The effects of continuum fitting on Lyman-α forest correlations
Abstract Correlations of fluctuations of the flux in Lyman-α forests of high-redshift quasars have been observed by the Baryonic Acoustic Oscillation Spectroscopy Survey (BOSS) and the Dark Energy Spectroscopy Instrument (DESI) survey where they have revealed the effects of baryon acoustic oscillations (BAO). In order to fit the correlation functions to a physical model and thereby constrain cosmological parameters, it is necessary to take into account the effects of fitting the observed spectra to a template about which the fluctuations are measured. In this paper we use mock spectra to test the distortion matrix technique that has been used since the final BOSS data release to appropriately distort the models. We show that while percent-level effects on the derived forest bias parameters may be present, the technique works sufficiently well that the determination of the BAO peak position is not affected at the percent level. We introduce modifications in the technique used by DESI that were not in the original applications and suggest further possibilities for improvements.
Authors
- D. Kirkby (ORCID: https://orcid.org/0000-0002-8828-5463)
- C. Ravoux (ORCID: https://orcid.org/0000-0002-3500-6635)
- Nicolás G. Busca
- Julian Bautista (ORCID: https://orcid.org/0000-0002-9885-3989)
- D. Brooks (ORCID: https://orcid.org/0000-0002-8458-5047)
- Rongpu Zhou (ORCID: https://orcid.org/0000-0001-5381-4372)
- D. Schlegel
- Julianna Stermer
- N. Palanque‐Delabrouille (ORCID: https://orcid.org/0000-0003-3188-784X)
- S. Nadathur (ORCID: https://orcid.org/0000-0001-9070-3102)
- H. K. Herrera-Alcantar (ORCID: https://orcid.org/0000-0002-9136-9609)
- J. Ereza (ORCID: https://orcid.org/0000-0002-0194-4017)
- Gregory Tarlé (ORCID: https://orcid.org/0000-0003-1704-0781)
- Andreu Font-Ribera (ORCID: https://orcid.org/0000-0002-3033-7312)
- Laurent Le Guillou (ORCID: https://orcid.org/0000-0001-7178-8868)
- Ignasi Pérez-Ràfols (ORCID: https://orcid.org/0000-0001-6979-0125)
- Axel de la Macorra (ORCID: https://orcid.org/0000-0002-1769-1640)
- Simone Ferraro (ORCID: https://orcid.org/0000-0003-4992-7854)
- S. Ahlen
- M. Landriau
- J. Guy (ORCID: https://orcid.org/0000-0001-9822-6793)
- Eusebio Sanchez (ORCID: https://orcid.org/0000-0002-9646-8198)
- J. Aguilar
- ENRIQUE GAZTAÑAGA (ORCID: https://orcid.org/0000-0001-9632-0815)
- Andrei Cuceu (ORCID: https://orcid.org/0000-0002-2169-0595)
- Joseph Harry Silber (ORCID: https://orcid.org/0000-0002-3461-0320)
- G. Gutierrez (ORCID: https://orcid.org/0000-0003-0825-0517)
- J. E. Forero-Romero (ORCID: https://orcid.org/0000-0002-2890-3725)
- Davide Bianchi (ORCID: https://orcid.org/0000-0001-9712-0006)
- R. Miquel (ORCID: https://orcid.org/0000-0002-6610-4836)
- H. Zou
- Mustapha Ishak (ORCID: https://orcid.org/0000-0002-6024-466X)
- Hee‐Jong Seo (ORCID: https://orcid.org/0000-0002-6588-3508)
- Christophe Balland
- T. Claybaugh (ORCID: https://orcid.org/0000-0002-5024-6987)
- Graziano Rossi
- P. Doel
- J. Rich (ORCID: https://orcid.org/0009-0003-2777-9317)
- B. A. Weaver
- C. Magneville
- Francisco Prada (ORCID: https://orcid.org/0000-0001-7145-8674)
- K. Fanning (ORCID: https://orcid.org/0000-0003-2371-3356)
- R. Kehoe (ORCID: https://orcid.org/0000-0002-6024-466X)
- D. Sprayberry
- C. Gordon (ORCID: https://orcid.org/0000-0003-2561-5733)
Institutions
- Boston University (US)
- Institució Catalana de Recerca i Estudis Avançats (ES)
- Universidad Complutense de Madrid (ES)
- Centre National de la Recherche Scientifique (FR)
- Fermi National Accelerator Laboratory (US)
- Institute of Space Sciences (ES)
- Lawrence Berkeley National Laboratory (US)
- Universidad de Los Andes (CO)
- The University of Texas at Dallas (US)
- Southern Methodist University (US)
- Institute for High Energy Physics (ES)
- University of Milan (IT)
- Université Clermont Auvergne (FR)
- University of California, Irvine (US)
- Aix-Marseille Université (FR)
- Commissariat à l'Énergie Atomique et aux Énergies Alternatives (FR)
- Université Paris-Saclay (FR)
- University of Michigan (US)
- Institut d'Astrophysique de Paris (FR)
- Brera Astronomical Observatory (IT)
- Sejong University (KR)
- Sorbonne Université (FR)
- Institut d'Estudis Espacials de Catalunya (ES)
- Centre de physique des particules de Marseille (FR)
- Laboratoire de Physique de Clermont Auvergne (FR)
- Laboratoire de Physique Nucléaire et de Hautes Énergies (FR)
- Ohio University (US)
- CEA Paris-Saclay (FR)
- Institut National de Physique Nucléaire et de Physique des Particules (FR)
- Community Science and Data Center (US)
- Instituto de Astrofísica de Andalucía (ES)
- National Astronomical Observatories (CN)
- Institut de Recherche sur les Lois Fondamentales de l'Univers (FR)
- Centro de Investigaciones Energéticas, Medioambientales y Tecnológicas (ES)
- University College London (GB)
- The Ohio State University (US)
- University of Portsmouth (GB)
- Michigan State University (US)
- Universidad Nacional Autónoma de México (MX)
- University of California, Berkeley (US)
- Universitat Politècnica de Catalunya (ES)
Publication Details
- Journal
- Journal of Cosmology and Astroparticle Physics
- Published
- 2025-09-01
- DOI
- https://doi.org/10.1088/1475-7516/2025/09/020
- Citations
- 2
- Primary Topic
- Galaxies: Formation, Evolution, Phenomena
- Type
- article
- Field-Weighted Citation Impact
- 2.31
Funders
- National Science Foundation
- U.S. Department of Energy
- Gordon and Betty Moore Foundation
- Ministerio de Ciencia, Innovación y Universidades
- Centres de Recerca de Catalunya
- European Commission
- Generalitat de Catalunya
- Ministerio de Ciencia e Innovación
- Commissariat à l'Énergie Atomique et aux Énergies Alternatives
- Institut de Física d'Altes Energies
- Office of Science
- HORIZON EUROPE Framework Programme
- Science and Technology Facilities Council
- Agencia Estatal de Investigación
- Division of Astronomical Sciences