... 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" . ...

... FTP access the basic models is here . ... Below, we put short descriptions of the used SED models for the photometric redshifts providing by the current server . ... The uniqueness of this model consists in expanding to the near IR (NIR) of Rocca-Volmerange and Guiderdoni's (1988) atlas of synthetic spectra with a revised stellar library, which includes parameters of cool stars. ... Homepage of the GISSEL model). ... Another model used earlier is the model of synthetic spectra of Poggianti (1997). ...

There are still many open questions on galaxy formation and evolution, such as e.g. the predominance of hierarchical or monolithic processes in the galaxy formation or the temporal evolution of disk metallicity gradients. ... Chemical abundances of stellar populations of different ages are essential to constrain the past history of nearby galaxies, both in terms of their past metal contents and of SFHs. ...

... Chandra Observation of DEEP2 Galaxy Groups and Clusters . ... Monday: 'Normal' Galaxies, Tuesday: Cluster Formation and Evolution . ... Statistics of galaxy groups in ultradeep XMM surveys. ... What can multiwavelength observations tell about cluster/group formation as well as galaxy evolution? ... I will present results from a Chandra study of eight low-redshift clusters that has systematically measured the AGN fraction in clusters and describe their spatial, kinematic, and host galaxy...

Chiaki Kobayashi, Ralph Sutherland How galaxies did form and evolution? - to answer this unsolved problem, we are simulating the formation and evolutionary history of galaxies in the Universe, including star formation, supernovae feedback, and chemical enrichment. Comparing the spacial distribution of elements within galaxies with observations, we will examine fundamental physical processes that drive galaxy formation. ... COALA : Universe Galaxy AGN Star Planet ...

Scale-heights of the Galactic disk subsytems with different ages and metallicities . V.Marsakov & Yu. ... It is based on the fact, that all stars cross the disk plane several times during their Galactic orbital period. ... We have used our representative sample of nearby disk F2-G2 stars Marsakov & Shevelev (1995) in which fundamental stellar parameters was determined on the basis of published date on uvby-photometry, proper motion and radial velocities. ... Marsakov V.A., Shevelev Yu.G. Bull. ...

... It is reasonable to expect that UV part of the irradiating spectrum is most influenced by the grain evolution (growth and sedimentation ) which marks the very initial stage of planet formation. 2 log J [erg s­1 cm­2] 1 0 -1 -2 -3 1000 BB 40 0 0 (A5 ) BB 20 0 00 (A5) Drai ne (A5 ) BP Ta u (A5) BB 40 0 0 (GS) BB 20 0 00 (GS) Drai ne (GS) BP Ta u (GS) Disk Model Density distribution is based on a 1+1D disk ... Green lines are used for a model with dust growth and sedimentation. ...

... Galaxy Evolution home . ... Regulating the ISM and star formation . Cosmological evolution of star-forming galaxies . The origin and evolution of radio sources . Radio sources and their environments . ... Observations of the local Universe clearly demonstrate that very active star formation phases (starbursts) are often associated with interacting and merging galaxies and that in these systems much of the short wavelength emission is absorbed by dust and re-emitted in the IR. ...

... Stellar Evolution is driven entirely by the never ending battle between Pressure and Gravity . As imbalances are reached, the star is driven to find a new Energy source. ... Pressure and gravitational forces are equal, the star is stable and its core is sufficiently hot to fuse Hydrogen into Helium More about main sequence stars . ... The luminosity generated by the core fusion of Helium into Carbon is far greater than the shell luminosity associated with the fusion of Hydrogen into Helium. ...

... Mass loss Recipes | ... Mass Loss is the most important "driver" of stellar evolution in massive stars. ... The final goal is to predict mass loss over the entire evolution of a massive star at all cosmological epochs. ... Very Massive Stars are objects up to 300 times the mass of the Sun. ... Mass-loss rates increase dramatically when objects cross a critical Eddington Gamma factor (Vink et al. ... I have recently edited a book on "Very Massive Stars" including a mass-loss "chapter" . ...