Sloan Digital Sky Survey Standard Star Catalog for Stripe 82: The Dawn of Industrial 1% Optical Photometry

Ivezić, Željko; Smith, J. Allyn; Miknaitis, G.; Lin, Huan; Tucker, D. L.; Lupton, Robert H.; Gunn, James E.; Knapp, G. R.; Strauss, Michael A.; Sesar, Branimir; Doi, Mamoru; Tanaka, Masayuki; Fukugita, M.; Holtzman, Jon A.; Kent, S.; Yanny, B.; Schlegel, David J.; Finkbeiner, Douglas P.; Padmanabhan, Nikhil; Rockosi, Constance M.; Jurić, Mario; Bond, Nicholas A.; Lee, Brian; Stoughton, Chris; Jester, Sebastian; Harris, Hugh C.; Harding, Paul; Morrison, Heather; Brinkmann, J.; Schneider, Donald P.; York, Donald G.

doi:10.1086/519976

Cited by 315 publications

(387 citation statements)

References 46 publications

Supporting

Mentioning

381

Contrasting

Order By: Relevance

“…However, errors at the brighter magnitudes are overestimated and those at fainter magnitudes (>18) are underestimated (Palaversa et al 2013;Drake et al 2014;Vaughan et al 2016). We have derived a multiplicative correction factor from CRTS observations of 350 000 sources in the Stripe 82 Standard Star catalogue (Ivezic et al 2007) that ensures that the mode of the reduced chi-squared variability in magnitude bins of width of mag = 0.05 is centred at unity (see Fig. 1).…”

Section: Catalina Real-time Transient Surveymentioning

confidence: 99%

Understanding extreme quasar optical variability with CRTS – I. Major AGN flares

Graham¹,

Djorgovski²,

Drake³

et al. 2017

Monthly Notices of the Royal Astronomical Society

118

133

View full text Add to dashboard Cite

There is a large degree of variety in the optical variability of quasars and it is unclear whether this is all attributable to a single (set of) physical mechanism(s). We present the results of a systematic search for major flares in active galactic nucleus (AGN) in the Catalina Real-time Transient Survey as part of a broader study into extreme quasar variability. Such flares are defined in a quantitative manner as being atop of the normal, stochastic variability of quasars. We have identified 51 events from over 900 000 known quasars and high-probability quasar candidates, typically lasting 900 d and with a median peak amplitude of m = 1.25 mag. Characterizing the flare profile with a Weibull distribution, we find that nine of the sources are well described by a single-point single-lens model. This supports the proposal by Lawrence et al. that microlensing is a plausible physical mechanism for extreme variability. However, we attribute the majority of our events to explosive stellar-related activity in the accretion disc: superluminous supernovae, tidal disruption events and mergers of stellar mass black holes.

show abstract

Section: Catalina Real-time Transient Surveymentioning

confidence: 99%

Understanding extreme quasar optical variability with CRTS – I. Major AGN flares

Graham¹,

Djorgovski²,

Drake³

et al. 2017

Monthly Notices of the Royal Astronomical Society

118

133

View full text Add to dashboard Cite

show abstract

“…We investigated the accuracy of our photometric calibration by comparing aperture photometry of stars in our source catalogues with the SDSS standard star catalogue for Stripe 82 (Ivezić et al 2007). The source catalogues are based on SExtractor photometry on our co-added images.…”

Section: Photometric Accuracymentioning

confidence: 99%

The IAC Stripe 82 Legacy Project: a wide-area survey for faint surface brightness astronomy

Fliri¹,

Trujillo²

2015

Mon. Not. R. Astron. Soc.

