TY - JOUR
T1 - Wavelength-dependent PSFs and their impact on weak lensing measurements
AU - Carlsten, S. G.
AU - Strauss, Michael A.
AU - Lupton, Robert H.
AU - Meyers, Joshua E.
AU - Miyazaki, Satoshi
N1 - Funding Information:
The Pan-STARRS1 Surveys (PS1) (Schlafly et al. 2012; Tonry et al. 2012; Magnier et al. 2013) have been made possible through contributions of the Institute for Astronomy, the University of Hawaii, the Pan-STARRS Project Office, the Max-Planck Society and its participating institutes, the Max Planck Institute for Astronomy, Heidelberg and the Max Planck Institute for Extraterrestrial Physics, Garching, The Johns Hopkins University, Durham University, the University of Edinburgh, Queen’s University Belfast, the Harvard-Smithsonian Center for Astrophysics, the Las Cumbres Observatory Global Telescope Network Incorporated, the National Central University of Taiwan, the Space Telescope Science Institute, the National Aeronautics and Space Administration under Grant No. NNX08AR22G issued through the Planetary Science Division of the NASA Science Mission Directorate, the National Science Foundation under Grant No. AST-1238877, the University of Maryland, and Eotvos Lorand University (ELTE).
Funding Information:
We thank Rachel Mandelbaum for useful comments on this manuscript and Jim Gunn for enlightening discussions. We also thank the anonymous referee for insightful comments that significantly improved the paper. The HSC collaboration includes the astronomical communities of Japan and Taiwan, and Princeton University. The HSC instrumentation and software were developed by the National Astronomical Observatory of Japan (NAOJ), the Kavli Institute for the Physics and Mathematics of the Universe (Kavli IPMU), the University of Tokyo, the High Energy Accelerator Research Organization (KEK), the Academia Sinica Institute for Astronomy and Astrophysics in Taiwan (ASIAA), and Princeton University. Funding was contributed by the FIRST program from Japanese Cabinet Office, the Ministry of Education, Culture, Sports, Science and Technology (MEXT), the Japan Society for the Promotion of Science (JSPS), Japan Science and Technology Agency (JST), the Toray Science Foundation, NAOJ, Kavli IPMU, KEK, ASIAA, and Princeton University. The Pan-STARRS1 Surveys (PS1) (Schlafly et al. 2012; Tonry et al. 2012; Magnier et al. 2013) have been made possible through contributions of the Institute for Astronomy, the University of Hawaii, the Pan-STARRS Project Office, the Max-Planck Society and its participating institutes, the Max Planck Institute for Astronomy, Heidelberg and the Max Planck Institute for Extraterrestrial Physics, Garching, The Johns Hopkins University, Durham University, the University of Edinburgh, Queen's University Belfast, the Harvard-Smithsonian Center for Astrophysics, the Las Cumbres Observatory Global Telescope Network Incorporated, the National CentralUniversity of Taiwan, the Space Telescope Science Institute, theNationalAeronautics and Space Administration underGrant No. NNX08AR22G issued through the Planetary Science Division of the NASA Science Mission Directorate, the National Science Foundation under Grant No. AST-1238877, the University of Maryland, and Eotvos Lorand University (ELTE). This paper makes use of software developed for the LSST. We thank the LSST Project for making their code available as free software at http://dm.lsst.org. Based in part on data collected at the Subaru Telescope and retrieved from the HSC data archive system, which is operated by the Subaru Telescope and Astronomy Data Center at National Astronomical Observatory of Japan.
Funding Information:
The HSC collaboration includes the astronomical communities of Japan and Taiwan, and Princeton University. The HSC instrumentation and software were developed by the National Astronomical Observatory of Japan (NAOJ), the Kavli Institute for the Physics and Mathematics of the Universe (Kavli IPMU), the University of Tokyo, the High Energy Accelerator Research Organization (KEK), the Academia Sinica Institute for Astronomy and Astrophysics in Taiwan (ASIAA), and Princeton University. Funding was contributed by the FIRST program from Japanese Cabinet Office, the Ministry of Education, Culture, Sports, Science and Technology (MEXT), the Japan Society for the Promotion of Science (JSPS), Japan Science and Technology Agency (JST), the Toray Science Foundation, NAOJ, Kavli IPMU, KEK, ASIAA, and Princeton University.
Publisher Copyright:
© 2018 The Author(s) Published by Oxford University Press on behalf of the Royal Astronomical Society.
PY - 2018/9/11
Y1 - 2018/9/11
N2 - We measure and model the wavelength dependence of the point spread function (PSF) in the Hyper Suprime-Cam Subaru Strategic Program survey. We find that PSF chromaticity is present in the redder stars that appear smaller than bluer stars in the g, r, and i bands at the 1-2 per cent level and in the z and y bands at the 0.1-0.2 per cent level. From the color dependence of the PSF, we fit a model between the monochromatic PSF size based on weighted second moments, R, and wavelength of the form R(λ) ∝ λ-b. We find values of b between 0.2 and 0.5, depending on the epoch and filter. This is consistent with the expectations of a turbulent atmosphere with an outer scale length of ~10-100 m, indicating that the atmosphere is dominating the chromaticity. In the best seeing data, we find that the optical system and detector also contribute some wavelength dependence. Meyers & Burchat showed that b must be measured to an accuracy of ~0.02 not to dominate the systematic error budget of the Large Synoptic Survey Telescope (LSST) weak lensing (WL) survey. Using simple image simulations, we find that b can be inferred with this accuracy in the r and i-bands for all positions in the LSST focal plane, assuming a stellar density of 1 star arcmin-2 and that the optical component of the PSF can be accurately modeled. Therefore, it is possible to correct for most, if not all, of the bias that the wavelength-dependent PSF will introduce into an LSST-like WL survey.
AB - We measure and model the wavelength dependence of the point spread function (PSF) in the Hyper Suprime-Cam Subaru Strategic Program survey. We find that PSF chromaticity is present in the redder stars that appear smaller than bluer stars in the g, r, and i bands at the 1-2 per cent level and in the z and y bands at the 0.1-0.2 per cent level. From the color dependence of the PSF, we fit a model between the monochromatic PSF size based on weighted second moments, R, and wavelength of the form R(λ) ∝ λ-b. We find values of b between 0.2 and 0.5, depending on the epoch and filter. This is consistent with the expectations of a turbulent atmosphere with an outer scale length of ~10-100 m, indicating that the atmosphere is dominating the chromaticity. In the best seeing data, we find that the optical system and detector also contribute some wavelength dependence. Meyers & Burchat showed that b must be measured to an accuracy of ~0.02 not to dominate the systematic error budget of the Large Synoptic Survey Telescope (LSST) weak lensing (WL) survey. Using simple image simulations, we find that b can be inferred with this accuracy in the r and i-bands for all positions in the LSST focal plane, assuming a stellar density of 1 star arcmin-2 and that the optical component of the PSF can be accurately modeled. Therefore, it is possible to correct for most, if not all, of the bias that the wavelength-dependent PSF will introduce into an LSST-like WL survey.
KW - Atmospheric effects
KW - Gravitational lensing: weak
KW - Instrumentation: detectors
KW - Methods: observational
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U2 - 10.1093/mnras/sty1636
DO - 10.1093/mnras/sty1636
M3 - Article
AN - SCOPUS:85050191175
SN - 0035-8711
VL - 479
SP - 1491
EP - 1504
JO - Monthly Notices of the Royal Astronomical Society
JF - Monthly Notices of the Royal Astronomical Society
IS - 2
ER -