119 citations · 165 across the 14 of their papers we have counts for
14 papers
Radio Properties of Narrow-Line and Broad-Line Seyfert 1 Galaxies
K. É. Gabányi, S. Komossa, A. Mezősi +2
Narrow-line Seyfert 1 (NLS1) galaxies host active galactic nuclei (AGN) with narrow optical emission lines of the broad-line region. This is often explained with a relatively lower…
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…
Dual AGN and Multiple SMBH Systems in the Era of SKAO
Q. D'Amato, L. Cui, R. Deane +23
We present a radio-oriented review of current strategies for the detection and characterization of dual active galactic nuclei (DAGN) and supermassive black hole binaries (SMBHBs),…
Exploring Tidal Disruption Events with SKA and VLBI: Unveiling the Mystery of Black Hole Feeding and Outflows
Xinwen Shu, Guobin Mou, Tao An +8
Tidal disruption events (TDEs) probe the birth and evolution of black hole accretion flows and jets on human timescales. Radio emission traces shocks and outflows from thermal TDEs…
SDSSJ110546.07+145202.4: The first long-duration radio changing-look NLS1 galaxy
S. Komossa, D. Grupe, A. Kraus +12
SDSSJ110546.07+145202.4 stands out as a unique radio changing-look Narrow-line Seyfert 1 (NLS1) galaxy that has brightened dramatically and shows an exceptionally long duration of…
Very Long Baseline Interferometry Search for Nuclear Radio Continuum Emission in the Barred Spiral Galaxy NGC 7479
Seppo Laine, Emmanuel Momjian, Emilia Järvelä +4
We have obtained very high angular resolution (a few milliarcseconds or sub-parsec scale) Very Long Baseline Array (VLBA) and European Very Long Baseline Interferometry (VLBI) Netw…
Are "Changing-Look" Active Galactic Nuclei Special in the Coevolution of Supermassive Black Holes and their Hosts? II. The Case of Changing-Look Narrow-Line Seyfert 1 Galaxies
J. Wang, S. Jin, D. W. Xu +5
The evolutionary role of the so-called ``changing-look'' (CL) active galactic nucleus (AGN), which is characterized by spectral-type transitions within yr, has been sugges…
SVOM discovery of a strong X-ray outburst of the blazar 1ES~1959+650 and multi-wavelength follow-up with the Neil Gehrels Swift observatory
A. Foisseau, A. Coleiro, S. Komossa +37
On December 6, 2024, 1ES 1959+650, one of the X-ray brightest blazars known, underwent a high-amplitude X-ray outburst detected by SVOM, the first such discovery with this mission.…
The Multi-Wavelength Context of Delayed Radio Emission in TDEs: Evidence for Accretion-Driven Outflows
Kate D. Alexander, Raffaella Margutti, Sebastian Gomez +20
Recent observations presented in Cendes et al. (2024a) show that optically selected tidal disruption events (TDEs) commonly produce delayed radio emission that can peak years post-…
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…
The extremes of AGN variability: outbursts, deep fades, changing looks, exceptional spectral states, and semi-periodicities
S. Komossa, D. Grupe, P. Marziani +16
The extremes of Active Galactic Nuclei (AGN) variability offer valuable new insights into the drivers and physics of AGN. We discuss some of the most extreme cases of AGN variabili…
On R-W1 as A Diagnostic to Discover Obscured Active Galactic Nuclei in Wide-Area X-ray Surveys
Stephanie M. LaMassa, Francesca Civano, Marcella Brusa +18
Capitalizing on the all-sky coverage of {\it WISE}, and the 35\% and 50\% sky coverage from SDSS and Pan-STARRS, respectively, we explore the efficacy of (optical) - $m_{3.…
A milliparsec supermassive black hole binary candidate in the galaxy SDSS J120136.02+300305.5
F. K. Liu, Shuo Li, S. Komossa
Galaxy mergers play a key role in the evolution of galaxies and the growth of their central supermassive black holes (SMBHs). A search for (active) SMBH binaries (SMBHBs) at the ce…
The XMM-Newton spectrum of a candidate recoiling supermassive black hole: an elusive inverted P-Cygni profile
G. Lanzuisi, F. Civano, S. Marchesi +12
We present a detailed spectral analysis of new XMM-Newton data of the source CXOC J100043.1+020637, also known as CID-42, detected in the COSMOS survey at z = 0.359. Previous works…