48 citations · 278 across the 32 of their papers we have counts for
16 papers · 1 filter
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…
A Meta-Learning Framework for Multitask Reverberation Mapping in Active Galactic Nuclei
Aman N. Raju, Andjelka B. Kovačević, Dragana Ilić +8
The Vera C. Rubin Observatory Legacy Survey of Space and Time (LSST) is expected to observe active galactic nuclei (AGN) at sky densities of approximately 1000-4000 per sq. deg, en…
Spectral Handling and Estimation of AGN Parameters (SHEAP), The first AGN fitting GPU-based code
F. Ávila-Vera, P. Sánchez-Sáez, V. Motta +1
In the coming years, the number of discovered active galactic nuclei (AGN) is expected to increase significantly due to upcoming spectroscopic surveys. This growth will challenge c…
Scavenger hunt: Selection of obscured active galactic nuclei combining multiband optical variability and colors
Demetra De Cicco, Stefano Cavuoti, Maurizio Paolillo +3
As wide-field optical surveys such as Vera Rubin Observatory's Legacy Survey of Space and Time (LSST) begin operations, time-domain astronomy is facing a data revolution, paving th…
The evolution of obscured AGN across cosmic time -- A large quasar survey for the 2040s
Tanya Urrutia, Darshan Kakkad, Paula Sánchez-Sáez +21
We propose a large quasar demographic optical multi-object spectroscopic (MOS) survey targeting over 50 million AGN candidates up to the highest redshifts possible in the optical (…
Unlocking AGN Variability with Custom ZTF Photometry for High-Fidelity Light Curves and Robust Selection
P. Arévalo, P. Sánchez-Sáez, B. Sotomayor +3
(Abridged)We explore the potential of optical variability selection methods to identify AGN, including those challenging to detect with conventional techniques. Using the unprecede…
Selection of optically variable active galactic nuclei via a random forest algorithm
Demetra De Cicco, Gaetano Zazzaro, Stefano Cavuoti +5
Context. A defining characteristic of active galactic nuclei (AGN) that distinguishes them from other astronomical sources is their stochastic variability, which is observable acro…
The Intermediate-Mass Black Hole Reverberation Mapping Project: First Detection of Mid-Infrared Lags in Prototypical IMBHs in NGC 4395 and POX 52
Jingbo Sun, Hengxiao Guo, Wenwen Zuo +25
The search for robust evidence of intermediate-mass black holes (IMBHs) is crucial for understanding black hole seeding process and the formation of supermassive black holes in the…
AT 2021hdr: A candidate tidal disruption of a gas cloud by a binary super massive black hole system
L. Hernández-García, A. M. Muñoz-Arancibia, P. Lira +25
With a growing number of facilities able to monitor the entire sky and produce light curves with a cadence of days, in recent years there has been an increased rate of detection of…
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…
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…
A structure function analysis of VST-COSMOS AGN
D. De Cicco, F. E. Bauer, M. Paolillo +6
We present our sixth work in a series dedicated to variability studies of active galactic nuclei (AGN) based on the survey of the COSMOS field by the VLT Survey Telescope (VST). It…
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…