Finding the Missing Baryons Using CMB as a Backlight

Abstract

We present a new method for detecting the missing baryons by generating a template for the kinematic Sunyaev-Zel'dovich effect. The template is computed from the product of a reconstructed velocity field with a galaxy field; we find that the combination of a galaxy redshift survey such as SDSS and a CMB survey such as ACT and PLANCK can detect the kSZ, and thus the ionized gas, at significant signal-to-noise. Unlike other techniques that look for hot gas or metals, this approach directly detects the electrons in the IGM through their signature on the CMB. The estimated signal-to-noise for detecting the galaxy-momentum kSZ cross-correlation is 4, 9, and 12 for ACT (with survey area of 2000 ${\mathrm{deg}}^2$) with SDSS-DR4, SDSS3 and ADEPT respectively. The estimated signal-to-noise for PLANCK with SDSS-DR4, SDSS3 and ADEPT is 11, 23, and 32. Our method provides a new mean for determining properties of the ionized gas in the Universe. We provide galaxy momentum templates constructed from Sloan Digital Sky Survey online at our website at http://www.astro.princeton.edu/~shirley/SZ/SZ.html. The predicted correlation coefficients are provided along with the momentum maps. One can download the momentum templates and cross-correlate directly with CMB maps from ACT and PLANCK to detect the missing baryons.

11 pages, 5 figures, to be submitted to PRD; momentum templates and analytical code at: http://www.astro.princeton.edu/~shirley/SZ/SZ.html

Cited by in corpus (19)

• CMB-S4 Science Case, Reference Design, and Project Plan
• ACTPol: A polarization-sensitive receiver for the Atacama Cosmology Telescope
• The Tau of Galaxy Clusters
• Future constraints on halo thermodynamics from combined Sunyaev-Zel'dovich measurements
• First measurement of the bulk flow of nearby galaxies using the cosmic microwave background
• Matched filter optimization of kSZ measurements with a reconstructed cosmological flow field
• Projected-Field Kinetic Sunyaev-Zel'dovich Cross-Correlations: Halo Model and Forecasts
• Analyzing the cosmic variance limit of remote dipole measurements of the cosmic microwave background using the large-scale kinetic Sunyaev Zel'dovich effect
• A direct measure of free electron gas via the Kinematic Sunyaev-Zel'dovich effect in Fourier-space analysis
• Kinetic Sunyaev-Zel'dovich tomography with line-intensity mapping
• Extracting the late-time kinetic Sunyaev-Zel'dovich effect
• Simulated reconstruction of the remote dipole field using the kinetic Sunyaev Zel'dovich effect
• Reconstruction with velocities
• Nonlinear Reconstruction of the Velocity Field
• The kinetic Sunyaev-Zel'dovich tomography II: probing the circumgalactic medium
• Tracing the 10${}^7$K Warm-Hot Intergalactic Medium with UV absorption lines
• A Space Mission to Map the Entire Observable Universe using the CMB as a Backlight
• Tentative Detection of Quasar Feedback from WMAP and SDSS Cross-Correlation
• Testing eternal inflation with the kinetic Sunyaev Zel'dovich effect