Properties of Ellipticity Correlation with Atmospheric Structure From Gemini South
Abstract
Cosmic shear holds great promise for a precision independent measurement of {Omega}{sub m}, the mass density of the universe relative to the critical density. The signal is expected to be weak, so a thorough understanding of systematic effects is crucial. An important systematic effect is the atmosphere: shear power introduced by the atmosphere is larger than the expected signal. Algorithms exist to extract the cosmic shear from the atmospheric component, though a measure of their success applied to a range of seeing conditions is lacking. To gain insight into atmospheric shear, Gemini South imaging in conjunction with ground condition and satellite wind data were obtained. We find that under good seeing conditions PointSpreadFunction (PSF) correlations persist well beyond the separation typical of highlatitude stars. Under these conditions, ellipticity residuals based on a simple PSF interpolation can be reduced to within a factor of a few of the shotnoise induced ellipticity floor. We also find that the ellipticity residuals are highly correlated with wind direction. Finally, we correct stellar shapes using a more sophisticated procedure and generate shear statistics from stars. Under all seeing conditions in our data set the residual correlations lie everywhere below the target signal level. For goodmore »
 Authors:
 Publication Date:
 Research Org.:
 Stanford Linear Accelerator Center (SLAC)
 Sponsoring Org.:
 USDOE
 OSTI Identifier:
 897735
 Report Number(s):
 SLACPUB12297
astroph/0701157; TRN: US200705%%314
 DOE Contract Number:
 AC0276SF00515
 Resource Type:
 Journal Article
 Resource Relation:
 Journal Name: Submitted to Astrophys.J.
 Country of Publication:
 United States
 Language:
 English
 Subject:
 71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; ACCURACY; ALGORITHMS; INTERPOLATION; SATELLITES; SHAPE; SHEAR; STARS; STATISTICS; TARGETS; TURBULENCE; UNIVERSE; Astrophysics,ASTRO
Citation Formats
Asztalos, Stephen J., /LLNL, Livermore, de Vries, W.H., /UC, Davis /LLNL, Livermore, Rosenberg, L.J, Treadway, T., /LLNL, Livermore, Burke, D., /SLAC, Claver, C., Saha, A., /NOAO, Tucson, Puxley, P., and /Gemini Observ., La Serena. Properties of Ellipticity Correlation with Atmospheric Structure From Gemini South. United States: N. p., 2007.
Web. doi:10.1086/512048.
Asztalos, Stephen J., /LLNL, Livermore, de Vries, W.H., /UC, Davis /LLNL, Livermore, Rosenberg, L.J, Treadway, T., /LLNL, Livermore, Burke, D., /SLAC, Claver, C., Saha, A., /NOAO, Tucson, Puxley, P., & /Gemini Observ., La Serena. Properties of Ellipticity Correlation with Atmospheric Structure From Gemini South. United States. doi:10.1086/512048.
Asztalos, Stephen J., /LLNL, Livermore, de Vries, W.H., /UC, Davis /LLNL, Livermore, Rosenberg, L.J, Treadway, T., /LLNL, Livermore, Burke, D., /SLAC, Claver, C., Saha, A., /NOAO, Tucson, Puxley, P., and /Gemini Observ., La Serena. Wed .
"Properties of Ellipticity Correlation with Atmospheric Structure From Gemini South". United States.
doi:10.1086/512048. https://www.osti.gov/servlets/purl/897735.
@article{osti_897735,
title = {Properties of Ellipticity Correlation with Atmospheric Structure From Gemini South},
author = {Asztalos, Stephen J. and /LLNL, Livermore and de Vries, W.H. and /UC, Davis /LLNL, Livermore and Rosenberg, L.J and Treadway, T. and /LLNL, Livermore and Burke, D. and /SLAC and Claver, C. and Saha, A. and /NOAO, Tucson and Puxley, P. and /Gemini Observ., La Serena},
abstractNote = {Cosmic shear holds great promise for a precision independent measurement of {Omega}{sub m}, the mass density of the universe relative to the critical density. The signal is expected to be weak, so a thorough understanding of systematic effects is crucial. An important systematic effect is the atmosphere: shear power introduced by the atmosphere is larger than the expected signal. Algorithms exist to extract the cosmic shear from the atmospheric component, though a measure of their success applied to a range of seeing conditions is lacking. To gain insight into atmospheric shear, Gemini South imaging in conjunction with ground condition and satellite wind data were obtained. We find that under good seeing conditions PointSpreadFunction (PSF) correlations persist well beyond the separation typical of highlatitude stars. Under these conditions, ellipticity residuals based on a simple PSF interpolation can be reduced to within a factor of a few of the shotnoise induced ellipticity floor. We also find that the ellipticity residuals are highly correlated with wind direction. Finally, we correct stellar shapes using a more sophisticated procedure and generate shear statistics from stars. Under all seeing conditions in our data set the residual correlations lie everywhere below the target signal level. For good seeing we find that the systematic error attributable to atmospheric turbulence is comparable in magnitude to the statistical error (shape noise) over angular scales relevant to present lensing surveys.},
doi = {10.1086/512048},
journal = {Submitted to Astrophys.J.},
number = ,
volume = ,
place = {United States},
year = {Wed Jan 17 00:00:00 EST 2007},
month = {Wed Jan 17 00:00:00 EST 2007}
}

Cosmic shear holds great promise for a precision independent measurement of {Omega}{sub m}, the mass density of the universe relative to the critical density. The signal is expected to be weak, so a thorough understanding of systematic effects is crucial. An important systematic effect is the atmosphere: shear power introduced by the atmosphere is larger than the expected signal. Algorithms exist to extract the cosmic shear from the atmospheric component, though a measure of their success applied to a range of seeing conditions is lacking. To gain insight into atmospheric shear, Gemini South imaging in conjunction with ground condition andmore »

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