Publications (52)
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…
VAMOS: a Pathfinder for the HAWC Gamma-Ray Observatory
A. U. Abeysekara, R. Alfaro, C. Alvarez +133
VAMOS was a prototype detector built in 2011 at an altitude of 4100m a.s.l. in the state of Puebla, Mexico. The aim of VAMOS was to finalize the design, construction techniques and…
Activity induced by Gravitational Interaction in Galaxy Pairs
D. Dultzin, J. J. Gonzalez, Y. Krongold +6
A systematic study of the nuclear emission of a sample of 97 spirals in isolated galaxy pairs with mixed morphology (E+S) shows that: 1) AGN activity is found in 40% of the spiral…
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…
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…
On the LINER nuclear obscuration, Compton-thickness and the existence of the dusty torus; Clues from Spitzer/IRS spectra
O. Gonzalez-Martin, J. Masegosa, I. Marquez +7
Most of the optically classified low ionisation narrow emission-line regions (LINERs) nuclei host an active galactic nuclei (AGN). However, how they fit into the unified model (UM)…
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…
Hints on the gradual re-sizing of the torus in AGN by decomposing IRS/Spitzer spectra
O. González-MartÃn, J. Masegosa, A. Hernán-Caballero +12
Several authors have claimed that the less luminous active galactic nuclei (AGN) are not capable of sustaining the dusty torus structure. Thus, a gradual re-sizing of the torus is…
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…
Quasar massive ionized outflows traced by CIV λ1549 and [OIII]λλ4959,5007
P. Marziani, C. A. Negrete, D. Dultzin +4
The most luminous quasars (with bolometric luminosities are 1E47 erg/s) show a high prevalence of CIV λ1549 and [OIII]λλ4959,5007 emission line profiles with strong blueshifts.…
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…
What does Civλ1549 tell us about the physical driver of the Eigenvector Quasar Sequence?
J. W. Sulentic, A. del Olmo, P. Marziani +8
Broad emission lines in quasars enable us to "resolve" structure and kinematics of the broad line emitting region (BLR) thought to in- volve an accretion disk feeding a supermassiv…
LBT IR observations of candidate super-Eddington quasars
T. M. Buendia-Rios, P. Marziani, C. A. Negrete +1
Quasars accreting at very high rates are believed to be prime movers of galactic evolution because of their high radiative and mechanical output. The study presented in this paper…
Spectral optical monitoring of a double-peaked emission line AGN Arp 102B: I. Variability of spectral lines and continuum
A. I. Shapovalova, L. C. Popovic, A. N. Burenkov +14
Here we present results of the long-term (1987-2010) optical spectral monitoring of the broad line radio galaxy Arp 102B, a prototype of active galactic nuclei with the double-peak…
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.…
A new method to obtain the Broad Line Region size of high redshift quasars
C. A. Negrete, D. Dultzin, P. Marziani +1
We present high S/N UV spectra for eight quasars at z 3 obtained with VLT/FORS. The spectra enable us to analyze in detail the strong and weak emission features in the rest-…
The Activity of the Neighbours of AGN and Starburst Galaxies: Towards an evolutionary sequence of AGN activity
E. Koulouridis, M. Plionis, V. Chavushyan +4
We present a follow-up study of a series of papers concerning the role of close interactions as a possible triggering mechanism of the activity of AGN and starburst (SB) galaxies.…
Exploring the mid-infrared SEDs of six AGN dusty torus models I: synthetic spectra
O. González-MartÃn, J. Masegosa, I. GarcÃa-Bernete +9
At distances from the active galaxy nucleus (AGN) where the ambient temperature falls below ~1500-1800 K, dust is able to survive. It is thus possible to have a large dusty structu…
AGILE detection of a rapid gamma-ray flare from the blazar PKS 1510-089 during the GASP-WEBT monitoring
F. D'Ammando, G. Pucella, C. M. Raiteri +103
We report the detection by the AGILE satellite of a rapid gamma-ray flare from the powerful gamma-ray quasar PKS 1510-089, during a pointing centered on the Galactic Center region…
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…
