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Table · dataset · 2025

Optical variability of 190 Quasars in S82 region

Listed in IVOA Registry (Virtual Observatory)

We study the optical gri photometric variability of a sample of 190 quasars within the SDSS Stripe 82 region that have long-term photometric coverage during ~1998-2020 with SDSS, PanSTARRS-1, the Dark Energy Survey, and dedicated follow- up monitoring with Blanco 4m/DECam.

Description

With on average ~200 nightly epochs per quasar per filter band, we improve the parameter constraints from a Damped Random Walk (DRW) model fit to the light curves over previous studies with 10-15 yr baselines and <~ 100 epochs.

We find that the average damping time-scale {tau}_DRW_ continues to rise with increased baseline, reaching a median value of ~750 d (g band) in the rest frame of these quasars using the 20-yr light curves. Some quasars may have gradual, long-term trends in their light curves, suggesting that either the DRW fit requires very long baselines to converge, or that the underlying variability is more complex than a single DRW process for these quasars.

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Using a subset of quasars with better-constrained {tau}_DRW_ (less than 20 per cent of the baseline), we confirm a weak wavelength dependence of {tau}_DRW_ {prop.to} {lambda}^0.51+/-0.20^. We further quantify optical variability of these quasars over days to decades time-scales using structure function (SF) and power spectrum density (PSD) analyses. The SF and PSD measurements qualitatively confirm the measured (hundreds of days) damping time-scales from the DRW fits.

However, the ensemble PSD is steeper than that of a DRW on time-scales less than ~ a month for these luminous quasars, and this second break point correlates with the longer DRW damping time-scale.

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Optical
Provenance · 1 source records, 8 field assertions
SourceKeyLast seenRaw
IVOA Registry (Virtual Observatory)ivo://cds.vizier/j/mnras/514/16415 d agoJSON v1
FieldAssertionExtractorEvidence
access_levelsource · IVOA Registryconnector:ivoa_registry@1.0.0
concepts[field].local:field:astronomymapping · IVOA Registryconnector:ivoa_registry@1.0.0
concepts[modality].ivoa_waveband:opticalsource · IVOA Registryconnector:ivoa_registry@1.0.0
descriptionsource · IVOA Registryconnector:ivoa_registry@1.0.0rr.resource.res_description
license_textsource · IVOA Registryconnector:ivoa_registry@1.0.0
publication_datesource · IVOA Registryconnector:ivoa_registry@1.0.0
titlesource · IVOA Registryconnector:ivoa_registry@1.0.0rr.resource.res_title
updated_datesource · IVOA Registryconnector:ivoa_registry@1.0.0