A model of spectral line broadening in signal forecasts for line-intensity mapping experiments

Abstract

Line-intensity mapping observations will find fluctuations of integrated line emission are attenuated by varying degrees at small scales due to the width of the line emission profiles. This attenuation may significantly impact estimates of astrophysical or cosmological quantities derived from measurements. We consider a theoretical treatment of the effect of line broadening on both the clustering and shot-noise components of the power spectrum of a generic line-intensity power spectrum using a halo model. We then consider possible simplifications to allow easier application in analysis, particularly in the context of inferences that require numerous, repeated, fast computations of model line-intensity signals across a large parameter space. For the CO Mapping Array Project (COMAP) and the CO(1-0) line-intensity field at $z\sim 3$ serving as our primary case study, we expect a $\sim 10\%$ attenuation of the spherically averaged power spectrum on average at relevant scales of $k\approx 0.2$-$0.3$ Mpc${}^{-1}$, compared to $\sim 25\%$ for the interferometric Millimetre-wave Intensity Mapping Experiment (mmIME) targeting shot noise from CO lines at $z\sim 1$-$5$ at scales of $k\gtrsim 1$ Mpc${}^{-1}$. We also consider the nature and amplitude of errors introduced by simplified treatments of line broadening, and find that while an approximation using a single effective velocity scale is sufficient for spherically-averaged power spectra, a more careful treatment is necessary when considering other statistics such as higher multipoles of the anisotropic power spectrum or the voxel intensity distribution.

arXiv comment24 pages + appendix and bibliography (33 pages total), 16 figures, 2 tables; accepted for publication in ApJ

References in corpus (55)

• Astropy: A Community Python Package for Astronomy
• emcee: The MCMC Hammer
• Planck 2015 results. XIII. Cosmological parameters
• Nine-Year Wilkinson Microwave Anisotropy Probe (WMAP) Observations: Cosmological Parameter Results
• Statistical Properties of X-ray Clusters: Analytic and Numerical Comparisons
• The Average Star Formation Histories of Galaxies in Dark Matter Halos from z=0-8
• UniverseMachine: The Correlation between Galaxy Growth and Dark Matter Halo Assembly from z=0-10
• MultiDark simulations: the story of dark matter halo concentrations and density profiles
• 21-cm Tomography of the Intergalactic Medium at High Redshift
• The Interstellar Medium In Galaxies Seen A Billion Years After The Big Bang
• Baryon Acoustic Oscillation Intensity Mapping as a Test of Dark Energy
• CO excitation of normal star forming galaxies out to z=1.5 as regulated by the properties of their interstellar medium
• On the Lack of Evolution in Galaxy Star Formation Efficiency
• Ingredients for 21cm intensity mapping
• Intensity Mapping with Carbon Monoxide Emission Lines and the Redshifted 21 cm Line
• Tracing the reionization epoch with ALMA: [CII] emission in z~7 galaxies
• Line-Intensity Mapping: 2017 Status Report
• COLDz: Shape of the CO Luminosity Function at High Redshift and the Cold Gas History of the Universe
• The KMOS^3D Survey: data release and final survey paper
• Blind detections of CO J = 1--0 in 11 H-ATLAS galaxies at z = 2.1--3.5 with the GBT/Zpectrometer
• L'CO/LFIR Relations with CO Rotational Ladders of Galaxies Across the Herschel SPIRE Archive
• Connecting CO Intensity Mapping to Molecular Gas and Star Formation in the Epoch of Galaxy Assembly
• The SINS/zC-SINF Survey of z~2 Galaxy Kinematics: The Nature of Dispersion Dominated Galaxies
• PHIBSS2: survey design and z=0.5-0.8 results. Molecular gas reservoirs during the winding-down of star formation
• The KMOS Deep Survey (KDS) I: dynamical measurements of typical star-forming galaxies at z $\simeq$ 3.5
• The CO Luminosity Density at High-z (COLDz) Survey: A Sensitive, Large Area Blind Search for Low-J CO Emission from Cold Gas in the Early Universe with the Karl G. Jansky Very Large Array
• COPSS II: The Molecular Gas Content of Ten Million Cubic Megaparsecs at $z\sim 3$
• The mass-Peak Patch algorithm for fast generation of deep all-sky dark matter halo catalogues and its N-Body validation
• The ALMA Spectroscopic Survey in the HUDF: CO emission lines and 3 mm continuum sources
• Intensity mapping of [CII] from early galaxies
• On Removing Interloper Contamination from Intensity Mapping Power Spectrum Measurements
• Cross-correlations as a cosmological carbon monoxide detector
• The ALMA Spectroscopic Survey in the Hubble Ultra Deep Field: Evolution of the molecular gas in CO-selected galaxies
• A User's Guide to Extracting Cosmological Information from Line-Intensity Maps
• A wide field-of-view low-resolution spectrometer at APEX: instrument design and science forecast
• VLA-ALMA Spectroscopic Survey in the Hubble Ultra Deep Field (VLASPECS): Total Cold Gas Masses and CO Line Ratios for z=2-3 "Main Sequence" Galaxies
• An Intensity Mapping Detection of Aggregate CO Line Emission at 3 mm
• Constraining the evolution of CII intensity through the end stages of reionization
• Constraining the CO intensity mapping power spectrum at intermediate redshifts
• Predictions and sensitivity forecasts for reionization-era [C II] line intensity mapping
• Line intensity mapping with [CII] and CO(1-0) as probes of primordial non-Gaussianity
• A Self-consistent Framework for Multiline Modeling in Line Intensity Mapping Experiments
• Insights from probability distribution functions of intensity maps
• Joint power spectrum and voxel intensity distribution forecast on the CO luminosity function with COMAP
• Probing Cosmic Reionization and Molecular Gas Growth with TIME
• The Cosmic Expansion History from Line-Intensity Mapping
• Forecasting [C II] line-intensity mapping measurements between the end of reionization and the epoch of galaxy assembly
• Observing AGN feedback with CO intensity mapping
• Astrophysics & Cosmology from Line Intensity Mapping vs Galaxy Surveys
• The impact of the gas distribution on the determination of dynamical masses of galaxies using unresolved observations
• Redshift space distortions of the {\rm HI} 21-cm intensity mapping signal due to the internal motions within galaxies
• The Design of The CCAT-prime Epoch of Reionization Spectrometer Instrument
• A partial inventory of observational anisotropies in single-dish line-intensity mapping
• CO luminosity - line width correlation of sub-millimeter galaxies and a possible cosmological application
• An Empirical Mass Function Distribution