Fifty Years of Quasars: Physical Insights and Potential for Cosmology
J. W. Sulentic, P. Marziani, D. Dultzin +2
Last year (2013) was more or less the 50th anniversary of the discovery of quasars. It is an interesting time to review what we know (and don't know) about them both empirically an…
Statistical analysis of AlIII 1860 and CIII] 1909 emission lines as virial black hole mass estimators in quasars
T. M. Buendia-Rios, C. A. Negrete, P. Marziani +1
We test the usefulness of the intermediate ionisation lines AlIII 1860 and CIII] 1909 as reliable virial mass estimators for quasars. We identify a sample of 309 quasars from the S…
Exploring the mid-infrared SEDs of six AGN dusty torus models II: the data
O. González-MartÃn, J. Masegosa, I. GarcÃa-Bernete +9
This is the second in a series of papers devoted to explore a set of six dusty models of active galactic nuclei (AGN) with available spectral energy distributions (SEDs). These mod…
Extreme quasars at high redshift
M. L. Martınez-Aldama, A. Del Olmo, P. Marziani +5
Context:Quasars radiating at extreme Eddington ratios (xA) are likely a prime mover of galactic evolution and have been hailed as potential distance indicators. Their properties ar…
Multiband Comparative Study of Optical Microvariability in RL vs. RQ Quasars
A. Ramirez, J. A. de Diego, D. Dultzin +1
We present the results of an optical multi-band (BVR) photometric monitoring program of 22 core-dominated radio-loud quasars (CRLQs) and 22 radio-quiet quasars (RQQs). The aim was…
The Broad Line Region of Quasars
P. Marziani, J. W. Sulentic, D. Dultzin
The last decade saw long-awaited improvements in our understanding of active galactic nuclei (AGN) spectral properties. This contribution reviews some important observational resul…
Dark energy constraints from quasar observations
B. Czerny, M. L. MartÃnez-Aldama, G. Wojtkowska +9
Recent measurements of the parameters of the Concordance Cosmology Model (CDM) done in the low-redshift Universe with Supernovae Ia/Cepheids, and in the distant Universe done w…
Spectroscopic monitoring of the Blazar 3C 454.3
E. Benitez, V. H. Chavushyan, C. M. Raiteri +5
We performed an optical spectroscopic monitoring of the blazar 3C 454.3 from September 2003 to July 2008. Sixteen optical spectra were obtained during different runs, which constit…
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…
Studying the evolution of galaxies in compact groups over the past 3 Gyr - II. The importance of environment in the suppression of star formation
T. Bitsakis, D. Dultzin, L. Ciesla +9
We present an in depth study on the evolution of galaxy properties in compact groups over the past 3 Gyr. We are using the largest multi-wavelength sample to-date, comprised 1770 g…
Spectral Optical Monitoring of the Narrow Line Seyfert 1 galaxy Ark 564
A. I. Shapovalova, L. C. Popovic, A. N. Burenkov +14
We present the results of a long-term (1999--2010) spectral optical monitoring campaign of the active galactic nucleus (AGN) Ark 564, which shows a strong Fe II line emission in th…
The most powerful quasar outflows as revealed by the Civ λ1549 resonance line
P. Marziani, M. A. Martinez Carballo, J. W. Sulentic +3
While quasar outflows may be quasi-ubiquitous, there are significant differences on a source-by- source basis. These differences can be organized along the 4D Eigenvector 1 sequenc…
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…
Multiwavelength observations of a TeV-Flare from W Comae
VERITAS collaboration, V. A. Acciari, E. Aliu +167
We report results from an intensive multiwavelength campaign on the intermediate-frequency-peaked BL Lacertae object W Com (z=0.102) during a strong outburst of very high energy ga…
Optical Microvariability in Quasars: Spectral Variability
A. Ramirez, D. Dultzin, J. A. de Diego
We present a method that we developed to discern where the optical microvariability (OM) in quasars originates: in the accretion disk (related to thermal processes) or in the jet (…
Broad Line Region Physical Conditions along the Quasar Eigenvector 1 Sequence
P. Marziani, J. W. Sulentic, C. A. Negrete +3
[Abridged] We compare broad emission line profiles and estimate line ratios for all major emission lines between Ly-alpha and H-beta in a sample of six quasars. The sources were ch…
