The Target-selection Pipeline for the Dark Energy Spectroscopic Instrument
Abstract
In 2021 May, the Dark Energy Spectroscopic Instrument (DESI) began a 5 yr survey of approximately 50 million total extragalactic and Galactic targets. The primary DESI dark-time targets are emission line galaxies (ELGs), luminous red galaxies (LRGs) and quasars (QSOs). In bright time, DESI will focus on two surveys known as the Bright Galaxy Survey (BGS) and the Milky Way Survey (MWS). DESI also observes a selection of "secondary" targets for bespoke science goals. This paper gives an overview of the publicly available pipeline (desitarget) used to process targets for DESI observations. Highlights include details of the different DESI survey targeting phases, the targeting ID (TARGETID) used to define unique targets, the bitmasks used to indicate a particular type of target, the data model and structure of DESI targeting files, and examples of how to access and use the desitarget code base. This paper will also describe "supporting" DESI target classes, such as standard stars, sky locations, and random catalogs that mimic the angular selection function of DESI targets. The DESI target selection pipeline is complex and sizable; this paper attempts to summarize the most salient information required to understand and work with DESI targeting data.
Keywords
Cite
@article{arxiv.2208.08518,
title = {The Target-selection Pipeline for the Dark Energy Spectroscopic Instrument},
author = {Adam D. Myers and John Moustakas and Stephen Bailey and Benjamin A. Weaver and Andrew P. Cooper and Jaime E. Forero-Romero and Bela Abolfathi and David M. Alexander and David Brooks and Edmond Chaussidon and Chia-Hsun Chuang and Kyle Dawson and Arjun Dey and Biprateep Dey and Govinda Dhungana and Peter Doel and Kevin Fanning and Enrique Gaztañaga and Satya Gontcho A Gontcho and Alma X. Gonzalez-Morales and ChangHoon Hahn and Hiram K. Herrera-Alcantar and Klaus Honscheid and Mustapha Ishak and Tanveer Karim and David Kirkby and Theodore Kisner and Sergey E. Koposov and Anthony Kremin and Ting-Wen Lan and Martin Landriau and Dustin Lang and Michael E. Levi and Christophe Magneville and Lucas Napolitano and Paul Martini and Aaron Meisner and Jeffrey A. Newman and Nathalie Palanque-Delabrouille and Will Percival and Claire Poppett and Francisco Prada and Anand Raichoor and Ashley J. Ross and Edward F. Schlafly and David Schlegel and Michael Schubnell and Ting Tan and Gregory Tarle and Michael J. Wilson and Christophe Yèche and Rongpu Zhou and Zhimin Zhou and Hu Zou},
journal= {arXiv preprint arXiv:2208.08518},
year = {2023}
}
Comments
AJ, accepted, 27 pages, 4 figures, 10 tables, one of a suite of 8 papers detailing targeting for DESI. Minor textual updates to better match the final, accepted version. Also added two missing co-authors