Recovering the SZ Redshift Information by SZgalaxy Cross Correlation

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Recovering the SZ Redshift Information by
SZ-galaxy Cross Correlation

• Jiawei Shao, Pengjie Zhang, Weipeng Lin, Yipeng
  Jing
• ???,???,???,???
• Shanghai Astronomical Observatory, Shanghai, China

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The Sunyaev Zeldovich effect

• The thermal Sunyaev Zeldovich (SZ) effect is
  the dominant secondary CMB anisotropy, arising
  from the inverse Compton scattering of CMB
  photons by free electrons. The SZ temperature
  decrement in the Rayleigh-Jeans regime is
• It directly measures the thermal energy of free
  electrons (the majority of electrons in the
  universe)
• And contains valuable information on
  gravitational heating, feedback, and radiative
  cooling and is thus a powerful probe of the
  thermal history of the universe
• However, the redshift information of the SZ
  effect is smeared by the projection along the
  line of sight

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Recovering the SZ redshift information through
SZ-galaxy cross correlation

• Both the SZ effect and galaxy distribution trace
  the same underlying matter distribution, thus
  there exists strong correlation between the two
• By the redshift information of galaxies and the
  cross correlation method, the SZ redshift
  information can be recovered
• Some details (1) Galaxy auto correlation and
  SZ-galaxy cross correlation can be directly
  measured, as a function of redshift. (2) Given
  the knowledge of the relation between galaxy auto
  correlation, SZ-galaxy cross correlation and the
  SZ auto correlation, one can recover the SZ auto
  correlation at each redshift and thus reconstruct
  the clustering of electron thermal energy at
  each redshift

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Some preliminary results
WMAP cosmology GADGET2, adiabatic run 5123 DM
particles5123 SPH particles 100 h-1 Mpc box size