I review our series of works on the galactic evoluton putting emphasis on some fundaments of he models instead that on their detailed structure. I show, with some example how the mathematical formulation is produced from the physical input, how it can be modified as physics is enriched, and which kind of results can be provided.
Broad-band UBV light and color observations of KY And obtained in September 1982 at the Hvar Observatory have been analyzed. It was found that no single frequency satisfied the data well enough, hence, a multifrequency fit has been determined.
We present an hitherto unknown cometary reflection nebula {a = 20^h18^m3, δ+37°00') associated with a dense dust cloud. A bright, compact Herbig-Haro oject is embedded in its brightest part. The highly reddened illuminating star of about 3-5 M„, located near the apex of the nebula, emits a collimated bipolar flow at high velocity, whose blueshifted stream feeds the HH object. The redshifted stream can be traced toward the interior of the dark cloud, where the density exceeds 10^5 cm^-3.
A method of reduction of dimensionality in discriminant analysis has been specially designed for this study of separation between two populations and it is only based on the heterocedasticity
of both groups. For this reason, it is of interest in the case of zero mean difference vector. Two examples of application, concerning the membership problem in open clusters from uvby and
Hβ photometry and the separation of globular clusters into Oosterhoff's groups are shown.
Galactlc bars are thlcker than Inner parts of gas dlsks. Therefore
gas flow Into theback side of bars, relatlve to the dlrectlon of dlsc
rotation, Thls Idea, based on the equlllbrium condltlon for galactlc rotating subsystems Is used to Interprete forbldden line emlsslon In bar regione vhere gas Inflow supersonic.
The suggested interpretation of the phenomenon of dlfferent velocity fields in the linea of dlfferent excltetion first discovered in the Seyfert galaxy Mkn 744 • NGC 3786 is now checked in the case of another Seyfert NGC 1068. .The appllcabillty Is controled from the Inferences concemlng the sense of rotation of spiral arms In the galaxies. In both cases these agree wlth the earlier results obtalned from Independent methods t the arms In NGC 1068 are trailling, while in NGC 3786 they are leadlng. One of manifestations of the shock back along the front slde of bars Is the occurence of stralght dust lanes along the front aide. Applications of the method
to other observational problems are discussed.
In recent papers Henrard and Lemaître have studied what they call "The Second Fundamental Model for Resonance" and higher order generalizations of it. The action integral ("area index") was computed analytically, but the phase space and the action integral as a function of the parameter δ were only plotted on scale by a computer. By using properties of quartic equations, however, the mathematically special values of δ were found. For third order resonances, one of these turned out to correspond to a minimum
in the value of the "area index" A2, but since it is very shallow and very close to the starting point of the function, this feature was invisible in Lemaître's plots, This has some theoretical implications for the process of capture into a third order resonance, although numerically the effect will be small due to the shallowness of the minimum. A similar exercise on first and second order resonances revealed no new features.