Interactions and star formation activity in Wolf-Rayet galaxies ґ Angel R. Lґ ez-Sґ hez1 and Cґ op anc esar Esteban 1 2 2 CSIRO ATNF, Australia Angel.Lopez-Sanchez@csiro.au Instituto de Astrofґ isica de Canarias, Spain, cel@iac.es We present some global results of the PhD Thesis carried out by Lґ ezop Sґ hez (2006), in which a detailed morphological, photometrical and spectrosanc copical analysis of a sample of 20 Wolf-Rayet (WR) galaxies was realized. ...

... A correlation between metal abundance and orbital elements (the eccentricity and angular momentum) has been found for three semples of disk stars of our Galaxy with abundance derived from detailed analysis. The correlation indicates that metal abundance in the Galaxy kept increasing after the birth of old disk stars and that the Galaxy kept collapsing during the formation of its disk subsystems. ...

... Spiral Galaxy NGC 3370 from Hubble . ... Is this what our own Milky Way Galaxy looks like from far away? Similar in size and grand design to our home Galaxy (although without the central bar), spiral galaxy NGC 3370 lies about 100 million light-years away toward the constellation of the Lion (Leo). ... The structure seen in the region of NGC 1999 in the Great Orion Molecular Cloud complex is one of the more mysterious structures yet found on the sky. ... Jupiter's Clouds from New Horizons . ...

... Editor's choices for the most educational Astronomy Pictures of the Day about spiral galaxies: . APOD: 2003 March 10 - M101: The Pinwheel Galaxy . Explanation: Why do many galaxies appear as spirals ? ... One result is that M101 , also called the Pinwheel Galaxy , has several extremely bright star-forming regions (called HII regions ) spread across its spiral arms. ... APOD: 2003 April 13 - NGC 1365: A Nearby Barred Spiral Galaxy . ... NGC 1365 is a member of the Fornax Cluster of Galaxies . ...

... Pustilnik S.A. - Ugryumov A.V. Two new blue compact (or HII) galaxies HS 1013+3809 and HS 1442+4250 were discovered in course of the Hamburg/SAO survey for emission-line galaxies. Both these very metal-deficient galaxies (log(O/H)+12.0 = 7.58 for HS 1013+3809 and 7.68 for HS 1442+4250) are comparatively bright and very nearby, and thus are good laboratories for detailed study of star formation bursts and related processes in very low metallicity environment. ...

... What are their star formation histories? How does this relate to galaxy populations at higher redshift? What, if anything, do we know about the star formation histories of galaxies at high-z? Do low mass and high mass galaxies evolve differently? Can we find a population of galaxies at low redshift which might correspond to a higher redshift population, i.e. the faint blue galaxies? ... What roles do bursts of star formation have in the evolution of dwarf galaxies? ...

... Are HVCs a common feature of star forming galaxies? ... Consider the typical properties of the smallest HVCs (compact HVCs) found in HIPASS: . Distance . HI Mass . ... At 5 kpc . meager objects ~116 solar masses . ... 1.15 x 10 4 solar masses . ... Putman et al. (2003) found none to 10 7 solar masses. 2% of Sculptor to 3 x 10 6 solar masses by de Blok et al. (2001) found none. ... High velocity gas around other galaxies can be identified from maps and dynamics: . ... 2003) . ...

... Galaxy Evolution home . ... Regulating the ISM and star formation . Cosmological evolution of star-forming galaxies . ... Local Information . ... In order to investigate the cosmological evolution of star-forming galaxies it is essential that we understand the physics which controls the evolution and regulation of star formation in the ISM. ... We use a combined observational and numerical approach to study interacting and merging galaxies in the local Universe. ...

... Contacts . 2012: . ... We refined the fundamental parameters of the components, the orbital periods, and the conditi