Alessio Notari, Miguel Quartin
It was recently shown that our peculiar velocity $\beta$ with respect to the
CMB induces mixing among multipoles and off-diagonal correlations at all scales
which can be used as a measurement of $\beta$, which is independent of the
standard measure using the CMB temperature dipole. The proposed techniques rely
however in an perturbative expansion which breaks down for $\ell \gtrsim
1/\beta = 800$. Here we propose a technique which consists of deboosting the
CMB temperature in the time-ordered data and show that it extends the validity
of the perturbation analysis multipoles up to $\ell ~ 10000$. We also obtain
accurate fitting functions for the mixing between multipoles valid in a full
non-linear treatment. Finally we forecast the achievable precision with which
these correlations can be measured in a number of current and future CMB
missions. We show that ACTPol could measure the velocity with a precision of
around 70 km/s, Planck around 60 km/s, while proposed future experiments could
shrink this error bar by over a factor of 2.
View original:
http://arxiv.org/abs/1112.1400
No comments:
Post a Comment