Year: 2026
Type: preprint
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 ~$2680$ 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 $f_{\rm sat}$, 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 $10^{10.3}$ $M_\odot h^{-1}$ and halos more massive than $10^{12.2}$ $M_\odot h^{-1}$. 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 $\sim 50\%$ of the time and produces unbiased halo occupation statistics.
Source: arXiv (Cornell University)
Authors: Williams, I., Tinker, J., Wang, K., Aguilar, J., Ahlen, S., Beutler, F., Bianchi, D., Brooks, D., Rosell, A. Carnero, Castander, F. J., Claybaugh, T., Cole, S., de la Macorra, A., Forero-Romero, J. E., Gaztanaga, E., Gontcho, S. Gontcho A, Gutierrez, G., Hahn, C., Ishak, M., Juneau, S., Kehoe, R., Kremin, A., Lamman, C., Landriau, M., Guillou, L. Le, Leauthaud, A., Manera, M., Meisner, A., Miquel, R., Moustakas, J., Nadathur, S., Paillas, E., Percival, W. J., Prada, F., Perez-Rafols, I., Ravoux, C., Ross, A. J., Rossi, G., Ruggeri, R., Samushia, L., Sanchez, E., Saulder, C., Schlegel, D., Silber, J., Siudek, M., Tarle, G., Vaisakh, R., Weaver, B. A.
Institutions: New York University, Durham University, Lawrence Berkeley National Laboratory, Royal Observatory, University of Edinburgh, University College London, Universidad de La Laguna, Instituto de Astrofísica de Canarias, Institute of Space Sciences, Institut d'Estudis Espacials de Catalunya, Universidad Nacional Autónoma de México, The University of Texas at Austin, The University of Texas at Dallas, Southern Methodist University, The Ohio State University, University of Siena, Institució Catalana de Recerca i Estudis Avançats, University of Waterloo, Institute for High Energy Physics, Barcelona Institute of Science and Technology, Universidad Diego Portales, Universitat Politècnica de Catalunya, Sejong University, Centro de Investigaciones Energéticas, Medioambientales y Tecnológicas, Max Planck Institute for Extraterrestrial Physics, University of Michigan, NSF NOIRLab
Language: English
Subfield: Astronomy and Astrophysics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: green
Funders: National Science Foundation, U.S. Department of Energy, Gordon and Betty Moore Foundation, Ministerio de Ciencia, Innovación y Universidades, Commissariat à l'Énergie Atomique et aux Énergies Alternatives, Office of Science, Science and Technology Facilities Council, Agencia Estatal de Investigación, Division of Astronomical Sciences
Awards: G1044631029, G1105844351, G1286236842, G1813527838, G1863003419, G3452655474, The Dark Matter Halo Finder, G419881185, G42916606, G4501827968, G491712853, G498139845, G5635532810, G593054264, G6652958823, G6876926712, Management and Operations of the National Optical Astronomy Observatory, G7395345766, G7805626310, G7863371703, G8497050386, G8667377315
OpenAlex ID: W7222644947