activity
20172026
most citedA possible mechanism for multiple changing look phenomenon in Active Galactic Nuclei

135 citations · 996 across the 47 of their papers we have counts for

collaborators

47 papers

astro-ph.HE2026

Radiation-hydrodynamics of star-disc collisions: From system parameters to outflows and lightcurves

Taj Jankovič, Sergey Karpov, Michal Zajaček +2

Quasi-periodic eruptions (QPEs) are nuclear transients producing bright, repeating soft X-ray flares superimposed on quiescent emission. A promising interpretation is that they are…

astro-ph.GA2026

Spatially resolved optical and mid-infrared spectroscopy of SDSS1335+0728: implications for the origin of the Ansky event

P. Sánchez-Sáez, M. Masterson, L. Hernández-García +25

The galaxy SDSS1335+0728 brightened abruptly in December 2019 (the Ansky event) and has since been confirmed as the host of extreme X-ray quasi-periodic eruptions (QPEs) of debated…

astro-ph.GA2026

Radiation Pressure Instability in the "turn-on" Changing-Look AGN SDSS J1430+2303

Han He, Bei You, Marzena Śniegowska +3

We aim to investigate the multi-wavelength variability, spectral, and timing properties of the changing-look active galactic nucleus (CL AGN) SDSS J1430+2303, and to explore the ph…

astro-ph.HE2026

Tidal disruption of a low-mass star in an active galactic nucleus as the origin of the PS16dtm outburst

Marzena Śniegowska, Bożena Czerny, Michal Zajaček +7

The event PS16dtm, which occured in the center of the Narrow Line Seyfert 1 (NLS1) galaxy SDSS J015804.75-005221.8 (z = 0.080440), is one of the few candidates for a tidal disrupti…

astro-ph.HE2025

Optical and cm follow-ups of the Changing-Look event in Mkn 590

Biswaraj Palit, Abhijeet Borkar, Agata Różańska +5

The Changing-Look active galactic nucleus Mkn 590 is currently in a rejuvenated state, exhibiting a contemporaneous flux rise across X-rays, UV, optical and cm wavelengths. In this…

astro-ph.GA2025

Feeding frenzy in the mighty black holes: what we could learn from them?

Swayamtrupta Panda, Hygor Benati Gonçalves, Thaisa Storchi-Bergmann +14

Eddington ratio is a paramount parameter governing the accretion history and life cycles of Active Galactic Nuclei (AGNs). This short review presents a multi-faceted view of the im…

astro-ph.GA2025

SDSS-V Black Hole Mapper: The Index Diagram as a tool to disentangle the influence of the Host Galaxy in Quasar spectra

C. A. Negrete, R. Sandoval-Orozco, H. Ibarra-Medel +32

We revisit the Quasar Main Sequence (QMS) by investigating the impact of the stellar component from the host galaxy (HG) on the emission line spectra of the active galactic nuclei…

astro-ph.GA2025★ 8 cited

The Nineteenth Data Release of the Sloan Digital Sky Survey

SDSS Collaboration, Gautham Adamane Pallathadka, Mojgan Aghakhanloo +210

Mapping the local and distant Universe is key to our understanding of it. For decades, the Sloan Digital Sky Survey (SDSS) has made a concerted effort to map millions of celestial…

astro-ph.HE2025

AT 2019aalc: a Bowen Fluorescence Flare With a Precursor Flare in an Active Galactic Nucleus

Marzena Śniegowska, Benny Trakhtenbrot, Lydia Makrygianni +10

AT 2019aalc is a peculiar sequence of highly variable emission events observed towards the nucleus of the broad-line AGN SDSS J152416.66+045119.0. The system exhibited two distinct…

astro-ph.HE2025

Markarian 590: The AGN Awakens

Biswaraj Palit, Marzena Śniegowska, Alex Markowitz +3

Changing-Look AGN (CLAGN) Mkn 590 recently underwent a sudden re-ignition, marked by substantial increases in optical/UV and X-ray continuum flux since last couple of years. Swift-…

astro-ph.GA2024★ 17 cited

Chemical abundances along the quasar main sequence

A. Floris, P. Marziani, S. Panda +5

The 4D eigenvector 1 (E1) sequence has emerged as a powerful tool for organizing the observational and physical characteristics of type-1 active galactic nuclei (AGNs). In this stu…

astro-ph.HE2024★ 22 cited

Alive but Barely Kicking: News from 3+ years of Swift and XMM-Newton X-ray Monitoring of Quasi-Periodic Eruptions from eRO-QPE1

