We present 2.2 micron maps of selected areas of the Galactic Plane, taken with the 1.5 m. Sánchez-Magro telescope on the island of Tenerife. A model of the galactic stellar distribution has been developed and the derived stellar surface densities are compared with the observations. The results are in good agreement with the experimental data and suggest remarkable differences between
the luminosity functions for the disk and the spheroid components. The extinction toward the galactic centre shows an abrupt increase when compared with other galactic directions. We note also that a
better fit is obtained when the 5 Kpc ring is included in the model, but cannot infer from our data the existence of a thick disk.
The galactic plane has been sampled at 5´ spacing between l = 38° and J = 1-0 line of 13CO with the 2.5 m telescope of the Bordeaux Observatory. An automatic analysis of the data gives 181 clouds with masses ranging from a few solar msses to a few 10^5 M. Two spirals at liast can be fitted to our data.
In this paper, a theory of the causes of condensations i the central parts of open star clusters is developed, which are in the state of approximate statistical equilibrium. A method is proposed of establishing the mean diameter of star clusters. Owing to galactic rtation, clusters of central densities smaller than 4.5 solar masses/parsec^3 show some elongation in the direction of the galactic plane. Clusters of central densities larger than 0.5 solar masses/parsec^3 may, as a whole, be regarded as stationary and their state as statistically in equilibrium. Assuming Maxwell´s velocity distribution, stars from the central parts of the star clusters will, on account of the shorter relaxation time, tend to escape quicker than these from the border. The star clusters will therefore contract quicker around the centre than at the border. After the state of the cluster has become stationary its central part has a larger kinetic energy than the border parts, in spite of the fact that the star energies of various cluster regions adjust themselves. The paper derives a method of determining initial residual star velocities in the cluster. Today´s value of the residual velocity, together with the initial velocity, allow us to estimate the age of the star cluster. The theoretical results were applied to moving cluster Hyades. The age was estimated as 1.1 x 10^9 years. The theoretical flatness of the cluster 0.69 agrees well with the observed value of 0.07, given by van Bueren [19].
Vertex deviation in the galactic plane is not compatible with the
Oort-Lindbalad theory about galactic rotation (stationary system with cylindrical symmetry). However, like we show in this work, it can be obtained in a stellar system model that verifies the Chandrasekhar postulates in a non-stationary state, axial symmetry, non-cylindrical, and with an equatorial plane of symmetry.