23 citations · 124 across the 25 of their papers we have counts for
6 papers · 1 filter
A large population of over-massive black hole quasars at z=0.3-0.8 revealed by eROSITA
Johannes Buchner, Isabelle Gauger, Qiaoya Wu +14
In most galaxies, the central black hole accounts for no more than a percent of the total mass in stars. Recently, however, extremely over-massive black holes with ratios of 10% ha…
Characterising the X-ray variability of QSOs to the highest Eddington ratios and black hole masses with eROSITA light curves
Antonis Georgakakis, Angel Ruiz, Johannes Buchner +9
An important diagnostic of the inner structure of accretion flows onto supermassive black holes are the stochastic flux variations at X-ray wavelengths. Despite its significance, a…
The Average Soft X-ray Spectra of eROSITA Active Galactic Nuclei
Shi-Jiang Chen, Johannes Buchner, Teng Liu +16
Context. AGNs are strong X-ray emitters shaped by disk-corona interactions. The soft excess (0.5-2.0 keV) reveals key information about the "warm corona" bridging the disk and hot…
The eROSITA Final Equatorial Depth Survey (eFEDS): SDSS spectroscopic observations of X-ray sources
Catarina Aydar, Andrea Merloni, Tom Dwelly +45
We present one of the largest uniform optical spectroscopic surveys of X-ray selected sources to date that were observed as a pilot study for the Black Hole Mapper (BHM) survey. Th…
Searching for supermassive black holes binaries within SRG/eROSITA-De I: Properties of the X-ray selected candidates
D. Tubín-Arenas, M. Krumpe, D. Homan +20
Abridged: Supermassive black hole binaries (SMBHBs) separated by (sub)-pc scales represent one of the latest stages of hierarchical galaxy assembly. However, many of these objects…
Systematic Collapse of the Accretion Disc Across the Supermassive Black Hole Population
Scott Hagen, Chris Done, John D. Silverman +7
The structure of the accretion flow onto supermassive black holes (SMBH) is not well understood. Standard disc models match to zeroth order in predicting substantial energy dissipa…