Multi-object spectroscopy in the observational complex of the RTT150

Abstract

The multi-object spectroscopy technique was implemented on the Russian-Turkish 1.5m optical telescope (aka. RTT150) by modifying the slit wheel of its main instrument TFOSC (TÜBİTAK Faint Object Spectrograph and Camera). Remotelycontrolled rotating holders of the multi object masks were installed in the two nests of the slit wheel. The accuracy of the mask unit’s rotation is the order of 1 arcmin, in which the image plane for 2 sources located at a separation of 5 arcmin corresponds to a positional accuracy of 0.1 arcsec. To investigate the quality of the MOS technique in RTT150, the well-known merging galaxy cluster Abell 1914 was observed spectroscopically. The dispersion of the differences between known and RTT150 redshift estimations is 0.0006, which is good enough for cosmological studies.