HOD-Dependent Systematics in Emission Line Galaxies for the DESI 2024 BAO analysis
Abstract
The Dark Energy Spectroscopic Instrument (DESI) will provide precise measurements of Baryon Acoustic Oscillations (BAO) to constrain the expansion history of the Universe and set stringent constraints on dark energy. Therefore, precise control of the global error budget due to various systematic effects is required for the DESI 2024 BAO analysis. In this work, we focus on the robustness of the BAO analysis against the Halo Occupation Distribution (HOD) modeling for the Emission Line Galaxy (ELG) tracer. Based on a common dark matter simulation, our analysis relies on HOD mocks tuned to early DESI data, namely the One-Percent survey data. To build the mocks, we use several HOD models for the ELG tracer as well as extensions to the baseline HOD models. Among these extensions, we consider distinct recipes for galactic conformity and assembly bias. We perform two independent analyses in the Fourier space and in the configuration space. We recover the BAO signal from two-point measurements after performing reconstruction on our mocks. Additionally, we also apply the control variates technique to reduce sample variance noise. Our BAO analysis can recover the isotropic BAO parameter within 0.1\% and the Alcock Paczynski parameter within 0.3\%. Overall, we find that our systematic error due to the HOD dependence is below 0.17\%, with the Fourier space analysis being more robust against the HOD systematics. We conclude that our analysis pipeline is robust enough against the HOD systematics for the ELG tracer in the DESI 2024 BAO analysis.
Keywords
Cite
@article{arxiv.2404.03009,
title = {HOD-Dependent Systematics in Emission Line Galaxies for the DESI 2024 BAO analysis},
author = {C. Garcia-Quintero and J. Mena-Fernández and A. Rocher and S. Yuan and B. Hadzhiyska and O. Alves and M. Rashkovetskyi and H. Seo and N. Padmanabhan and S. Nadathur and C. Howlett and M. Ishak and L. Medina-Varela and P. McDonald and A. J. Ross and Y. Xie and X. Chen and A. Bera and J. Aguilar and S. Ahlen and U. Andrade and S. BenZvi and D. Brooks and E. Burtin and S. Chen and T. Claybaugh and S. Cole and A. de la Macorra and A. de Mattia and A. Dey and B. Dey and Z. Ding and P. Doel and K. Fanning and J. E. Forero-Romero and E. Gaztañaga and H. Gil-Marín and S. Gontcho A Gontcho and G. Gutierrez and J. Guy and C. Hahn and K. Honscheid and A. Kremin and M. Landriau and L. Le Guillou and M. E. Levi and M. Manera and P. Martini and A. Meisner and R. Miquel and J. Moustakas and E. Mueller and A. Muñoz-Gutiérrez and A. D. Myers and J. A. Newman and J. Nie and G. Niz and E. Paillas and N. Palanque-Delabrouille and W. J. Percival and C. Poppett and A. Pérez-Fernández and A. Rosado-Marin and G. Rossi and R. Ruggeri and E. Sanchez and D. Schlegel and M. Schubnell and D. Sprayberry and G. Tarlé and M. Vargas-Magaña and B. A. Weaver and J. Yu and H. Zhang and R. Zhou and H. Zou},
journal= {arXiv preprint arXiv:2404.03009},
year = {2025}
}
Comments
Supporting publication of DESI 2024 III: Baryon Acoustic Oscillations from Galaxies and Quasars