ﻻ يوجد ملخص باللغة العربية
Deep photometric observations in three colours of the cluster A 496 show that the luminosity function is bimodal with a deep gap at g about 19.0. That is there is a net separation between E/SO galaxies that are nicely fitted by a gaussian distribution curve and the dwarfs that better match a Shechter Function. This is the first cluster observed and reduced out of a sample of 19 clusters which we have in our program. However comparison with the data of Virgo and Coma might suggest a correlation between cluster morphology and amplitude of the two distribution: Normal and dwarf population. This would have strong implication for the understanding of cluster formation and evolution so that we are pursuing the estimate of the LF in various colours and to faint magnitudes both for low and high redshift clusters.
Context. Statistical properties of HII region populations in disk galaxies yield important clues to the physics of massive star formation. Aims. We present a set of HII region catalogues and luminosity functions for a sample of 56 spiral galaxies i
The protostellar luminosity function (PLF) is the present-day luminosity function of the protostars in a region of star formation. It is determined using the protostellar mass function (PMF) in combination with a stellar evolutionary model that provi
The Smithsonian Hectospec Lensing Survey (SHELS) is a window on the star formation history over the last 4 Gyr. SHELS is a spectroscopically complete survey for Rtot < 20.3 over 4 square degrees. We use the 10k spectra to select a sample of pure star
We examine a sample of low redshift (10 < d < 150 Mpc) galaxies including galaxies with r-band absolute magnitudes as faint as -12.5 (for h=1), selected from the Sloan Digital Sky Survey Data Release 2 (SDSS). The sample is unique in containing galax