Tentative Detection of Quasar Feedback from WMAP and SDSS
  Cross-Correlation
  We perform a cross-correlation analysis of microwave data from Wilkinson
Microwave Anisotropy Probe and photometric quasars from the Sloan Digital Sky
Survey, testing for Sunyaev-Zeldovich (SZ) effect from quasars.
  A statistically significant (2.5 $\sigma$) temperature decrement exists in
the 41 GHz microwave band. A two-component fit to the cross-correlation
spectrum incorporating both dust emission and SZ yields a best-fit $y$
parameter of $(7.0 \pm 3.4)\times 10^{-7}$. A similar cross-correlation
analysis with the Luminous Red Galaxy sample from Sloan gives a best-fit $y$
parameter of $(5.3 \pm 2.5)\times 10^{-7}$. We discuss the possible physical
origin of these signals, which is likely a combination of SZ effects from
quasars and from galaxy clusters. Both the Planck Surveyor satellite and
current ground-based arcminute-resolution microwave experiments will detect
this signal with a higher statistical significance.