130

118

View full text Add to dashboard Cite

We present new deep co-adds of data taken within Stripe 82 of the Sloan Digital Sky Survey (SDSS), especially stacked to reach the faintest surface brightness limits of this data set. Stripe 82 covers 275 deg 2 within -50 • RA +60 • and -1.• 25 Dec. +1.• 25. We discuss the steps of our reduction which puts special emphasis on preserving the characteristics of the background (sky + diffuse light) in the input images using a non-aggressive sky subtraction strategy. Our reduction reaches a limit of ∼28.5 mag arcsec −2 (3σ, 10×10 arcsec 2 ) in the r band. The effective surface brightness limit (50% completeness for exponential light distribution) lies at < µ e (r) >∼25.5 mag arcsec −2 . For point sources, we reach 50% completeness limits (3σ level) of (24.2, 25.2, 24.7, 24.3, 23.0) mag in (u, g, r, i, z). This is between 1.7 and 2.0 mag deeper than the single-epoch SDSS releases. The co-adds show point spread functions (PSFs) with median full width at half-maximum values ranging from 1 arcsec in i and z to 1.3 arcsec in the u band. The imaging data are made publicly available at http://www.iac.es/proyecto/stripe82. The release includes deep co-adds and representations of the PSF for each field. Additionally, we provide object catalogues with stars and galaxies confidently separated until g∼23 mag. The IAC Stripe 82 co-adds offer a rather unique possibility to study the low surface brightness Universe, exemplified by the discovery of stellar streams around NGC0426 and NGC0936. We also discuss further science cases like stellar haloes and disc truncations, low surface brightness galaxies, the intra-cluster light in galaxy clusters and the diffuse emission of Galactic dust known as Galactic Cirrus.

show abstract

“…Next, the light curve is obtained from y = Lr, where r is a vector of Gaussian deviations with the variance of unity (e.g., Zu et al 2011). Finally, we add the photometric noise ni(yi) dependent on the magnitude yi, yi = yi + G(ni(yi)), that is drawn from a Gaussian (G) distribution of the true SDSS photometric noise (Ivezić et al 2007). …”

Section: Methodsmentioning

confidence: 99%

“…With the exception of the case with β = 1, they are regarded as the non-DRW stochastic processes. The light curves have the mean magnitude r = 17 mag and the noise properties of the SDSS Stripe82 quasars (Ivezić et al 2007). The input time-scale is τ = 500 days, the asymptotic variability amplitude is SF∞ = 0.18 mag, the light curve length is 8000 days, and the cadence is 20 days (hence 400 points).…”

Section: Methodsmentioning

confidence: 99%

A degeneracy in DRW modelling of AGN light curves

Kozłowski

2016

Mon. Not. R. Astron. Soc.

View full text Add to dashboard Cite

Individual light curves of active galactic nuclei (AGNs) are nowadays successfully modelled with the damped random walk (DRW) stochastic process, characterized by the power exponential covariance matrix of the signal, with the power β = 1. By Monte Carlo simulation means, we generate mock AGN light curves described by non-DRW stochastic processes (0.5 ≤ β ≤ 1.5 and β = 1) and show they can be successfully and well modelled as a single DRW process, obtaining comparable goodness of fits. A good DRW fit, in fact, may not mean that DRW is the true underlying process leading to variability and it cannot be used as a proof for it. When comparing the input (non-DRW) and measured (DRW) process parameters, the recovered time-scale (amplitude) increases (decreases) with the increasing input β. In practice, this means that the recovered DRW parameters may lead to biased (or even non-existing) correlations of the variability and physical parameters of AGNs if the true AGN variability is caused by non-DRW stochastic processes. The proper way of identifying the processes leading to variability are model-independent structure functions and/or power spectral densities and then using such information on the covariance matrix of the signal in light curve modelling.

show abstract

Sloan Digital Sky Survey Standard Star Catalog for Stripe 82: The Dawn of Industrial 1% Optical Photometry

Cited by 315 publications

References 46 publications

Understanding extreme quasar optical variability with CRTS – I. Major AGN flares

Understanding extreme quasar optical variability with CRTS – I. Major AGN flares

The IAC Stripe 82 Legacy Project: a wide-area survey for faint surface brightness astronomy

A degeneracy in DRW modelling of AGN light curves

Contact Info

Product

Resources

About