Impact of Dust on Spectral Distortion Measurements of the Cosmic Microwave Background

Abstract

Spectral distortions of the cosmic microwave background (CMB) are sensitive to energy injection by exotic physics in the early universe. The proposed Primordial Inflation Explorer (PIXIE) mission has the raw sensitivity to provide meaningful limits on new physics, but only if foreground emission can be adequately modeled. We quantify the impact of interstellar dust on Compton $y$ and $\mu$ measurements by considering a range of grain size distributions and compositions constrained by theoretical and observational priors (Zelko & Finkbeiner 2020). We find that PIXIE can marginalize over a modest number of dust parameters and still recover $y$ and $\mu$ estimates, though with increased uncertainty. As more foreground components are included (synchrotron, free-free), the estimates of $y$ degrade, and measurement of $\mu$ in the range sometimes considered for the standard $\Lambda$CDM of $2\times 10^{-8}$ becomes infeasible without ancillary low-frequency foreground information. An additional concern is dust absorption of the CMB monopole, a subtle effect that must be included. We quantify one form of model discrepancy error, finding that the error introduced by fitting our interstellar medium dust model with a modified blackbody is too large for CMB spectral distortions to be detectable. The greatest challenge may be the cosmic infrared background (CIB). We find that $\mu$ and $y$ are extremely sensitive to modeling choices for the CIB, and quantify biases expected for a range of assumptions.

arXiv commentPublished in the Astrophysical Journal. 25 pages, 12 figures, 10 tables. Updated to reflect the journal version. Corrected a typo in the Appendix Eq A6 and A9; updated the tables 5,6,7 (first column). There were no changes to the qualitative nature of the results

References in corpus (32)

• The NumPy array: a structure for efficient numerical computation
• Dust Grain Size Distributions and Extinction in the Milky Way, LMC, and SMC
• The Cosmic Microwave Background Spectrum from the Full COBE/FIRAS Data Set
• Infrared Emission from Interstellar Dust. II. The Diffuse Interstellar Medium
• The Temperature of the Cosmic Microwave Background
• First Year Wilkinson Microwave Anisotropy Probe (WMAP) Observations: Foreground Emission
• Planck 2013 results. XI. All-sky model of thermal dust emission
• The Cosmic Infrared Background: Measurements and Implications
• The Primordial Inflation Explorer (PIXIE): A Nulling Polarimeter for Cosmic Microwave Background Observations
• Extrapolation of Galactic Dust Emission at 100 Microns to CMBR Frequencies Using FIRAS
• The evolution of CMB spectral distortions in the early Universe
• Dynamic temperature selection for parallel-tempering in Markov chain Monte Carlo simulations
• Planck 2013 results. XXX. Cosmic infrared background measurements and implications for star formation
• Planck 2015 results. X. Diffuse component separation: Foreground maps
• The Optical-Infrared Extinction Curve and its Variation in the Milky Way
• FAR-INFRARED SPECTRAL OBSERVATIONS OF THE GALAXY BY COBE
• CMB at 2x2 order: the dissipation of primordial acoustic waves and the observable part of the associated energy release
• Teasing bits of information out of the CMB energy spectrum
• Rethinking CMB foregrounds: systematic extension of foreground parameterizations
• Beyond y and μ: the shape of the CMB spectral distortions in the intermediate epoch, 1.5x10^4 < z < 2x10^5
• Taking the Universe's Temperature with Spectral Distortions of the Cosmic Microwave Background
• Prospects for Measuring Cosmic Microwave Background Spectral Distortions in the Presence of Foregrounds
• Planck intermediate results. XLVIII. Disentangling Galactic dust emission and cosmic infrared background anisotropies
• Large-scale Maps of the Cosmic Infrared Background from Planck
• Mapping the relativistic electron gas temperature across the sky
• Combining ILC and moment expansion techniques for extracting average-sky signals and CMB anisotropies
• Planck intermediate results. XLIII. The spectral energy distribution of dust in clusters of galaxies
• Calibration Method and Uncertainty for the Primordial Inflation Explorer (PIXIE)
• Implications of Grain Size Distribution and Composition for the Correlation Between Dust Extinction and Emissivity
• The Distortion of the Cosmic Microwave Background Spectrum Due to Intergalactic Dust
• CMB Shadows: The Effect of Interstellar Extinction on Cosmic Microwave Background Polarization and Temperature Anisotropy
• Time-ordered data simulation and map-making for the PIXIE Fourier transform spectrometer

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