Self Calibrated Galaxy Groups from the DESI DR1 Bright Galaxy Survey
Abstract
We present a galaxy group catalog built from Data Release 1 of the Dark Energy Spectroscopic Instrument (DESI) Bright Galaxy Survey, using the Self Calibrated Group Finder. The algorithm uses clustering data from the observed sample to calibrate the Group Finder's free parameters, rather than simulations. The catalog contains 2,229,741 galaxies from ~$2680$ deg2 of sky with 3-pass coverage and r-band fluxes lt 19.5. The catalog classifies all galaxies in the flux-limited sample as centrals or satellites and estimates host dark matter halo masses. We show the satellite fraction fsat, luminosity halo mass relation, stellar halo mass relation and halo occupation distributions (HODs) from the catalog. We find these non-parametric HODs can be fit by standard HOD models, with satellite power-law index α values around 0.75 for star-forming galaxies and around 1.1 for quiescent objects. In agreement with recent results, we find that the quenched fraction of central galaxies depends mostly on halo mass and is nearly independent of central galaxy stellar mass for galaxies more massive than 1010.3 M⊙ h−1 and halos more massive than 1012.2 M⊙ h−1. In an appendix, we introduce a new Hybrid Nearest Neighbor (HNN) technique to mitigate systematics from fiber incompleteness. HNN uses photometric redshifts and multiple on-sky neighbors to assign redshifts to unobserved targets. Calibrated on DESI Survey Validation 3 data, our technique yields correct redshifts ∼ 50% of the time and produces unbiased halo occupation statistics.
Related
- Environmental dependence of galaxy properties in the DESI DR1 Bright Galaxy Survey: Star formation, morphology, and AGN activity at z < 0.55
- How bright can a galaxy be? Extreme value predictions for high-redshift survey observables
- Precision kinematic Sunyaev-Zel’dovich measurements across halo mass and redshift with DESI DR2 and ACT DR6. II. Bright galaxy survey and emission-line galaxies
- A Sample of 459 Galaxy Groups Identified from the FAST All Sky HI Survey DR2
- OH Line Detections in Southern Galaxies of the IRAS Revised Bright Galaxy Sample
BibTeX
@misc{williams2026self,
title = {{Self Calibrated Galaxy Groups from the DESI DR1 Bright Galaxy Survey}},
author = {Ian Williams and Jeremy Tinker and Kai Wang and Jessica Nicole Aguilar and Steven Ahlen and Florian Beutler and Davide Bianchi and David Brooks and Aurelio Carnero Rosell and Francisco Javier Castander and Todd Claybaugh and Shaun Cole and Axel de la Macorra and Jaime E Forero-Romero and Enrique Gaztañaga and Satya Gontcho A. Gontcho and Gaston Gutierrez and Changhoon Hahn and Mustapha Ishak and Stephanie Juneau and Robert Kehoe and Anthony Kremin and Claire Lamman and Martin Landriau and Laurent Le Guillou and Alexie Leauthaud and Marc Manera and Aaron Meisner and Ramon Miquel and John Moustakas and Seshadri Nadathur and Enrique Paillas and Will Percival and Francisco Prada and Ignasi Pérez-Ràfols and Corentin Ravoux and Ashley J Ross and Graziano Rossi and Rossana Ruggeri and Lado Samushia and Eusebio Sanchez and Christoph Saulder and David Schlegel and Joseph Harry Silber and Małgorzata Siudek and Gregory Tarlé and Rajeev Vaisakh and Benjamin Alan Weaver},
howpublished = {HAL},
year = {2026},
month = oct,
doi = {10.48550/arxiv.2610.20919},
eprint = {2610.20919},
archivePrefix = {arXiv},
url = {https://hal.science/hal-05828740v1},
note = {CC BY 4.0},
}
RIS
TY - UNPB
TI - Self Calibrated Galaxy Groups from the DESI DR1 Bright Galaxy Survey
AU - Ian Williams
AU - Jeremy Tinker
AU - Kai Wang
AU - Jessica Nicole Aguilar
AU - Steven Ahlen
AU - Florian Beutler
AU - Davide Bianchi
AU - David Brooks
AU - Aurelio Carnero Rosell
AU - Francisco Javier Castander
AU - Todd Claybaugh
AU - Shaun Cole
AU - Axel de la Macorra
AU - Jaime E Forero-Romero
AU - Enrique Gaztañaga
AU - Satya Gontcho A. Gontcho
AU - Gaston Gutierrez
AU - Changhoon Hahn
AU - Mustapha Ishak
AU - Stephanie Juneau
AU - Robert Kehoe
AU - Anthony Kremin
AU - Claire Lamman
AU - Martin Landriau
AU - Laurent Le Guillou
AU - Alexie Leauthaud
AU - Marc Manera
AU - Aaron Meisner
AU - Ramon Miquel
AU - John Moustakas
AU - Seshadri Nadathur
AU - Enrique Paillas
AU - Will Percival
AU - Francisco Prada
AU - Ignasi Pérez-Ràfols
AU - Corentin Ravoux
AU - Ashley J Ross
AU - Graziano Rossi
AU - Rossana Ruggeri
AU - Lado Samushia
AU - Eusebio Sanchez
AU - Christoph Saulder
AU - David Schlegel
AU - Joseph Harry Silber
AU - Małgorzata Siudek
AU - Gregory Tarlé
AU - Rajeev Vaisakh
AU - Benjamin Alan Weaver
PY - 2026
DA - 2026/10/14
PB - HAL
DO - 10.48550/arxiv.2610.20919
UR - https://hal.science/hal-05828740v1
AB - We present a galaxy group catalog built from Data Release 1 of the Dark Energy Spectroscopic Instrument (DESI) Bright Galaxy Survey, using the Self Calibrated Group Finder. The algorithm uses clustering data from the observed sample to calibrate the Group Finder's free parameters, rather than simulations. The catalog contains 2,229,741 galaxies from ~$2680$ deg^2 of sky with 3-pass coverage and r-band fluxes lt 19.5. The catalog classifies all galaxies in the flux-limited sample as centrals or satellites and estimates host dark matter halo masses. We show the satellite fraction f_sat, luminosity halo mass relation, stellar halo mass relation and halo occupation distributions (HODs) from the catalog. We find these non-parametric HODs can be fit by standard HOD models, with satellite power-law index α values around 0.75 for star-forming galaxies and around 1.1 for quiescent objects. In agreement with recent results, we find that the quenched fraction of central galaxies depends mostly on halo mass and is nearly independent of central galaxy stellar mass for galaxies more massive than 10^10.3 M_⊙ h^−1 and halos more massive than 10^12.2 M_⊙ h^−1. In an appendix, we introduce a new Hybrid Nearest Neighbor (HNN) technique to mitigate systematics from fiber incompleteness. HNN uses photometric redshifts and multiple on-sky neighbors to assign redshifts to unobserved targets. Calibrated on DESI Survey Validation 3 data, our technique yields correct redshifts ∼ 50% of the time and produces unbiased halo occupation statistics.
ER -