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We combine high-resolution images from GEMS with redshifts and spectral energy distributions from COMBO-17 to explore the morphological types of galaxies that dominate the z~0.7 UV luminosity density. We analysed rest-frame 280 nm and V-band luminosities of 1483 galaxies with 0.65<z< 0.75, combining these with visual morphological classifications from F850LP images (approximately rest-frame V-band) taken with HST/ACS on the Extended Chandra Deep Field South. We derive UV luminosity functions and j_280 luminosity densities for spheroid-dominated galaxies, spiral galaxies, Magellanic irregulars, and clearly-interacting galaxies with morphologies suggestive of ongoing major mergers. We check the reliability of GEMS morphologies against the deeper GOODS images and quantify an incompleteness of the GEMS merger identification at the faint end. We derive the fractions of the global UV luminosity density j_280 originating from the galaxy types, and find that spiral galaxies and Magellanic irregulars dominate with about 40% each. Interacting and merging galaxies account for roughly 20% of j_280, while the contribution of early types is negligible. These results imply that the strong decline in the UV luminosity density of the Universe observed from z~1 until today is dominated by the decreasing UV luminosities of normal spiral galaxies, accompanied by the migration of UV-luminous star formation in irregular galaxies to systems of progressively lower mass and luminosity. (abridged)
We study the contribution of galaxies with different properties to the global densities of star formation rate (SFR), atomic (HI) and molecular hydrogen (H2) as a function of redshift. We use the GALFORM model of galaxy formation, which is set in the
Despite a mounting evidence that the same gradients which active colloids use for swimming, induce important cross-interactions (phoretic interaction), they are still ignored in most many-body descriptions, perhaps to avoid complexity and a zoo of un
The deposition of mechanical feedback from a supermassive black hole (SMBH) in an active galactic nucleus (AGN) into the surrounding galaxy occurs via broad-line winds which must carry mass and radial momentum as well as energy. The effect can be sum
We identified the z~2 Lyman break galaxies using deep HST ultraviolet (F275W/F336W) imaging of Abell 1689. Because of the imaging depth and the large magnification provided by the cluster, we detect galaxies 100x fainter (-19.5< M_1500 <-13) than pre
Previous optical studies found an unexpected deficit of bars at z > 0.7. To investigate the effects of bandshifting, we have studied the fraction of barred spirals in the NICMOS Deep Field North. At z > 0.7 we find at least four barred spirals, doubl