Restoration of the vector velocity field of NGC 157 are based on the observations at 6-m telescope of Special Astrophysical Observatory RAS in 1995. Observations were carried out in Halpha line with the scanning Fabry-Perot interferometer and the focal reducer attached to the prime focus of the telescope. Two-dimensional photon-counting system 512x512 operating in the TRIM-mode was used as a detector. The data reductions (phase recalibration, flatfielding, velocity calculations etc.) were made by using software ADHOC developed in the Marseille Observatory. As a result, we have obtained a data cube of 256x256x32 with a spatial bin 0.92''/px and spectral bin 19 km/s. The angular resolution was about 2.5'' and the spectral one 40-50 km/s. Standart error of one velocity measurements is 14-15 km/s. In general, more than 11 000 measurements of line-of-sight velocities were obtained all over the disc of the galaxy. The best fit parameters of the galactic disk of NGC 157 are: systemic velocity Vs= 1667 km/s, position angle of major dynamical axis PA=223.o5, inclination angle i= -51.o5 (the minus is a result of an assumption that the spiral arms in the galaxy are trailing).
This figure is produced with the help of software VORTEX developed in the Institute of Astronomy of the Russian Academy of Sciences.
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