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Related papers: How far is quasar UV/optical variability from damp…

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We characterize the optical variability properties of eight lobe-dominated radio quasars (QSOs): B2 0709$+$37, FBQS J095206.3$+$235245, PG 1004$+$130, [HB89] 1156$+$631, [HB89] 1425$+$267, [HB89] 1503$+$691, [HB89] 1721$+$343, 4C $+$74.26,…

In this manuscript, we study properties of long-term optical variability of a large sample of 106 SDSS spectroscopically confirmed AGN with double-peaked broad low-ionization emission lines (double-peaked emitters). The long-term optical…

Astrophysics of Galaxies · Physics 2016-10-12 XueGuang Zhang , LongLong Feng

Context. The steep-spectrum radio quasars (SSRQs) are powerful radio sources, with thermal emission from accretion disk and jet nonthermal emission likely both contributing in the Ultraviolet (UV)/optical luminosity, however the former may…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-15 Minfeng Gu , Shuang-Liang Li

The stochastic photometric variability of quasars is known to follow a random-walk phenomenology on emission timescales of months to years. Some high-cadence restframe optical monitoring in the past has hinted at a suppression of…

Astrophysics of Galaxies · Physics 2024-11-13 Ji-Jia Tang , Christian Wolf , John Tonry

Quasars are variable on timescales from days to years in UV/optical, and generally appear bluer while they brighten. The physics behind the variations in fluxes and colors remains unclear. Using SDSS g and r band photometric monitoring data…

Astrophysics of Galaxies · Physics 2015-06-22 Yu-Han Sun , Jun-Xian Wang , Xiao-Yang Chen , Zhen-Ya Zheng

We present a new approach to analysing the dependence of quasar variability on rest-frame wavelengths. We exploited the spectral archive of the Sloan Digital Sky Survey (SDSS) to create a sample of more than 9000 quasars in the Stripe 82.…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-20 H. Meusinger , A. Hinze , A. de Hoon

We use a sample of 3791 quasars from the Sloan Digital Sky Survey (SDSS) Early Data Release (EDR), and compare their photometry to historic plate material for the same set of quasars in order to study their variability properties. The time…

Astrophysics · Physics 2009-11-07 Wim de Vries , Bob Becker , Rick White

In recent work done by Sun et. al., the color variation of quasars, namely the bluer-when-brighter trend, was found to be timescale-dependent using SDSS $g/r$ band light curves in the Stripe 82. Such timescale dependence, i.e., bluer…

Astrophysics of Galaxies · Physics 2016-12-07 Fei-Fan Zhu , Jun-Xian Wang , Zhen-Yi Cai , Yu-Han Sun

Significant progress in the description of quasar variability has been recently made by employing SDSS and POSS data. Common to most studies is a fundamental assumption that photometric observations at two epochs for a large number of…

Astrophysics · Physics 2009-11-13 C. MacLeod , Z. Ivezic , W. de Vries , B. Sesar , A. Becker

UV/optical variability in quasars is a well-observed phenomenon, yet its primeval origins remain unclear. This study investigates whether the accretion disk turbulence, which is responsible for UV/optical variability, is influenced by the…

Astrophysics of Galaxies · Physics 2024-08-05 Liang Wu , Jun-Xian Wang , Wen-Ke Ren , Wen-Yong Kang

Observations have shown that UV/optical variation amplitude of quasars depend on several physi- cal parameters including luminosity, Eddington ratio, and likely also black hole mass. Identifying new factors which correlate with the…

High Energy Astrophysical Phenomena · Physics 2018-11-28 Wen-yong Kang , Jun-Xian Wang , Zhen-Yi Cai , Heng-Xiao Guo , Fei-Fan Zhu , Xin-Wu Cao , Wei-Min Gu , Feng Yuan

We compare quasar selection techniques based on their optical variability using data from the Catalina Real-time Transient Survey (CRTS). We introduce a new technique based on Slepian wavelet variance (SWV) that shows comparable or better…

Cosmology and Nongalactic Astrophysics · Physics 2014-03-05 Matthew J. Graham , S. G. Djorgovski , Andrew J. Drake , Ashish A. Mahabal , Melissa Chang , Daniel Stern , Ciro Donalek , Eilat Glikman

The optical variability of 29 flat spectrum radio quasars in SDSS Stripe 82 region are investigated by using DR7 released multi-epoch data. All FSRQs show variations with overall amplitude ranging from 0.24 mag to 3.46 mag in different…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-27 Minfeng Gu , Y. L. Ai

It has been found that some quasars are undergoing quasi-periodic variations (most of them with damped amplitudes) in optical bands from long-term monitoring campaigns, but how to explain the origin of such light curve variations still…

High Energy Astrophysical Phenomena · Physics 2024-12-25 Yue-Chang Peng , Jian-Min Wang , Pu Du , Shuo Zhai , Yan-Rong Li

The UV/optical light curves of Active Galactic Nuclei (AGNs) are commonly described by the Damped Random Walk (DRW) model. However, the physical interpretation of the damping timescale, a key parameter in the DRW model, remains unclear.…

High Energy Astrophysical Phenomena · Physics 2024-03-05 Shuying Zhou , Mouyuan Sun , Zhen-Yi Cai , Guowei Ren , Jun-Xian Wang , Yongquan Xue

We quantify the variability of faint unresolved optical sources using a catalog based on multiple SDSS imaging observations. The catalog covers SDSS Stripe 82, and contains 58 million photometric observations in the SDSS ugriz system for…

We measure quasar variability using the Panoramic Survey Telescope and Rapid Response System 1 Survey (Pan-STARRS1 or PS1) and the Sloan Digital Sky Survey (SDSS) and establish a method of selecting quasars via their variability in 10,000…

The spectral variability of a sample of 44 flat-spectrum radio quasars (FSRQs) and 18 steep-spectrum radio quasars (SSRQs) in the SDSS stripe 82 region is investigated. Twenty-five of 44 FSRQs show a bluer-when-brighter trend (BWB), while…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-15 Minfeng Gu

This paper presents results of a search for short-term variability in the optical band of selected high-luminosity, high-redshift radio-quiet quasars. Each quasar has been monitored typically for 2 - 4 hours with a time resolution of 2 - 5…

Astrophysics · Physics 2009-11-10 R. Bachev , A. Strigachev , E. Semkov

Using 16,421 spectra from a sample of 340 quasars ($1.62<z<3.30$) from the SDSS Reverberation Mapping Project, we present an analysis of quasar spectral variability. We confirm the intrinsic Baldwin Effect and brighter-means-bluer trends in…