... It is reasonable to expect a priori that the evolution of events is strongly time dependent, so the star formation history in a galaxy is another important parameter. Therefore, by calculating the evolution of events after a -function like star formation burst,   one gets a Green function for any arbitrary star formation history. ... The source evolution in a galaxy with given star formation rate is thus calculated as . ...

One possible way for spiral galaxies to internally evolve would be for gas to flow to the center and form stars in a central disk (pseudo-bulge). ... In this paper we present radial profiles of stellar and 8 ЮМm emission from polycyclic aromatic hydrocarbons (PAHs) for 11 spiral galaxies to investigate whether the interstellar medium in these galaxies contains a central concentration above that expected from the exponential disk. ...

Next: Spectral observations and data Up: The Hamburg/SAO Survey for Previous: The Hamburg/SAO Survey for . ... The basic outline of the HSS and first results are described in Paper I (Ugryumov et al. [ 1999 ]), while additional results from follow-up spectroscopy are given in papers II, III and IV (Pustilnik et al. ... Next: Spectral observations and data Up: The Hamburg/SAO Survey for Previous: The Hamburg/SAO Survey for Laboratory "Structure" . ...