The construction of large-scale structure catalogs for the Dark Energy Spectroscopic Instrument
Ashley J. Ross, J. Aguilar, S. P. Ahlen, Shadab Alam, Abhijeet Anand, S. Bailey, D. Bianchi, S. Brieden, David J. Brooks, E. Burtin, A. Carnero Rosell, E. Chaussidon, T. Claybaugh, Shaun Cole, Kyle Dawson, Axel de la Macorra, Arnaud de Mattia, Arjun Dey, Biprateep Dey, Peter Doel, K. Fanning, S Ferraro, J. Ereza, Andreu Font-Ribera, J. E. Forero-Romero, E. Gaztañaga, Héctor Gil-Marín, Satya Gontcho A Gontcho, A.X Gonzalez-Morales, J. Guy, ChangHoon Hahn, Sven Heydenreich, Klaus Honscheid, Cullan Howlett, Mustapha Ishak, Tariq Karim, D. Kirkby, Theodore Kisner, Hui Kong, Anthony Kremin, Alex Krolewski, Andrew Lambert, Martin Landriau, J. Lasker, L. Le Guillou, M. E. Levi, Marc Manera, Paul Martini, P. McDonald, Aaron Meisner, R. Miquel, J. Moon, John Moustakas, A. Muñoz-Gutiérrez, Adam D. Myers, S. Nadathur, L. Napolitano, Jeffrey A. Newman, Jundan Nie, Gustavo Niz, N. Palanque-Delabrouille, Will J. Percival, Claire Poppett, Francisco Prada, Anand Raichoor, C. Ravoux, Mehdi Rezaie, A Rosado-Marin, Graziano Rossi, Lado Samushia, E. Sánchez, Edward F. Schlafly, David J. Schlegel, Hee‐Jong Seo, A. G. Smith, David Sprayberry, G. Tarlé, D. Valcin, M. Vargas-Magaña, B. A. Weaver, M.J. Wilson, Jiaxi Yu, Pauline Zarrouk, Cheng Zhao, Rongpu Zhou, Hu Zou
Abstract
Abstract We present the technical details on how large-scale structure (LSS) catalogs are constructed from redshifts measured from spectra observed by the Dark Energy Spectroscopic Instrument (DESI). The LSS catalogs provide the information needed to determine the relative number density of DESI tracers as a function of redshift and celestial coordinates and, e.g., determine clustering statistics. We produce catalogs that are weighted subsamples of the observed data, each matched to a weighted `random' catalog that forms an unclustered sampling of the probability density that DESI could have observed those data at each location. Precise knowledge of the DESI observing history and associated hardware performance allows for a determination of the DESI footprint and the number of times DESI has covered it at sub-arcsecond level precision. This enables the completeness of any DESI sample to be modeled at this same resolution. The pipeline developed to create LSS catalogs has been designed to easily allow robustness tests and enable future improvements. We describe how it allows ongoing work improving the match between galaxy and random catalogs, such as including further information when assigning redshifts to randoms, accounting for fluctuations in target density, accounting for variation in the redshift success rate, and accommodating blinding schemes.