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• Line-Intensity Mapping: Theory Review
• COMAP Early Science: I. Overview
• COMAP Early Science: V. Constraints and Forecasts at $z\sim 3$
• Precision Tests of CO and [CII] Power Spectra Models against Simulated Intensity Maps
• COMAP Early Science: VII. Prospects for CO Intensity Mapping at Reionization
• An Intensity Mapping Constraint on the CO-Galaxy Cross Power Spectrum at Redshift ~ 3
• COMAP Early Science: IV. Power Spectrum Methodology and Results
• COMAP Early Science: III. CO Data Processing
• A multi-tracer empirically-driven approach to line-intensity mapping lightcones
• Exploration of 3D wavelet scattering transform coefficients for line-intensity mapping measurements
• The deconvolved distribution estimator: enhancing reionisation-era CO line-intensity mapping analyses with a cross-correlation analogue for one-point statistics
• Characteristic Functions for Cosmological Cross-Correlations
• COMAP Pathfinder -- Season 2 results I. Improved data selection and processing
• A Multi-messenger view of Cosmic Dawn: Conquering the Final Frontier
• Towards Accurate Modeling of Line-Intensity Mapping One-Point Statistics: Including Extended Profiles
• Towards Optimal Foreground Mitigation Strategies for Interferometric HI Intensity Mapping in the Low-Redshift Universe
• COMAP Pathfinder -- Season 2 results II. Updated constraints on the CO(1-0) power spectrum
• Leveraging cross-correlations and linear covariance-based filtering for line-intensity map reconstructions at linear scales
• COMAP Pathfinder -- Season 2 results III. Implications for cosmic molecular gas content at "Cosmic Half-past Eleven"
• Three-Dimensional Stacking as a Line Intensity Mapping Statistic
• Removal of interloper contamination to line-intensity maps using correlations with ancillary tracers of the large-scale structure