41 citations · 220 across the 18 of their papers we have counts for
13 papers · 1 filter
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…
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…
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…
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…
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…
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…
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…