196 citations · 751 across the 34 of their papers we have counts for
35 papers
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…
Simultaneous radio, optical and X-ray monitoring of hard X-ray selected AGN: a variability study
L. Hernández-García, F. Panessa, D. Williams-Baldwin +2
AGN emission is intrinsically variable across the electromagnetic spectrum. Mapping the coupling between the accretion disk, the X-ray corona, and ejection flows is key to understa…
Querying an astronomical database using large language models: the ALeRCE text-to-SQL system
P. A. Estevez, J. Espejo-Moreira, S. Sanfeliu-Alvarez +10
We develop a text-to-SQL (structured query language) system based on large language models (LLMs) using in-context learning and apply it to the Automatic Learning for the Rapid Cla…
Scalable and Robust Multiband Modeling of AGN Light Curves in Rubin-LSST
Weixiang Yu, John J. Ruan, Colin J. Burke +22
The Vera C. Rubin Observatory's Legacy Survey of Space and Time (LSST) will monitor tens of millions of active galactic nuclei (AGNs) for a period of 10 years with an average caden…
Image-Based Multi-Survey Classification of Light Curves with a Pre-Trained Vision Transformer
Daniel Moreno-Cartagena, Guillermo Cabrera-Vives, Alejandra M. Muñoz Arancibia +10
We explore the use of Swin Transformer V2, a pre-trained vision Transformer, for photometric classification in a multi-survey setting by leveraging light curves from the Zwicky Tra…
Discovery of Quasi-periodic Eruptions in the Tidal Disruption Event and Extreme Coronal Line Emitter AT2022upj: implications for the QPE/TDE fraction and a connection to ECLEs
Joheen Chakraborty, Erin Kara, Riccardo Arcodia +10
Quasi-periodic eruptions (QPEs) are recurring soft X-ray transients emerging from the vicinity of supermassive black holes (SMBHs) in nearby, low-mass galaxy nuclei; about ten QPE…
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…
Rapidly varying ionization features in a Quasi-periodic Eruption: a homologous expansion model for the spectroscopic evolution
Joheen Chakraborty, Peter Kosec, Erin Kara +9
Quasi-Periodic Eruptions (QPEs) are recurring bursts of soft X-ray emission from supermassive black holes (SMBHs), which a growing class of models explains via extreme mass-ratio i…
Clues of the restarting active galactic nucleus activity of Mrk 1498 from GTC/MEGARA integral field spectroscopy data
S. Cazzoli, L. Hernández-García, I. Márquez +4
Some giant radio galaxies selected at X-rays with an AGN show signs of a restarted nuclear activity. One object in this peculiar class is Mrk1498, a giant low-frequency double radi…
Physical Properties of Type II Supernovae Inferred from ZTF and ATLAS Photometric Data
Javier Silva-Farfán, Francisco Förster, Takashi J. Moriya +6
We report an analysis of a sample of 186 spectroscopically confirmed Type II supernova (SN) light curves (LCs) obtained from a combination of Zwicky Transient Facility (ZTF) and As…
Exploring Changing-look Active Galactic Nuclei with the Sloan Digital Sky Survey V: First Year Results
Grisha Zeltyn, Benny Trakhtenbrot, Michael Eracleous +32
"Changing-look" active galactic nuclei (CL-AGNs) challenge our basic ideas about the physics of accretion flows and circumnuclear gas around supermassive black holes. Using first-y…
Multi-Class Deep SVDD: Anomaly Detection Approach in Astronomy with Distinct Inlier Categories
Manuel Pérez-Carrasco, Guillermo Cabrera-Vives, Lorena Hernández-García +8
With the increasing volume of astronomical data generated by modern survey telescopes, automated pipelines and machine learning techniques have become crucial for analyzing and ext…
A Transient "Changing-look'' Active Galactic Nucleus Resolved on Month Timescales from First-year Sloan Digital Sky Survey V Data
Grisha Zeltyn, Benny Trakhtenbrot, Michael Eracleous +32
We report the discovery of a new ``changing-look'' active galactic nucleus (CLAGN) event, in the quasar SDSS J162829.17+432948.5 at z=0.2603, identified through repeat spectroscopy…
DELIGHT: Deep Learning Identification of Galaxy Hosts of Transients using Multi-resolution Images
Francisco Förster, Alejandra M. Muñoz Arancibia, Ignacio Reyes +25
We present DELIGHT, or Deep Learning Identification of Galaxy Hosts of Transients, a new algorithm designed to automatically and in real-time identify the host galaxies of extragal…
Daily variability at milli-arcsecond scales in the radio quiet NLSy1 Mrk 110
Francesca Panessa, Miguel Perez-Torres, Lorena Hernandez-Garcia +14
The origin of radio emission in the majority of Active Galactic Nuclei (AGN) is still poorly understood. Various competing mechanisms are likely involved in the production of radio…
The Automatic Learning for the Rapid Classification of Events (ALeRCE) Alert Broker
F. Förster, G. Cabrera-Vives, E. Castillo-Navarrete +37
We introduce the Automatic Learning for the Rapid Classification of Events (ALeRCE) broker, an astronomical alert broker designed to provide a rapid and self--consistent classifica…
Constraining X-ray reflection in the low-luminosity AGN NGC 3718 using NuSTAR and XMM--Newton
Y. Diaz, P. Arévalo, L. Hernández-García +9
One distinctive feature of low-luminosity active galactic nuclei (LLAGN) is the relatively weak reflection features they may display in the X-ray spectrum, which can result from th…
Hard X-ray selected giant radio galaxies -- II. Morphological evidence of restarted radio activity
G. Bruni, F. Panessa, L. Bassani +10
About 6% of Radio Galaxies (RG) can reach linear sizes larger than 0.7 Mpc, and are then classified as Giant Radio Galaxies (GRG). The conditions that make possible the formation o…
Optical Spectroscopy of nearby type1-LINERs
S. Cazzoli, I. Márquez, J. Masegosa +6
We present the highlights from our recent study of 22 local (z0.025) type-1 LINERs from the Palomar Survey, on the basis of optical long-slit spectroscopic observations taken wi…
A young and obscured AGN embedded in the giant radio galaxy Mrk 1498
L. Hernández-García, F. Panessa, L. Bassani +10
Mrk 1498 is part of a sample of galaxies with extended emission line regions (extended outwards up to a distance of 7 kpc) suggested to be photo-ionized by an AGN that has fa…
A discovery of young radio sources in the cores of giant radio galaxies selected at hard X-rays
G. Bruni, F. Panessa, L. Bassani +9
Giant Radio Galaxies (GRG) are the largest single entities in the Universe, having a projected linear size exceeding 0.7 Mpc, which implies that they are also quite old objects. Th…
Probing restarting activity in hard X-ray selected giant radio galaxies
G. Bruni, F. Ursini, F. Panessa +13
With their sizes larger than 0.7 Mpc, Giant Radio Galaxies (GRGs) are the largest individual objects in the Universe. To date, the reason why they reach such enormous extensions is…
Optical spectroscopy of local type-1 AGN LINERs
S. Cazzoli, I. Marquez, J. Masegosa +6
The Balmer emission originated in the broad line region (BLR) of active galactic nuclei (AGNs) could be either weak and difficult to detect, or even absent, for low luminosity AGNs…
Variable broad lines and outflow in the weak blazar PBC J2333.9-2343
L. Hernández-García, G. Vietri, F. Panessa +12
PBC J2333.9-2343 is a peculiar active nucleus with two giant radio lobes and a weak blazar-like nucleus at their center. In the present work we show new optical, UV, and X-ray data…