An Improved Measurement of the Secondary Cosmic Microwave Background
  Anisotropies from the SPT-SZ + SPTpol Surveys
  We report new measurements of millimeter-wave power spectra in the angular
multipole range $2000 \le \ell \le 11,000$ (angular scales $5^\prime \gtrsim
\theta \gtrsim 1^\prime$). By adding 95 and 150\,GHz data from the low-noise
500 deg$^2$ SPTpol survey to the SPT-SZ three-frequency 2540 deg$^2$ survey, we
substantially reduce the uncertainties in these bands. These power spectra
include contributions from the primary cosmic microwave background, cosmic
infrared background, radio galaxies, and thermal and kinematic
Sunyaev-Zel'dovich (SZ) effects. The data favor a thermal SZ (tSZ) power at
143\,GHz of $D^{\rm tSZ}_{3000} = 3.42 \pm 0.54~ \mu {\rm K}^2$ and a kinematic
SZ (kSZ) power of $D^{\rm kSZ}_{3000} = 3.0 \pm 1.0~ \mu {\rm K}^2$. This is
the first measurement of kSZ power at $\ge 3\,\sigma$. We study the
implications of the measured kSZ power for the epoch of reionization, finding
the duration of reionization to be $\Delta z_{re} = 1.0^{+1.6}_{-0.7}$ ($\Delta
z_{re}< 4.1$ at 95% confidence), when combined with our previously published
tSZ bispectrum measurement.
