Optical Identifications of High-Redshift Galaxy Clusters from the Planck Sunyaev-Zeldovich Survey
Aghanim, N.; Bikmaev, I. F.; Khamitov, I. M.; Sunyaev, R. A.; Afanasiev, V. L.; Eselevich, M. V.; Khorunzhev, G. A.; Burenin, R. A.; Zaznobin, I. A.; Dodonov, S. N.; Rubiño-Martín, J. -A.
Russia, Turkey, Spain, France, Germany
Abstract
We present the results of optical identifications and spectroscopic redshift measurements for galaxy clusters from the second Planck catalogue of Sunyaev-Zeldovich sources (PSZ2) located at high redshifts, z ≈ 0.7-0.9. We used the data of optical observations with the Russian-Turkish 1.5-mtelescope (RTT-150), the Sayan Observatory 1.6-m telescope, the Calar Alto 3.5-m telescope, and the 6-m SAO RAS telescope (BTA). The spectroscopic redshift measurements were obtained for seven galaxy clusters, including one cluster, PSZ2 G126.57+51.61, from the cosmological sample of the PSZ2 catalogue. In the central regions of two clusters, PSZ2 G069.39+68.05 and PSZ2 G087.39-34.58, we detected arcs of strong gravitational lensing of background galaxies, one of which is at redshift z = 4.262. The data presented below roughly double the number of known galaxy clusters in the second Planck catalogue of Sunyaev-Zeldovich sources at high redshifts, z ≈ 0.8.