COSMO-LYA
COSMO-LYA
About
Team
Collaborations
Funding
Publications
News
Outreach
Contact
Publications
3D Correlations in the Lyman-α Forest from Early DESI Data
We present the first measurements of Lyman-αα (Lyαα) forest correlations using early data from the Dark Energy Spectroscopic Instrument (DESI). We measure the auto-correlation of Lyαα absorption using 88,509 quasars at z>2z>2, and its cross-correlation with quasars using a further 147,899 tracer quasars at z≳1.77z≳1.77. Then, we fit these correlations using a 13-parameter model based on linear perturbation theory and find that it provides a good description of the data across a broad range of scales. We detect the BAO peak with a signal-to-noise ratio of 3.8σ3.8σ, and show that our measurements of the auto- and cross-correlations are fully-consistent with previous measurements by the Extended Baryon Oscillation Spectroscopic Survey (eBOSS). Even though we only use here a small fraction of the final DESI dataset, our uncertainties are only a factor of 1.7 larger than those from the final eBOSS measurement. We validate the existing analysis methods of Lyαα correlations in preparation for making a robust measurement of the BAO scale with the first year of DESI data.
C. Gordon
,
A. Cuceu
,
J. Chaves-Montero
,
A. Font-Ribera
,
et al
Aug 21, 2023
DOI
arXiv
The Lyman-alpha forest catalog from the Dark Energy Spectroscopic Instrument Early Data Release
This publication presents and validates the Lyman-alpha forest fluctuations in the first DESI data release. To accomplish this measurement, the continua of DESI quasars were fitted not only in the Lyman-alpha forest region but also in featureless regions to the right of the Lyman-alpha emission line, which were used for calibration.The image displays the observed flux (black) of a high-SNR DESI quasar. The different coloured lines show the expected flux for each of the regions (quasar continuum corrected by the mean absorption), for the Lyman-alpha forest region and the SIV, CIV and CIII calibration regions.For this publication, we followed the procedures designed for SDSS analyses and made necessary adaptations for the DESI pipeline. Additionally, we enhanced the weighting scheme, resulting in an improvement of over 20% in the precision of the correlation function measurement.
C. Ramírez-Pérez
,
I. Pérez-Ràfols
,
A. Font-Ribera
Jun 9, 2023
DOI
arXiv
A neural network emulator for the Lyman-α 1D flux power spectrum
The Lyman-α offers a unique avenue for studying the distribution of matter in the high redshift universe and extracting precise …
Laura Cabayol-Garcia
,
Jonás Chaves-Montero
,
Andreu Font-Ribera
,
Christian Pedersen
May 30, 2023
DOI
arXiv
New constraints on the expansion rate at redshift 2.3 from the Lyman-$α$ forest
We measure the expansion rate of the Universe at redshift z=2.3 from the anisotropy of Lyman-α (Lyα) forest correlations measured by …
Andrei Cuceu
,
Andreu Font-Ribera
,
Seshadri Nadathur
,
Benjamin Joachimi
,
Paul Martini
Sep 28, 2022
DOI
arXiv
The Alcock-Paczyński effect from Lyman-$α$ forest correlations: Analysis validation with synthetic data
The three-dimensional distribution of the Lyα forest has been extensively used to constrain cosmology through measurements of the …
Andrei Cuceu
,
Andreu Font-Ribera
,
Paul Martini
,
Benjamin Joachimi
,
Seshadri Nadathur
,
James Rich
,
Alma X. González-Morales
,
Hélion du Mas des Bourboux
,
James Farr
Sep 26, 2022
DOI
arXiv
Direct cosmological inference from three-dimensional correlations of the Lyman-$α$ forest
When performing cosmological inference, standard analyses of the Lyman-α (Lyα) three-dimensional correlation functions only consider …
Francesca Gerardi
,
Andrei Cuceu
,
Andreu Font-Ribera
,
Benjamin Joachimi
,
Pablo Lemos
Sep 22, 2022
DOI
arXiv
Compressing the cosmological information in one-dimensional correlations of the Lyman-$α$ forest
Observations of the Lyman-α (Lyα) forest from spectroscopic surveys such as BOSS/eBOSS, or the ongoing DESI, offer a unique window to …
Christian Pedersen
,
Andreu Font-Ribera
,
Nickolay Y. Gnedin
Sep 20, 2022
DOI
arXiv
The effect of quasar redshift errors on Lyman-$alpha$ forest correlation functions
Using synthetic Lyman-α forests from the Dark Energy Spectroscopic Instrument (DESI) survey, we present a study of the impact of errors …
Samantha Youles
,
Julian E Bautista
,
Andreu Font-Ribera
,
et al
May 13, 2022
DOI
arXiv
Non-linearities in the Lyman-$α$ forest and in its cross-correlation with dark matter halos
Three-dimensional correlations of the Lyman-α (Lyα) forest and cross correlations between the Lyα forest and quasars have been measured …
Jahmour J. Givans
,
Andreu Font-Ribera
,
Anže Slosar
,
Louise Seeyave
,
Christian Pedersen
,
Keir K. Rogers
,
Mathias Garny
,
Diego Blas
,
Vid Iršič
May 2, 2022
DOI
arXiv
CoLoRe: fast cosmological realisations over large volumes with multiple tracers
We present CoLoRe, a public software package to efficiently generate synthetic realisations of multiple cosmological surveys. CoLoRe …
César Ramírez-Pérez
,
Javier Sanchez
,
David Alonso
,
Andreu Font-Ribera
Nov 9, 2021
DOI
arXiv
»