Overview of the DESI Milky Way Survey
Abstract
We describe the Milky Way Survey (MWS) that will be undertaken with the Dark Energy Spectroscopic Instrument (DESI) on the Mayall 4m telescope at the Kitt Peak National Observatory. Over the next 5 yr DESI MWS will observe approximately seven million stars at Galactic latitudes |b|>20 degrees, with an inclusive target selection scheme focused on the thick disk and stellar halo. MWS will also include several high-completeness samples of rare stellar types, including white dwarfs, low-mass stars within 100pc of the Sun, and horizontal branch stars. We summarize the potential of DESI to advance understanding of Galactic structure and stellar evolution. We introduce the final definitions of the main MWS target classes and estimate the number of stars in each class that will be observed. We describe our pipelines for deriving radial velocities, atmospheric parameters, and chemical abundances. We use ~500,000 spectra of unique stellar targets from the DESI Survey Validation program (SV) to demonstrate that our pipelines can measure radial velocities to ~1 km/s and [Fe/H] accurate to ~0.2 dex for typical stars in our main sample. We find the stellar parameter distributions from ~100 sq. deg of SV observations with >90% completeness on our main sample are in good agreement with expectations from mock catalogs and previous surveys.
Keywords
Cite
@article{arxiv.2208.08514,
title = {Overview of the DESI Milky Way Survey},
author = {Andrew P. Cooper and Sergey E. Koposov and Carlos Allende Prieto and Christopher J. Manser and Namitha Kizhuprakkat and Adam D. Myers and Arjun Dey and Boris T. Gaensicke and Ting S. Li and Constance Rockosi and Monica Valluri and Joan Najita and Alis Deason and Anand Raichoor and Mei-Yu Wang and Yuan-Sen Ting and Bokyoung Kim and Andreia Carrillo and Wenting Wang and Leandro Beraldo e Silva and Jiwon Jesse Han and Jiani Ding and Miguel Sanchez-Conde and Jessica N. Aguilar and Steven Ahlen and Stephen Bailey and Vasily Belokurov and David Brooks and Katia Cunha and Kyle Dawson and Axel de la Macorra and Peter Doel and Daniel J. Eisenstein and Parker Fagrelius and Kevin Fanning and Andreu Font-Ribera and Jaime E. Forero-Romero and Enrique Gaztanaga and Satya Gontcho A Gontcho and Julien Guy and Klaus Honscheid and Robert Kehoe and Theodore Kisner and Anthony Kremin and Martin Landriau and Michael E. Levi and Paul Martini and Aaron M. Meisner and Ramon Miquel and John Moustakas and Jundan Nie and Nathalie Palanque-Delabrouille and Will J. Percival and Claire Poppett and Francisco Prada and Nabeel Rehemtulla and Edward Schlafly and David Schlegel and Michael Schubnell and Ray M. Sharples and Gregory Tarle and Risa H. Wechsler and David H. Weinberg and Zhimin Zhou and Hu Zou},
journal= {arXiv preprint arXiv:2208.08514},
year = {2023}
}
Comments
Accepted for publication in ApJ, 44 pages, 25 figures, 4 tables, one of a suite of 8 papers detailing targeting for DESI; v2 added links to data shown in figures, added citations to other DESI papers, corrected author list and minor typos; v3 fixed minor errors in Fig. 6 and clarified associated text; v4 updated to include minor changes in response to review