Measuring Bulk Flow of Galaxy Clusters using Kinematic
  Sunyaev-Zel'dovich effect: Prediction for Planck
  We predict the performance of the Planck satellite in determining the bulk
flow through kinetic Sunyaev-Zeldovich (kSZ) measurements. As velocity tracers,
we use ROSAT All-Sky Survey (RASS) clusters as well as expected cluster
catalogs from the upcoming missions Planck and eRosita (All-Sky Survey: EASS).
We implement a semi-analytical approach to simulate realistic Planck maps as
well as Planck and eRosita cluster catalogs. We adopt an unbiased kinetic SZ
filter (UF) and matched filter (MF) to maximize the cluster kSZ signal to noise
ratio. We find that the use of Planck CMB maps in conjunction with the
currently existing ROSAT cluster sample improves current upper limits on the
bulk flow determination by a factor \sim 5 (\sim 10) when using the MF (UF).
The accuracy of bulk flow measurement increases with the depth and abundance of
the cluster sample: for an input bulk velocity of 500 km/s, the UF recovered
velocity errors decrease from 94 km/s for RASS, to 73 km/s for Planck and to 24
km/s for EASS; while the systematic bias decreases from 44% for RASS, 5% for
Planck, to 0% for EASS. The 95% upper limit for the recovered bulk flow
direction \Delta {\alpha} ranges between 4 \circ and 60 \circ depending on
cluster sample and adopted filter. The kSZ dipole determination is mainly
limited by the effects of thermal SZ (tSZ) emission in all cases but the one of
EASS clusters analyzed with the unbiased filter. This fact makes the UF
preferable to the MF when analyzing Planck maps.
