changing-look active galactic nucleus IRAS 23226-3843.

KOLLATSCHNY W., GRUPE D., WINKLER H., PROBST M.A., OCHMANN M.W., PONITZSCH A., SCHARTEL N., WOLSING S., KOMOSSA S. and POTTER S.B.

Abstract (from CDS):

Aims. IRAS 23226-3843 has been identified as a highly variable Seyfert galaxy and even as a changing-look active galactic nucleus based on optical spectra. Here we present follow-up observations - taken over the past five years - for examining the ongoing photometric and spectral variations in this remarkable galaxy.
Methods. We carried out Swift observations of IRAS 23226-3843 together with new optical spectra taken in 2023 and 2024. In parallel we investigate ASAS-SN photometric data from 2014 till 2025.
Results. IRAS 23226-3843 stayed on a high continuum flux level in the X-ray as well as in the optical since a historic outburst in 2019. However, it shows strong short-term variations on timescales of a few months. Densely sampled ASAS-SN V-band continuum data from 2014 till 2025 confirm that behavior. IRAS 23226-3843 switched from a clear Seyfert 1 type in December 2019 to a Seyfert 1.9/2 type in July 2020 based on its optical spectra. Afterward, it again became a Seyfert 1 type with symmetric broad single-peaked Balmer line profiles in January 2023. These spectra prove the repeating changing-look character of the galaxy. IRAS 23226-3843 exhibits extreme high Balmer decrements Hα/Hβ based on their broad line components. The Balmer decrement values are on the order of 10. IRAS 23226-3843 successively showed all types of broad line Balmer profiles during the past 25 years over periods of many years: asymmetric single-peaked, double-peaked, as well as single-peaked and symmetric profiles in addition to its Seyfert 1.9/2 transition. These variations are not clearly correlated with continuum and line intensity variations.

Abstract Copyright: © The Authors 2026

Journal keyword(s): galaxies: active - galaxies: individual: IRAS23226-3843 - galaxies: nuclei - quasars: emission lines - galaxies: Seyfert - X-rays: galaxies

Simbad objects: 19

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