41 citations · 220 across the 18 of their papers we have counts for
19 papers
Continuum Variability in AGN: Evidence for Systematically Suppressed Fluctuations in the BAL Population
A. Aliaga, P. Arévalo, M. L. Martínez-Aldama +2
We aim to compare the flux variability of Broad Absorption Line quasars (BAL) to non-BAL quasars, controlling for black hole parameters to inform models concerning the generation o…
The X-ray-Weak Tail of the Quasar Population: Physical Properties and Redshift Evolution of Variability-Selected AGN in eFEDS
P. Arévalo, J. Buchner, M. Salvato +10
(abridged) Aims: To characterize variability-selected AGN candidates within the eROSITA Final Equatorial-Depth Survey (eFEDS), leveraging the synergy between optical variability an…
VAR-PZnn: A machine-learning framework for AGN photometric redshifts using color and variability-based features
S. Satheesh-Sheeba, P. Sánchez-Sáez, R. J. Assef +39
Photometric redshift estimation for active galactic nuclei (AGNs) remains a fundamental challenge for current and upcoming large-scale photometric surveys. Traditional spectral ene…
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…
Discovery of extreme Quasi-Periodic Eruptions in a newly accreting massive black hole
Lorena Hernández-García, Joheen Chakraborty, Paula Sánchez-Sáez +27
Quasi-periodic eruptions (QPEs) are rapid, recurring X-ray bursts from supermassive black holes, believed to result from interactions between accretion disks and surrounding matter…
Probing the rest-frame wavelength dependence of quasar variability : Insights from the Zwicky Transient Facility Survey
P. Patel, P. Lira, P. Arévalo +3
Context: Quasar variability can potentially unlock crucial insights into the accretion process. Understanding how this variability is influenced by wavelength is crucial for valida…
SDSS1335+0728: The awakening of a black hole
P. Sánchez-Sáez, L. Hernández-García, S. Bernal +22
The galaxy SDSS1335+0728, which had exhibited no prior optical variations during the preceding two decades, began showing significant nuclear variability in the Zwicky Transient Fa…
A Newborn AGN in a Starforming Galaxy
P. Arévalo, E. López-Navas, M. L. Martínez-Aldama +8
We report on the finding of a newborn AGN, i.e. current AGN activity in a galaxy previously classified as non-active, and characterize its evolution. Black hole ignition event cand…
BASS-XL: X-ray variability properties of unobscured Active Galactic Nuclei
Alessia Tortosa, Claudio Ricci, Patricia Arévalo +15
We investigate the X-ray variability properties of Seyfert1 Galaxies belonging to the BAT AGN Spectroscopic Survey (BASS). The sample includes 151 unobscured (N c…
Improving the selection of changing-look AGNs through multi-wavelength photometric variability
E. López-Navas, P. Sánchez-Sáez, P. Arévalo +13
We present second epoch optical spectra for 30 changing-look (CL) candidates found by searching for Type-1 optical variability in a sample of active galactic nuclei (AGNs) spectros…
Persistent and occasional: searching for the variable population of the ZTF/4MOST sky using ZTF data release 11
P. Sánchez-Sáez, J. Arredondo, A. Bayo +13
We present a variability, color and morphology based classifier, designed to identify transients, persistently variable, and non-variable sources, from the Zwicky Transient Facilit…
Optical variability in Quasars: Scaling with black hole mass and Eddington ratio depend on the observed timescales
Patricia Arévalo, Paulina Lira, Paula Sánchez-Sáez +4
Quasars emission is highly variable, and this variability gives us clues to understand the accretion process onto supermassive black holes. We can expect variability properties to…
Multiwavelength monitoring of the nucleus in PBC J2333.9-2343: the giant radio galaxy with a blazar-like core
L. Hernández-García, F. Panessa, G. Bruni +12
PBC J2333.9-2343 is a giant radio galaxy at z = 0.047 with a bright central core associated to a blazar nucleus. If the nuclear blazar jet is a new phase of the jet activity, then…
A closer look at NGC 7314 nuclear region: a multiwavelength analysis of the Seyfert nucleus and its surroundings
Patrícia da Silva, R. B. Menezes, Y. Díaz +4
The central regions of galaxies harbouring active galactic nuclei (AGNs) can be quite complex, especially at high activity, presenting, besides variability, a variety of phenomena…
The Type 1 and Type 2 AGN dichotomy according to their ZTF optical variability
E. López-Navas, P. Arévalo, S. Bernal +4
The scarce optical variability studies in spectrally classified Type 2 active galactic nuclei (AGNs) have led to the discovery of anomalous objects that are incompatible with the s…
Constraining the X-ray reflection in low accretion rate AGN using XMM-Newton, NuSTAR and Swift
Y. Díaz, L. Hernández-García, P. Arévalo +8
An interesting feature in active galactic nuclei (AGN) accreting at low rate is the weakness of the reflection features in their X-ray spectra, which can result from the gradual di…
Confirming new changing--look AGNs discovered through optical variability using a random-forest based light curve classifier
E. López-Navas, M. L. Martínez-Aldama, S. Bernal +6
Determining the frequency and duration of changing--look (CL) active galactic nuclei (AGNs) phenomena, where the optical broad emission lines appear or disappear, is crucial to und…
A multiwavelength-motivated X-ray model for the Circinus Galaxy
Carolina Andonie, Claudio Ricci, Stéphane Paltani +4
Reprocessed X-ray emission in Active Galactic Nuclei (AGN) can provide fundamental information about the circumnuclear environments of supermassive black holes. Recent mid-infrared…
An Eddington ratio-driven origin for the relation in quiescent and star forming active galaxies
Rosamaria Carraro, Francesco Shankar, Viola Allevato +5
A mild correlation exists in active galaxies between the mean black hole accretion, as traced by the mean X-ray luminosity , and the host galaxy stell…