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Extreme Accretion Events: TDEs and Changing-Look AGN
S. Komossa, D. Grupe
We present a review of the topics of X-ray stellar tidal disruption events (TDEs) and changing-look active galactic nuclei (AGN). Stars approaching a supermassive black hole (SMBH)…
The outburst of the changing-look AGN IRAS23226-3843 in 2019
Wolfram Kollatschny, Dirk Grupe, Michael L. Parker +8
IRAS23226-3843 has previously been classified as a changing-look AGN based on X-ray and optical spectral variations. In 2019, Swift observations revealed a strong rebrightening in…
Flares in the changing look AGN Mrk 590. I: The UV response to X-ray outbursts suggests a more complex reprocessing geometry than a standard disk
Daniel Lawther, Marianne Vestergaard, Sandra Raimundo +5
Mrk 590 is a known changing-look AGN which almost turned off in 2012, and then in 2017 partially re-ignited into a repeat flaring state, unusual for an AGN. Our \emph{Swift} observ…
Refining the prediction for OJ 287 next impact flare arrival epoch
Mauri J. Valtonen, Staszek Zola, A. Gopakumar +23
The bright blazar OJ~287 routinely parades high brightness bremsstrahlung flares which are explained as being a result of a secondary supermassive black hole (SMBH) impacting the a…
Comparing Reflection and Absorption Models for the Soft X-ray Variability in the NLS1 AGN UGC 11763
Jiachen Jiang, Luigi C. Gallo, Dirk Grupe +1
We present a spectral analysis of two XMM-Newton observations of the narrow-line Seyfert 1 galaxy UGC 11763. UGC 11763 shows very different soft X-ray spectral shapes in the two ob…
Collimation of the kiloparsec-scale radio jets in NGC 2663
Velibor Velović, M. D. Filipović, L. Barnes +25
We present the discovery of highly-collimated radio jets spanning a total of 355 kpc around the nearby elliptical galaxy NGC 2663, and the possible first detection of recollimation…