Publications (31)
The intermediate-ionization lines as virial broadening estimators for Population A quasars
P. Marziani, A. del Olmo, C. A. Negrete +10
The identification of a virial broadening estimator in the quasar UV rest frame suitable for black hole mass computation at high redshift has become an important issue. We compare…
Quasar emission lines as virial luminosity estimators
P. Marziani, E. Bon, N. Bon +6
Quasars accreting matter at very high rates (known as extreme Population A [xA]) may provide a new class of distance indicators covering cosmic epochs from present day up to less t…
Highly accreting quasars: The SDSS low-redshift catalog
C. A. Negrete, D. Dultzin, P. Marziani +8
The most highly accreting quasars (xA) are of special interest in studies of the physics of AGNs and host galaxy evolution. Quasars accreting at high rates (L/LEdd 1) hold p…
Exploring possible relations between optical variability time scales and broad emission line shapes in AGN
E. Bon, P. Jovanovic, P. Marziani +2
Here we investigate the connection of broad emission line shapes and continuum light curve variability time scales of type-1 Active Galactic Nuclei (AGN). We developed a new model…
Periodic optical variability of AGN
E. Bon, P. Marziani, N. Bon
Here we present the evidence for periodicity of an optical emission detected in several AGN. Significant periodicity is found in light curves and radial velocity curves. We discuss…
A possible mechanism for multiple changing look phenomenon in Active Galactic Nuclei
M. Sniegowska, B. Czerny, E. Bon +1
Changing-look phenomenon observed now in a growing number of active galaxies challenges our understanding of the accretion process close to a black hole. We propose a simple explan…
Extreme quasars as distance indicators in cosmology
D. Dultzin, P. Marziani, J. A. de Diego +7
Quasars accreting matter at very high rates (known as extreme Population A [xA] quasars, possibly associated with super-Eddington accreting massive black holes) may provide a new c…
H II emission line region in LEDA 212995, a small neighboring galaxy of Mrk 1040
L. C. Popovic, E. G. Mediavilla, E. Bon +2
We present here new spectroscopic observations of Mrk 1040 and LEDA 212995 (Mrk 1040 companion) obtained with the Isaac Newton Telescope (INT). The intensity ratios and widths for…
Changing-look NLS1 galaxies, their detection with SVOM, and the case of NGC 1566
D. W. Xu, S. Komossa, D. Grupe +15
We discuss applications of the study of the new and barely explored class of changing-look (CL) narrow-line Seyfert 1 (NLS1) galaxies and comment on their detection with the space…
Efficiency tests for estimating the gas and stellar population parameters in Type 2 objects
N. Bon, L. C. Popovic, E. Bon
We investigated the efficiency of estimating characteristics of stellar populations (SP) and Active Galactic Nuclei (AGN) emission using ULySS code. To analyse simultaneously AGN a…
Optical spectral properties of radio loud quasars along the main sequence
A. del Olmo, P. Marziani, V. Ganci +4
We analyze the optical properties of Radio-Loud quasars along the Main Sequence (MS) of quasars. A sample of 355 quasars selected on the basis of radio detection was obtained by cr…
Selection of highly-accreting quasars: Spectral properties of FeII emitters not belonging to extreme Population A
N. Bon, P. Marziani, E. Bon +5
The quasar class of extreme Population A (xA) (also known as super-Eddington accreting massive black holes, SEAMBHs) has been hailed as potential distance indicators for cosmology.…
The Line Emission Region in III Zw 2: Kinematics and Variability
L. C. Popovic, E. G. Mediavilla, E. Bon +2
We have studied the Ly-al, Hbeta, Halpha and Mg II2798 line profiles of the Seyfert 1 galaxy III Zw 2. The shapes of these broad emission lines show evidence of a multicomponent or…
A main sequence for quasars
P. Marziani, D. Dultzin, J. W. Sulentic +7
The last 25 years saw a major step forward in the analysis of optical and UV spectroscopic data of large quasar samples. Multivariate statistical approaches have led to the definit…
The First Spectroscopically Resolved Sub-parsec Orbit of a Supermassive Binary Black Hole
E. Bon, P. JovanoviÄ, P. Marziani +6
One of the most intriguing scenarios proposed to explain how active galactic nuclei are triggered involves the existence of a supermassive binary black hole system in their cores.…
