Diffuse gamma ray emission from the Galactic center at 2-3 GeV, as well as the 12 TeV gamma ray excess in the Galactic disk, remain open for debate and represent the missing puzzles in the complete picture of the high-energy Milky Way sky. Our papers emphasize the importance of understanding all of the populations that contribute to the diffuse gamma background in order to discriminate between the astrophysical sources such as supernova remnants and pulsars, and something that is expected to be seen in gamma rays and is much more exotic-dark matter. We analyze two separate data sets that have been measured in different energy ranges from the "Fermi-LAT" and "Milagro" telescopes, using these as a powerful tool to limit and test our analytical source population models. We model supernova remnants and pulsars, estimating the number of still undetected ones that contribute to the diffuse background, trying to explain both the Galactic center and the 12 TeV excess. Furthermore, we aim to predict the number of soon to be detected sources with new telescopes, such as the "HAWC".

Far infrared-radio correlation represents a linear relationship between far-infrared (FIR) and radio emission in star-forming galaxies. Previous observations have confirmed that this correlation is maintained over a large range of redshift and does not evolve, although a small dispersion is present. However, some of more recent observations at high redshift have shown the opposite. The question that arises is-what is driving this evolution? In this paper we investigate the possibility that galaxy morphology is the answer to this question. A sample of 37 submillimeter galaxies (SMGs) is analyzed. The observation and morphological class of these galaxies has previously been published. We examined FIR-radio correlation in galaxies of different morphological type in this sample and found that for star-forming disk galaxies correlation is stable and does not evolve and for irregular and interacting galaxies we find some hints of evolution.

Irregular galaxies are considered to be results of collisions or close approaches between galaxies. In the local universe, determining the morphological type and collision stage does not pose a problem. However, when it comes to galaxies at high redshifts, determining morphology is non-trivial. In this paper, the morphological parameters used to determine the morphology of galaxies at large redshifts will be summarised and described in detail. The aim of this research is to examine the sensitivity of morphological parameters at different collision stages on galaxies in the Local Universe, so that the most sensitive parameter can be found and later applied to the study of collisions between distant galaxies.