A NEW UBV AND PROPER MOTION SURVEY IN THE ANTICENTRE DIRECTION AT INTERMEDIATE GALACTIC LATITUDE - KINEMATICS OF THE GALAXY STELLAR POPULATIONS

We present the results from a new complete absolute proper motion surv ey in the direction of intermediate galactic latitude (1 = 167.5-degre es, b = 47.4-degrees) with respect to background galaxies and quasars, using a set of Tautenburg and OCA (Observatoire de la Cote d'Azur) Sc hmidt plates, obtained at different epochs separated by approximately 25 years. Photometric U, B and V survey has been done for 4167 objects covering 18.8 square degree field and proper motions have been calcul ated for 1888 objects for a 8.6 deg2 area. The resulting catalogues ar e complete down to V = 17, B = 19 and U = 16.5. An average proper moti on accuracy of 0.25'' per century was achieved for stars brighter than V = 16, with the uncertainties increasing to approximately 0.4'' per century at V > 16. The photometric accuracy ranges between 0.07 to 0.1 0 in the three bands. We utilize our photometric and absolute proper m otions data to investigate the structure and kinematics of the Galaxy. We have determined ultraviolet excesses and distances for a subsample of 2685 stars in the color range 0.3 less-than-or-equal-to (B-V) less -than-or-equal-to 0.9 and with V less-than-or-equal-to 17. Thus we hav e been able to probe the kinematical distribution of F and G- type sta rs to distances up to 3.5 kpc from the plane. We obtain a value -0.21 +/- 0.1 kpc-1 for the galactic radial gradient of velocity dispersion (partial derivative lnsigma(U+W)2/partial derivative r). By comparing the ratio of stars in this direction to the number of stars towards ga lactic centre at intermediate latitude (l = 3-degrees, b = 47-degrees) , give a strong evidence that the scale length of old disk is rather s hort (2-2.5 kpc). Because of the kinematical biases inherent in our da ta sample, we can not present definite kinematical parameters for the intermediate population, but reasonable estimates would be an asymmetr ic drift of 57 +/- 4 km s-1 and velocity dispersion (sigma(V)) of 60 /- 3 km s-1 at a mean distance (above the plane) of z = 2 kpc.