The Activity of the Neighbours of Seyfert Galaxies
E. Koulouridis, M. Plionis, V. Chavushyan +4
We present a follow-up study on a series of papers concerning the role of close interactions as a possible triggering mechanism of AGN activity. We have already studied the close (…
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…
Studying the evolution of galaxies in compact groups over the past 3 Gyr. I. The nuclear activity
T. Bitsakis, D. Dultzin, L. Ciesla +3
We present the first -- of a series -- study of the evolution of galaxies in compact groups over the past 3 Gyr. This paper focuses on the evolution of the nuclear activity and how…
Blue outliers among intermediate redshift quasars
P. Marziani, J. W. Sulentic, G. M. Stirpe +3
[Oiii]λλ4959,5007 "blue outliers" -- that are suggestive of outflows in the narrow line region of quasars -- appear to be much more common at intermediate z (high luminosity) tha…
Modelling the strongest silicate emission features of local type 1 AGN
M. MartÃnez-Paredes, O. González-MartÃn, D. Esparza-Arredondo +8
We measure the 10 and m silicate features in a sample of 67 local () type 1 active galactic nuclei (AGN) with available {\it Spitzer} spectra dominated by non-stellar…
The Environment of Sy1, Sy2 & Bright IRAS Galaxies
E. Koulouridis, V. Chavushyan, M. Plionis +4
We present a 3-dimensional study of the local (< 100 kpc) environment of Sy1, Sy2 and Bright IRAS Galaxies. For this purpose we use three galaxy samples (Sy1, Sy2, BIRG) located at…
Early Science with the Large Millimeter Telescope: an energy-driven wind revealed by massive molecular and fast X-ray outflows in the Seyfert Galaxy IRAS 17020+4544
A. L. Longinotti, O. Vega, Y. Krongold +23
We report on the coexistence of powerful gas outflows observed in millimeter and X-ray data of the Radio-Loud Narrow Line Seyfert 1 Galaxy IRAS 17020+4544. Thanks to the large coll…
HE0359-3959: an extremely radiating quasar
M. L. MartÃnez-Aldama, A. Del Olmo, P. Marziani +3
We present a multiwavelength spectral study of the quasar HE0359-3959, which has been identified as an extreme radiating source at intermediate redshift (z=1.5209). Along the spect…
Detailed Characterization of H_beta emission line profile in low z SDSS quasars
S. Zamfir, J. W. Sulentic, P. Marziani +1
We explore the properties of the H_beta emission line profile in a large, homogeneous and bright sample of N~470 low redshift quasars extracted from Sloan Digital Sky Survey (DR5).…
The Lockman-SpReSO project. Description, target selection, observations and preliminary results
M. González-Otero, C. P. Padilla-Torres, J. Cepa +26
Context. Extragalactic surveys are a key tool for better understanding the evolution of galaxies. Both deep and wide-field surveys serve to provide a clearer emerging picture of th…
Multiwavelength observations of 3C 454.3. III. Eighteen months of AGILE monitoring of the "Crazy Diamond"
S. Vercellone, F. D'Ammando, V. Vittorini +110
We report on 18 months of multiwavelength observations of the blazar 3C 454.3 (Crazy Diamond) carried out in July 2007-January 2009. We show the results of the AGILE campaigns whic…
Observations of the first electromagnetic counterpart to a gravitational wave source by the TOROS collaboration
M. C. DÃaz, L. M. Macri, D. Garcia Lambas +52
We present the results of prompt optical follow-up of the electromagnetic counterpart of the gravitational-wave event GW170817 by the Transient Optical Robotic Observatory of the S…
Super-Eddington Accretion in Quasars
P. Marziani, K. Garnica Luna, A. Floris +5
This review provides an observational perspective on the fundamental properties of super-Eddington accretion onto supermassive black holes in quasars. It begins by outlining the se…
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…
UV spectral diagnostics for low redshift quasars: estimating physical conditions and radius of the Broad Line Region
P. Marziani, J. W. Sulentic, C. A. Negrete +5
The UV spectral range (1100 - 3000 A) contains the strongest resonance lines observed in active galactic nuclei (AGN). Analysis of UV line intensity ratios and profile shapes in qu…