Dheeraj R. Pasham, Eric R. Coughlin, Michal Zajacek +11

Quasi-periodic Eruptions (QPEs) represent a novel class of extragalactic X-ray transients that are known to repeat at roughly regular intervals of a few hours to days. Their underl…

astro-ph.HE2024★ 32 cited

Lense-Thirring Precession after a Supermassive Black Hole Disrupts a Star

Dheeraj R. Pasham, Michal Zajacek, C. J. Nixon +8

An accretion disk formed around a supermassive black hole (SMBH) after it disrupts a star is expected to be initially misaligned with respect to the black hole's equatorial plane.…

astro-ph.GA2024

From sub-solar to super-solar chemical abundances along the quasar main sequence

Paola Marziani, Alberto Floris, Alice Deconto-Machado +8

The 4D Eigenvector 1 sequence has proven to be a highly effective tool for organizing observational and physical properties of type 1 active galactic nuclei (AGN). In this paper, w…

astro-ph.GA2024★ 50 cited

Exploring Changing-look Active Galactic Nuclei with the Sloan Digital Sky Survey V: First Year Results

Grisha Zeltyn, Benny Trakhtenbrot, Michael Eracleous +32

"Changing-look" active galactic nuclei (CL-AGNs) challenge our basic ideas about the physics of accretion flows and circumnuclear gas around supermassive black holes. Using first-y…

astro-ph.GA2023

Accretion processes onto black holes: theoretical problems, observational constraints

Bozena Czerny, Marzena Sniegowska, Agnieszka Janiuk +1

We shortly summarize the standard current knowledge on the structure of the accretion flow onto black holes in galactic binary systems and in active galactic nuclei. We stress the…

astro-ph.GA2023★ 12 cited

Broad-line region in active galactic nuclei: Dusty or dustless?

Ashwani Pandey, Bozena Czerny, Swayamtrupta Panda +5

Context. Dust in active galactic nuclei is clearly present right outside the broad-line region (BLR) in the form of a dusty molecular torus. However, some models of the BLR predict…

astro-ph.GA2023★ 9 cited

UV Fe II emission model of HE 0413-4031 and its relation to broad-line time delays

Michal Zajaček, Swayamtrupta Panda, Ashwani Pandey +11

Fe II emission is a well-known contributor to the UV spectra of active galactic nuclei and the modeling of this part may affect the results obtained for the MgII emiss…

astro-ph.GA2023

BAL effect in quasars due to source orientation

M. Sniegowska, M. H. Naddaf, M. L. Martinez-Aldama +3

We investigated a scenario where the presence of a broad absorption line (BAL) feature in quasars (QSOs) is contingent upon the line of sight being situated within an outflow cone…

astro-ph.HE2023★ 2 cited

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…

astro-ph.GA2023★ 13 cited

Wavelength-resolved reverberation mapping of intermediate redshift quasars HE 0413-4031 and HE 0435-4312: Dissecting Mg II, optical Fe II, and UV Fe II emission regions

Raj Prince, Michal Zajaček, S. Panda +24

We present the wavelength-resolved reverberation mapping (RM) of combined MgII and UV FeII broad-line emissions for two intermediate redshifts (z1), luminous quasars - HE 041…

astro-ph.GA2022★ 19 cited

Dust-driven wind as a model of Broad Absorption Line quasars

Mohammad Hassan Naddaf, Mary Loli Martinez-Aldama, Paola Marziani +3

We test a scenario claiming that the broad absorption line (BAL) phenomenon in quasars (QSOs) is not a temporary stage of their life. In this scenario, we see the BAL effect only i…

astro-ph.GA2022★ 13 cited

Dusty plasma in active galactic nuclei

Bożena Czerny, Michal Zajaček, Mohammad-Hassan Naddaf +10

Since many years we know that dust in the form of the dusty-molecular torus is responsible for the obscuration in active galactic nuclei (AGN) at large viewing angles and thus for…

astro-ph.GA2022★ 22 cited

Accretion disks, quasars and cosmology: meandering towards understanding

Bozena Czerny, Shulei Cao, Vikram Kumar Jaiswal +11

As Setti & Woltjer noted back in 1973, quasars could be used to construct the Hubble diagram but the actual application was not that straightforward. It took years to implement the…