144 citations · 419 across the 18 of their papers we have counts for
4 papers · 1 filter
In the Eye of the Storm: The Third Giant X-ray Outburst of the Extreme Changing-look AGN IC 3599
D. Grupe, S. Komossa, W. Zheng +10
We report the discovery and multiwavelength follow-up observations of a giant (factor >100) X-ray outburst of the exceptional changing-look active galactic nucleus (AGN) IC 3599. T…
Extreme line profile variations in the repeating changing-look active galactic nucleus IRAS23226-3843
Wolfram Kollatschny, Dirk Grupe, Hartmut Winkler +7
IRAS23226-3843 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 obser…
Double-peaked Ca II traces a relativistic broad-line region disk in NGC 4593
M. W. Ochmann, P. M. Weilbacher, M. A. Probst +7
Double-peaked emission lines are observed in a small percentage of active galactic nuclei (AGN). These lines allow the determination of properties of the line-emitting region, know…
Changing-look NLS1 galaxies, their detection with SVOM, and the case of NGC 1566
D. W. Xu, S. Komossa, D. Grupe +15
We discuss applications of the study of the new and barely explored class of changing-look (CL) narrow-line Seyfert 1 (NLS1) galaxies and comment on their detection with the space…