271 citations · 4.6k across the 192 of their papers we have counts for
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A magnetically-supported disk-corona model for Changing-Look AGN transitions
Marios Kouzis, Agata Różańska, Debora Lančová +2
Changing-Look Active Galactic Nuclei (CLAGN) undergo dramatic spectral and luminosity transitions on timescales of months to a few years -- orders of magnitude shorter than the vis…
Radiation pressure instability: from heart-beat states in black hole binary systems to Quasars and Changing-Look AGN
Agnieszka Janiuk, Bozena Czerny, Pulkit Ojha +2
Radiation-pressure instability was identified soon after the seminal classical accretion disk models of Shakura-Sunyaev and Novikov-Thorne, yet its full implications remain an acti…
Unveiling Energy Pathways in AGN Accretion Flows with the Warm Corona Model for the Soft Excess
D. R. Ballantyne, V. Sudhakar, D. Fairfax +9
The soft excess in active galactic nuclei (AGNs) may arise through a combination of relativistic reflection and the effects of a warm corona at the surface of the accretion disc. D…
Observations of a black hole X-ray binary indicate formation of a magnetically arrested disk
Bei You, Xinwu Cao, Zhen Yan +8
Accretion of material onto a black hole drags any magnetic fields present inwards, increasing their strength. Theory predicts that sufficiently strong magnetic fields can halt the…
Science with a small two-band UV-photometry mission III: Active Galactic Nuclei and nuclear transients
M. Zajaček, B. Czerny, V. K. Jaiswal +14
In this review (the third in the series focused on a small two-band UV-photometry mission), we assess possibilities for a small UV two-band photometry mission in studying accreting…
Spectral Energy Distribution profiles from AGN accretion disc in multi-gap setup
Marcel Štolc, Michal Zajaček, Bożena Czerny +1
Spectral Energy Distribution (SED) of the broad-band continuum emission from black-hole accretion discs can serve as a tool to measure parameters of the central body and constrain…
Dissecting the broadband emission from γ-ray blazar PKS 0735+178 in search of neutrinos
Raj Prince, Saikat Das, Nayantara Gupta +2
The origin of the diffuse flux of TeV-PeV astrophysical neutrinos is still unknown. The -ray blazar PKS 0735+178, located outside the 90\% localization region at 2.2 deg from th…
Multiwavelength temporal and spectral study of TeV blazar 1ES 1727+502 during 2014 to 2021
Raj Prince, Rukaiya Khatoon, Pratik Majumdar +2
One of the most important questions in blazar physics is the origin of broadband emission and fast-flux variation. In this work, we studied the broadband temporal and spectral prop…
Modified models of radiation pressure instability in application to 10, 10, and 10 accreting black holes
Marzena Śniegowska, Mikołaj Grzędzielski, Bożena Czerny +1
Some of the accreting black holes exhibit much stronger variability patterns than the usual stochastic variations. Radiation pressure instability is one of the proposed mechanisms…
Non-thermal emission from fall-back clouds in the Broad-Line Region of Active Galactic Nuclei
Ana Laura Müller, Mohammad-Hassan Naddaf, Michal Zajaček +3
The spectra of active galactic nuclei exhibit broad-emission lines that presumably originate in the Broad-Line Region (BLR) with gaseous-dusty clouds in a predominantly Keplerian m…
Modeling changing-look (CL) AGN phenomenon in 1D using accretion disk instabilities
Marzena Sniegowska, Mikolaj Grzedzielski, Bozena Czerny +1
Apart from regular, low-level stochastic variability, some AGN occasionally show exceptionally large changes in the luminosity, spectral shape, and/or X-ray absorption. The most no…
Multi-wavelength Analysis and Modeling of OJ 287 During 2017-2020
Raj Prince, Aditi Agarwal, Nayantara Gupta +4
Context. The blazar OJ 287 has been proposed as a binary black hole system based on its periodic optical outburst. Among blazars with parsec scale jets, the black hole binary syste…
A comprehensive study of 2019-2020 flare of OJ 287 using AstroSat, Swift, and NuSTAR
Raj Prince, Gayathri Raman, Rukaiya Khatoon +5
OJ 287 is a well-studied binary black hole system, that occasionally exhibits bright X-ray and optical flares. Here we present a detailed spectral study of its second brightest X-r…
Insight-HXMT observations of jet-like corona in a black hole X-ray binary MAXI J1820+070
Bei You, Yuoli Tuo, Chengzhe Li +123
A black hole X-ray binary produces hard X-ray radiation from its corona and disk when the accreting matter heats up. During an outburst, the disk and corona co-evolves with each ot…
Depletion of bright red giants in the Galactic center during its active phases
Michal Zajaček, Anabella Araudo, Vladimír Karas +2
Observations in the near-infrared domain showed the presence of the flat core of bright late-type stars inside from the Galactic center supermassive black hole…
Clumpy wind accretion in Cygnus X-1
Ishika Palit, Agnieszka Janiuk, Bozena Czerny
Cygnus X-1 is one of the brightest X-ray sources observed and shows the X-ray intensity variations on time scales from milliseconds to months in both the soft and hard X-rays. The…
High metal content of highly accreting quasars
Marzena Śniegowska, Paola Marziani, Bożena Czerny +4
We present an analysis of UV spectra of 13 quasars believed to belong to extreme Population A (xA) quasars, aimed at the estimation of the chemical abundances of the broad line emi…
Radiation spectra of warm and optically thick coronae in AGN
P. -O. Petrucci, D. Gronkiewicz, A. Rozanska +9
A soft X-ray excess above the 2-10 keV power law extrapolation is generally observed in AGN X-ray spectra. Presently there are two competitive models to explain it: blurred ionized…
FeII emission in NLS1s -- originating from denser regions with higher abundances?
Swayamtrupta Panda, Paola Marziani, Bożena Czerny
The interpretation of the main sequence of quasars has become a frontier subject in the last years. The consider the effect of a highly flattened, axially symmetric geometry for th…
FeII strength in NLS1s -- dependence on the viewing angle and FWHM
Swayamtrupta Panda, Paola Marziani, Bożena Czerny
We address the effect of orientation of the accretion disk plane and the geometry of the broad-line region (BLR) in the context of understanding the distribution of quasars along t…
R-L Relation in Realistic FRADO Model
Mohammad-Hassan Naddaf, Bozena Czerny, Ryszard Szczerba
In Failed Radiatively Accelerated Dusty Outflow (FRADO) model which provides the source of material above the accretion disk (AD) as an option to explain the formation mechanism of…
Generating AGN spectra for LSST: First steps
Swayamtrupta Panda, Bożena Czerny
In the near future, the arrival of new surveys promises a significant increment in the number of quasars (QSO) at large redshift ranges. This will help to constrain the dark energy…
Main trends of the quasar main sequence -- effect of viewing angle
Swayamtrupta Panda, Paola Marziani, Bożena Czerny
We address the effect of the viewing angle of the accretion disk plane and the geometry of the broad-line region (BLR) with the goal of interpreting the distribution of quasars alo…
The Quasar Main Sequence explained by the combination of Eddington ratio, metallicity and orientation
Swayamtrupta Panda, Paola Marziani, Bożena Czerny
We address the effect of orientation of the accretion disk plane and the geometry of the broad-line region (BLR) as part of an effort to understand the distribution of quasars in t…