__smbhome.uscs.susx.ac.uk_bw233_Desktop_SRO_SRO - Kathy Romer_Post-Easter 2018_sty787.pdf (1.38 MB)
Cross-correlation redshift calibration without spectroscopic calibration samples in DES science verification data
journal contribution
posted on 2023-06-09, 13:16 authored by C Davis, E Rozo, A Roodman, A Alarcon, R Cawthon, M Gatti, H Lin, R Miquel, E S Rykoff, M A Troxel, P Vielzeuf, Kathy RomerKathy Romer, the DES Collaboration andGalaxy cross-correlations with high-fidelity redshift samples hold the potential to precisely calibrate systematic photometric redshift uncertainties arising from the unavailability of complete and representative training and validation samples of galaxies. However, application of this technique in the Dark Energy Survey (DES) is hampered by the relatively low number density, small area, and modest redshift overlap between photometric and spectroscopic samples. We propose instead using photometric catalogues with reliable photometric redshifts for photo-z calibration via cross-correlations. We verify the viability of our proposal using redMaPPer clusters from the Sloan Digital Sky Survey (SDSS) to successfully recover the redshift distribution of SDSS spectroscopic galaxies. We demonstrate how to combine photo-z with cross-correlation data to calibrate photometric redshift biases while marginalizing over possible clustering bias evolution in either the calibration or unknown photometric samples. We apply our method to DES Science Verification (DES SV) data in order to constrain the photometric redshift distribution of a galaxy sample selected for weak lensing studies, constraining the mean of the tomographic redshift distributions to a statistical uncertainty of z ~ ±0.01. We forecast that our proposal can, in principle, control photometric redshift
Funding
University of Sussex Astronomy Consolidated Grant 2017-2020; G2050; STFC-SCIENCE AND TECHNOLOGY FACILITIES COUNCIL; ST/P000525/1
History
Publication status
- Published
File Version
- Published version
Journal
Monthly Notices of the Royal Astronomical SocietyISSN
0035-8711Publisher
Oxford University PressExternal DOI
Issue
2Volume
477Page range
2196-2208Department affiliated with
- Physics and Astronomy Publications
Full text available
- Yes
Peer reviewed?
- Yes
Legacy Posted Date
2018-05-15First Open Access (FOA) Date
2018-05-15First Compliant Deposit (FCD) Date
2018-05-14Usage metrics
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