First Detection of the BAO Signal from Early DESI Data
Abstract
We present the first detection of the baryon acoustic oscillations (BAO) signal obtained using unblinded data collected during the initial two months of operations of the Stage-IV ground-based Dark Energy Spectroscopic Instrument (DESI). From a selected sample of 261,291 Luminous Red Galaxies spanning the redshift interval 0.4 < z < 1.1 and covering 1651 square degrees with a 57.9% completeness level, we report a ~5 sigma level BAO detection and the measurement of the BAO location at a precision of 1.7%. Using a Bright Galaxy Sample of 109,523 galaxies in the redshift range 0.1 < z < 0.5, over 3677 square degrees with a 50.0% completeness, we also detect the BAO feature at ~3 sigma significance with a 2.6% precision. These first BAO measurements represent an important milestone, acting as a quality control on the optimal performance of the complex robotically-actuated, fiber-fed DESI spectrograph, as well as an early validation of the DESI spectroscopic pipeline and data management system. Based on these first promising results, we forecast that DESI is on target to achieve a high-significance BAO detection at sub-percent precision with the completed 5-year survey data, meeting the top-level science requirements on BAO measurements. This exquisite level of precision will set new standards in cosmology and confirm DESI as the most competitive BAO experiment for the remainder of this decade.
Keywords
Cite
@article{arxiv.2304.08427,
title = {First Detection of the BAO Signal from Early DESI Data},
author = {Jeongin Moon and David Valcin and Michael Rashkovetskyi and Christoph Saulder and Jessica Nicole Aguilar and Steven Ahlen and Shadab Alam and Stephen Bailey and Charles Baltay and Robert Blum and David Brooks and Etienne Burtin and Edmond Chaussidon and Kyle Dawson and Axel de la Macorra and Arnaud de Mattia and Govinda Dhungana and Daniel Eisenstein and Brenna Flaugher and Andreu Font-Ribera and Jaime E. Forero-Romero and Cristhian Garcia-Quintero and Satya Gontcho A Gontcho and Julien Guy and Malik Muhammad Sikandar Hanif and Klaus Honscheid and Mustapha Ishak and Robert Kehoe and Sumi Kim and Theodore Kisner and Anthony Kremin and Martin Landriau and Laurent Le Guillou and Michael Levi and Marc Manera and Paul Martini and Patrick McDonald and Aaron Meisner and Ramon Miquel and John Moustakas and Adam Myers and Seshadri Nadathur and Richard Neveux and Jeffrey A. Newman and Jundan Nie and Nikhil Padmanabhan and Nathalie Palanque-Delabrouille and Will Percival and Alejandro Pérez Fernández and Claire Poppett and Francisco Prada and Anand Raichoor and Ashley J. Ross and Graziano Rossi and Lado Samushia and David Schlegel and Hee-Jong Seo and Gregory Tarlé and Mariana Vargas Magana and Andrei Variu and Benjamin Alan Weaver and Martin J. White and Christophe Yèche and Sihan Yuan and Cheng Zhao and Rongpu Zhou and Zhimin Zhou and Hu Zou},
journal= {arXiv preprint arXiv:2304.08427},
year = {2025}
}
Comments
17 pages, 10 figures, 4 tables. MNRAS, 525, 5406. Author accepted manuscript matching the published version