426 citations · 3.7k across the 70 of their papers we have counts for
36 papers · 1 filter
Discovery of the luminous X-ray ignition eRASSt J234402.9352640; I. Tidal disruption event or a rapid increase in accretion in an active galactic nucleus?
D. Homan, M. Krumpe, A. Markowitz +17
In November 2020, a new, bright object, eRASSt J234402.9352640, was discovered in the second all-sky survey of SRG/eROSITA. The object brightened by a factor of at least 150 in…
Deciphering the extreme X-ray variability of the nuclear transient eRASSt J045650.3-203750: A likely repeating partial tidal disruption event
Zhu Liu, A. Malyali, M. Krumpe +17
(Abridged) In this paper, we present the results of an exceptional repeating X-ray nuclear transient, eRASSt J045650.3-203750 (hereafter J0456-20), uncovered by SRG/eROSITA in a qu…
Rapid X-ray Variability in Mkn 421 during a Multiwavelength Campaign
Alex G. Markowitz, Krzysztof Nalewajko, Gopal Bhatta +47
The study of short-term variability properties in AGN jets has the potential to shed light on their particle acceleration and emission mechanisms. We report results from a four-day…
High-density disc reflection spectroscopy of low-mass active galactic nuclei
L. Mallick, A. C. Fabian, J. A. García +13
The standard alpha-disc model predicts an anti-correlation between the density of the inner accretion disc and the black hole mass times square of the accretion rate, as seen in hi…
Inferring the morphology of AGN torus using X-ray spectra: A reliability study
Tathagata Saha, Alex G. Markowitz, Johannes Buchner
Numerous X-ray spectral models have been developed to model emission reprocessed by the torus of an active galactic nucleus (AGN), e.g., UXCLUMPY, CTORUS, and MYTORUS. They span a…
Detection of periodic signals in AGN red noise light curves: empirical tests on the Auto-Correlation Function and Phase Dispersion Minimization
S. Krishnan, A. G. Markowitz, A. Schwarzenberg-Czerny +1
Active galactic nucleus (AGN) emission is dominated by stochastic, aperiodic variability which overwhelms any periodic/quasi-periodic signal (QPO) if one is present. The Auto Corre…