SIMPLE: Simple Intensity Map Producer for Line Emission

We present the Simple Intensity Map Producer for Line Emission ( Simple ), a public code for quickly simulating mock line-intensity maps, and an analytical framework for modeling intensity maps including observational effects. Simple can be applied to any spectral line sourced by galaxies. The Simpl...

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Main Authors: Maja Lujan Niemeyer, José Luis Bernal, Eiichiro Komatsu
Format: Article
Language:English
Published: IOP Publishing 2023-01-01
Series:The Astrophysical Journal
Subjects:
Online Access:https://doi.org/10.3847/1538-4357/acfef4
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author Maja Lujan Niemeyer
José Luis Bernal
Eiichiro Komatsu
author_facet Maja Lujan Niemeyer
José Luis Bernal
Eiichiro Komatsu
author_sort Maja Lujan Niemeyer
collection DOAJ
description We present the Simple Intensity Map Producer for Line Emission ( Simple ), a public code for quickly simulating mock line-intensity maps, and an analytical framework for modeling intensity maps including observational effects. Simple can be applied to any spectral line sourced by galaxies. The Simple code is based on lognormal mock catalogs of galaxies including positions and velocities and assigns luminosities following the luminosity function. After applying a selection function to distinguish between detected and undetected galaxies, the code generates an intensity map, which can be modified with anisotropic smoothing, noise, a mask, and sky subtraction, and it calculates the power spectrum multipoles. We show that the intensity auto-power spectrum and the galaxy-intensity cross-power spectrum agree well with the analytical estimates in real space. We derive and show that the sky subtraction suppresses the intensity autopower spectrum and the cross-power spectrum on scales larger than the size of an individual observation. As an example application, we make forecasts for the sensitivity of an intensity mapping experiment similar to the Hobby–Eberly Telescope Dark Energy Experiment (HETDEX) to the cross-power spectrum of Ly α -emitting galaxies and the Ly α intensity. We predict that HETDEX will measure the galaxy-intensity cross-power spectrum with a high signal-to-noise ratio on scales of 0.04 h Mpc ^−1 < k < 1 h Mpc ^−1 .
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spelling doaj-art-c727edb60e004c3cb4bb4a5befb034fb2025-08-20T03:10:13ZengIOP PublishingThe Astrophysical Journal1538-43572023-01-019581410.3847/1538-4357/acfef4SIMPLE: Simple Intensity Map Producer for Line EmissionMaja Lujan Niemeyer0https://orcid.org/0000-0002-6907-8370José Luis Bernal1https://orcid.org/0000-0002-0961-4653Eiichiro Komatsu2https://orcid.org/0000-0002-0136-2404Max-Planck-Institut für Astrophysik , Karl-Schwarzschild-Str. 1, D-85741 Garching, GermanyMax-Planck-Institut für Astrophysik , Karl-Schwarzschild-Str. 1, D-85741 Garching, Germany; Instituto de Física de Cantabria (IFCA), CSIC-Univ. de Cantabria , Avda. de los Castros s/n, E-39005 Santander, SpainMax-Planck-Institut für Astrophysik , Karl-Schwarzschild-Str. 1, D-85741 Garching, Germany; Kavli Institute for the Physics and Mathematics of the Universe (Kavli IPMU, WPI), University of Tokyo , Chiba 277-8582, JapanWe present the Simple Intensity Map Producer for Line Emission ( Simple ), a public code for quickly simulating mock line-intensity maps, and an analytical framework for modeling intensity maps including observational effects. Simple can be applied to any spectral line sourced by galaxies. The Simple code is based on lognormal mock catalogs of galaxies including positions and velocities and assigns luminosities following the luminosity function. After applying a selection function to distinguish between detected and undetected galaxies, the code generates an intensity map, which can be modified with anisotropic smoothing, noise, a mask, and sky subtraction, and it calculates the power spectrum multipoles. We show that the intensity auto-power spectrum and the galaxy-intensity cross-power spectrum agree well with the analytical estimates in real space. We derive and show that the sky subtraction suppresses the intensity autopower spectrum and the cross-power spectrum on scales larger than the size of an individual observation. As an example application, we make forecasts for the sensitivity of an intensity mapping experiment similar to the Hobby–Eberly Telescope Dark Energy Experiment (HETDEX) to the cross-power spectrum of Ly α -emitting galaxies and the Ly α intensity. We predict that HETDEX will measure the galaxy-intensity cross-power spectrum with a high signal-to-noise ratio on scales of 0.04 h Mpc ^−1 < k < 1 h Mpc ^−1 .https://doi.org/10.3847/1538-4357/acfef4Observational cosmologyLarge-scale structure of the universeLyα galaxies
spellingShingle Maja Lujan Niemeyer
José Luis Bernal
Eiichiro Komatsu
SIMPLE: Simple Intensity Map Producer for Line Emission
The Astrophysical Journal
Observational cosmology
Large-scale structure of the universe
Lyα galaxies
title SIMPLE: Simple Intensity Map Producer for Line Emission
title_full SIMPLE: Simple Intensity Map Producer for Line Emission
title_fullStr SIMPLE: Simple Intensity Map Producer for Line Emission
title_full_unstemmed SIMPLE: Simple Intensity Map Producer for Line Emission
title_short SIMPLE: Simple Intensity Map Producer for Line Emission
title_sort simple simple intensity map producer for line emission
topic Observational cosmology
Large-scale structure of the universe
Lyα galaxies
url https://doi.org/10.3847/1538-4357/acfef4
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AT joseluisbernal simplesimpleintensitymapproducerforlineemission
AT eiichirokomatsu simplesimpleintensitymapproducerforlineemission