Black hole mass estimates in quasars - A comparative analysis of high- and low-ionization lines
P. Marziani, A. del Olmo, M. A. Martinez-Carballo +7
The inter-line comparison between high- and low-ionization emission lines has yielded a wealth of information on the quasar broad line region (BLR) structure and dynamics, includin…
Fe II velocity shifts in optical spectra of type 1 AGN
E. Bon, P. Marziani, M. Berton +4
Here we present a critical view of practical problems in the analysis of optical Fe II emission lines of Type 1 AGN spectra. Besides the very complex and unclear physical interpret…
Evidence for periodicity in 43 year-long monitoring of NGC 5548
E. Bon, S. Zucker, H. Netzer +14
We present an analysis of 43 years (1972 to 2015) of spectroscopic observations of the Seyfert 1 galaxy NGC 5548. This includes 12 years of new unpublished observations (2003 to 20…
Complex emission line region of Mrk 817
D. Ilic, L. C. Popovic, E. Bon +2
In this work we study the physical and kinematical properties of the emission line region of Seyfert 1.5 galaxy Mrk 817 using three sets of observations, among which are high-resol…
Evidence for a Stratified Accretion Disk Wind in AGN
P. Marziani, E. Bon, S. Panda +5
We present observational evidence supporting the presence of a stratified accretion disk wind in active galactic nuclei (AGN), based on multi-wavelength spectroscopic analysis of b…
Quasars: from the Physics of Line Formation to Cosmology
P. Marziani, E. Bon, N. Bon +6
Quasars accreting matter at very high rates (known as extreme Population A [xA] or super-Eddington accreting massive black holes) provide a new class of distance indicators coverin…
Radio-loudness along the quasar main sequence
V. Ganci, P. Marziani, M. D'Onofrio +4
Following the established view of the AGNs inner workings, an AGN is radio-loud (RL) if associated with relativistic ejections emitting a radio synchrotron spectrum (i.e., a jetted…
Complex Broad Emission Line Profiles of AGN - Geometry of the Broad Line Region
E. Bon, N. Gavrilovic, G. La Mura +1
The Broad Emission Lines (BELs) in spectra of type 1 Active Galactic Nuclei (AGN) can be very complex, indicating a complex Broad Line Region (BLR) geometry. According to the stand…
Spectroscopy and spectropolarimetry of AGN: from observations to modelling
L. C. Popovic, D. Ilic, E. Bon +10
Active galactic nuclei (AGN) are one of the most luminous objects in the Universe, emitting powerful continuum and line emission across all wavelength bands. They represent an impo…
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…
Contribution of a Disk Component to Single Peaked Broad Lines of Active Galactic Nuclei
E. Bon, L. Ä. PopoviÄ, N. GavriloviÄ +2
We study the disk emission component hidden in the single-peaked Broad Emission Lines (BELs) of Active Galactic Nuclei (AGN). We compare the observed broad lines from a sample of 9…
Contribution of the Disk Emission to the Broad Emission Lines in AGNs: Two-component model
L. C. Popovic, E. Mediavilla, E. Bon +1
We present an investigation of the structure of the emission line region in a sample of 12 single-peaked Active Galactic Nuclei (AGNs). Using the high resolution H-beta and H-alpha…
Narrow-line Seyfert 1s: what is wrong in a name?
P. Marziani, A. del Olmo, M. D' Onofrio +6
Narrow-line Seyfert 1s (NLSy1s) are an ill-defined class. Work done over the past 20 years as well as recent analyses show a continuity in properties (e.g., Balmer line profiles, b…
The Main Sequence of quasars: the taming of the extremes
P. Marziani, E. Bon, N. Bon +12
The last few years have seen the confirmation of several trends associated with the quasar main sequence. The idea of a main sequence for quasars is relatively recent, and its full…
The Disk Plus (Failed) Wind System of 3C 47: A Story of Accretion Disks and Binary Black Holes
P. Marziani, S. Terefe Mengistue, A. del Olmo +9
[Abridged] Optically thick, geometrically thin accretion disks around supermassive black holes are thought to contribute to broad-line emission in type-1 active galactic nuclei (AG…
The quasar main sequence and its potential for cosmology
P. Marziani, D. Dultzin, A. Del Olmo +10
The main sequence offers a method for the systematization of quasar spectral properties. Extreme FeII emitters (or extreme Population A, xA) are believed to be sources accreting ma…