• Corpus ID: 116312924

Finding the Missing Baryons Using CMB as a Backlight

@article{Ho2009FindingTM,
  title={Finding the Missing Baryons Using CMB as a Backlight},
  author={Shirley Ho and Simon Dedeo and David N. Spergel},
  journal={arXiv: Cosmology and Nongalactic Astrophysics},
  year={2009}
}

• S. Ho, S. Dedeo, D. Spergel
• Published 16 March 2009
• Physics
• arXiv: Cosmology and Nongalactic Astrophysics

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 this http URL 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.