Spectroscopic Needs for Imaging Dark Energy Experiments: Photometric Redshift Training and Calibration
Abstract
Large sets of objects with spectroscopic redshift measurements will be needed for imaging dark energy experiments to achieve their full potential, serving two goals:_training_, i.e., the use of objects with known redshift to develop and optimize photometric redshift algorithms; and_calibration_, i.e., the characterization of moments of redshift (or photo-z error) distributions. Better training makes cosmological constraints from a given experiment stronger, while highly-accurate calibration is needed for photo-z systematics not to dominate errors. In this white paper, we investigate the required scope of spectroscopic datasets which can serve both these purposes for ongoing and next-generation dark energy experiments, as well as the time required to obtain such data with instruments available in the next decade. Large time allocations on kilo-object spectrographs will be necessary, ideally augmented by infrared spectroscopy from space. Alternatively, precision calibrations could be obtained by measuring cross-correlation statistics using samples of bright objects from a large baryon acoustic oscillation experiment such as DESI. We also summarize the additional work on photometric redshift methods needed to prepare for ongoing and future dark energy experiments.
Keywords
Cite
@article{arxiv.1309.5384,
title = {Spectroscopic Needs for Imaging Dark Energy Experiments: Photometric Redshift Training and Calibration},
author = {J. Newman and A. Abate and F. Abdalla and S. Allam and S. Allen and R. Ansari and S. Bailey and W. Barkhouse and T. Beers and M. Blanton and M. Brodwin and J. Brownstein and R. Brunner and M. Carrasco-Kind and J. Cervantes-Cota and E. Chisari and M. Colless and J. Comparat and J. Coupon and E. Cheu and C. Cunha and A. de la Macorra and I. Dell'Antonio and B. Frye and E. Gawiser and N. Gehrels and K. Grady and A. Hagen and P. Hall and A. Hearin and H. Hildebrandt and C. Hirata and S. Ho and K. Honscheid and D. Huterer and Z. Ivezic and J. -P. Kneib and J. Kruk and O. Lahav and R. Mandelbaum and J. Marshall and D. Matthews and B. Ménard and R. Miquel and M. Moniez and W. Moos and J. Moustakas and C. Papovich and J. Peacock and C. Park and J. Rhodes and J-S. Ricol and I. Sadeh and A. Slozar and S. Schmidt and D. Stern and T. Tyson and A. von der Linden and R. Wechsler and W. Wood-Vasey and A. Zentner},
journal= {arXiv preprint arXiv:1309.5384},
year = {2016}
}
Comments
White paper for the "Dark Energy and CMB" working group for the American Physical Society's Division of Particles and Fields long-term planning exercise ("Snowmass")