16 papers
An Exploratory Analysis of New Large Gaia-informed Quasar Samples in SDSS-V
Shir Aviram, Benny Trakhtenbrot, Tom Dwelly +22
The paper presents an exploratory analysis of a new all‑sky quasar catalog from SDSS‑V, using Gaia‑ and WISE‑based selection methods (GUA and Skewt‑QSO) that yield over 250,000 spe…
Spectroscopic Analysis of Fermi-detected Blazars using SDSS-V
Mohammed Iddrisu Nlowie, James Aird, Eli Kasai +17
The paper introduces a multi-component spectral fitting pipeline applied to SDSS‑V spectra of Fermi‑detected blazars, reclassifying many misidentified sources, improving redshift e…
The Twentieth Data Release of the Sloan Digital Sky Survey: First All-Sky BOSS Spectra, eROSITA-SDSS-V Mapper Coordinated Observations, and a Preview of the Local Volume Mapper
SDSS Collaboration, Mojgan Aghakhanloo, David Aguilar +273
The paper describes the twentieth data release (DR20) of the Sloan Digital Sky Survey, providing over 3 million new optical spectra from the SDSS‑V Milky Way, Black Hole, and Local…
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…
Strong X-ray Variability of I Zwicky 1: Obscuration from Clumpy Accretion-Disk Winds
Jian Huang, Bin Luo, W. N. Brandt +2
Obscuration from clumpy accretion-disk winds has been invoked to explain the extreme X-ray weakness and X-ray variability observed in a substantial fraction of super-Eddington accr…
SDSS-V: Revealing a weak accretion state in X-ray selected red quasars
Paloma Guetzoyan, James Aird, Amy L. Rankine +17
Red quasars (rQSOs) have been recognized as a short-lived, early stage in the evolutionary cycle of Active Galactic Nuclei (AGN), with fundamental differences in their intrinsic pr…