Karaçayll, NG;
Martini, P;
Guy, J;
Ravoux, C;
Abdul Karim, ML;
Armengaud, E;
Walther, M;
... Zhou, Z; + view all
(2024)
Optimal 1D Ly α forest power spectrum estimation – III. DESI early data.
Monthly Notices of the Royal Astronomical Society
, 528
(3)
pp. 3941-3963.
10.1093/mnras/stae171.
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Abstract
The 1D power spectrum P1D of the Ly α forest provides important information about cosmological and astrophysical parameters, including constraints on warm dark matter models, the sum of the masses of the three neutrino species, and the thermal state of the intergalactic medium. We present the first measurement of P1D with the quadratic maximum likelihood estimator (QMLE) from the Dark Energy Spectroscopic Instrument (DESI) survey early data sample. This early sample of 54 600 quasars is already comparable in size to the largest previous studies, and we conduct a thorough investigation of numerous instrumental and analysis systematic errors to evaluate their impact on DESI data with QMLE. We demonstrate the excellent performance of the spectroscopic pipeline noise estimation and the impressive accuracy of the spectrograph resolution matrix with 2D image simulations of raw DESI images that we processed with the DESI spectroscopic pipeline. We also study metal line contamination and noise calibration systematics with quasar spectra on the red side of the Ly α emission line. In a companion paper, we present a similar analysis based on the Fast Fourier Transform estimate of the power spectrum. We conclude with a comparison of these two approaches and discuss the key sources of systematic error that we need to address with the upcoming DESI Year 1 analysis.
| Type: | Article |
|---|---|
| Title: | Optimal 1D Ly α forest power spectrum estimation – III. DESI early data |
| Open access status: | An open access version is available from UCL Discovery |
| DOI: | 10.1093/mnras/stae171 |
| Publisher version: | http://dx.doi.org/10.1093/mnras/stae171 |
| Language: | English |
| Additional information: | Copyright © 2024 The Author(s). Published by Oxford University Press on behalf of Royal Astronomical Society. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (https://creativecommons.org/licenses/by/4.0/), which permits unrestricted reuse, distribution, and reproduction in any medium, provided the original work is properly cited. |
| Keywords: | Methods: data analysis, intergalactic medium, quasars: absorption lines |
| UCL classification: | UCL UCL > Provost and Vice Provost Offices > UCL BEAMS UCL > Provost and Vice Provost Offices > UCL BEAMS > Faculty of Maths and Physical Sciences UCL > Provost and Vice Provost Offices > UCL BEAMS > Faculty of Maths and Physical Sciences > Dept of Physics and Astronomy |
| URI: | https://discovery.ucl.ac.uk/id/eprint/10187509 |
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