Spectroscopic Needs for Imaging Dark Energy Experiments: Photometric Redshift Training and Calibration

J. Newman; A. Abate; F. Abdalla; S. Allam; S. Allen; R. Ansari; S. Bailey; W. Barkhouse; T. Beers; M. Blanton; M. Brodwin; J. Brownstein; R. Brunner; M. Carrasco-Kind; J. Cervantes-Cota; E. Chisari; M. Colless; J. Comparat; J. Coupon; E. Cheu; C. Cunha; A. de la Macorra; I. Dell'Antonio; B. Frye; E. Gawiser; N. Gehrels; K. Grady; A. Hagen; P. Hall; A. Hearin; H. Hildebrandt; C. Hirata; S. Ho; K. Honscheid; D. Huterer; Z. Ivezic; J. -P. Kneib; J. Kruk; O. Lahav; R. Mandelbaum; J. Marshall; D. Matthews; B. Ménard; R. Miquel; M. Moniez; W. Moos; J. Moustakas; C. Papovich; J. Peacock; C. Park; J. Rhodes; J-S. Ricol; I. Sadeh; A. Slozar; S. Schmidt; D. Stern; T. Tyson; A. von der Linden; R. Wechsler; W. Wood-Vasey; A. Zentner

doi:10.1016/j.astropartphys.2014.06.007

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arXiv · 1309.5384

Spectroscopic Needs for Imaging Dark Energy Experiments: Photometric Redshift Training and Calibration

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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.

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J. Newman, A. Abate, F. Abdalla, S. Allam, S. Allen, R. Ansari, S. Bailey, W. Barkhouse, T. Beers, M. Blanton, M. Brodwin, J. Brownstein, R. Brunner, M. Carrasco-Kind, J. Cervantes-Cota, E. Chisari, M. Colless, J. Comparat, J. Coupon, E. Cheu, C. Cunha, A. de la Macorra, I. Dell'Antonio, B. Frye, E. Gawiser, N. Gehrels, K. Grady, A. Hagen, P. Hall, A. Hearin, H. Hildebrandt, C. Hirata, S. Ho, K. Honscheid, D. Huterer, Z. Ivezic, J. -P. Kneib, J. Kruk, O. Lahav, R. Mandelbaum, J. Marshall, D. Matthews, B. Ménard, R. Miquel, M. Moniez, W. Moos, J. Moustakas, C. Papovich, J. Peacock, C. Park, J. Rhodes, J-S. Ricol, I. Sadeh, A. Slozar, S. Schmidt, D. Stern, T. Tyson, A. von der Linden, R. Wechsler, W. Wood-Vasey, A. Zentner. 2013-09-20. Spectroscopic Needs for Imaging Dark Energy Experiments: Photometric Redshift Training and Calibration. https://doi.org/10.1016/j.astropartphys.2014.06.007

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