Planck intermediate results. XXVI. Optical identification and redshifts
  of Planck clusters with the RTT150 telescope
  We present the results of approximately three years of observations of Planck
Sunyaev-Zeldovich (SZ) sources with the Russian-Turkish 1.5-m telescope
(RTT150), as a part of the optical follow-up programme undertaken by the Planck
collaboration. During this time period approximately 20% of all dark and grey
clear time available at the telescope was devoted to observations of Planck
objects. Some observations of distant clusters were also done at the 6-m
Bolshoy Telescope Azimutal'ny (BTA) of the Special Astrophysical Observatory of
the Russian Academy of Sciences. In total, deep, direct images of more than one
hundred fields were obtained in multiple filters. We identified 47 previously
unknown galaxy clusters, 41 of which are included in the Planck catalogue of SZ
sources. The redshifts of 65 Planck clusters were measured spectroscopically
and 14 more were measured photometrically. We discuss the details of cluster
optical identifications and redshift measurements. We also present new
spectroscopic redhifts for 39 Planck clusters that were not included in the
Planck SZ source catalogue and are published here for the first time.
