Related papers: Why Are Some Optically Red Spirals NUV-r Blue?
arped disk galaxies are classified into two morphologies: S- and U-types. Conventional theories routinely attribute both types to galactic tidal interaction and/or gas accretion, but reproducing of U-types in simulations is extremely…
We report the discovery of a well-defined correlation between B-band face-on central optical depth due to dust, \tau^f_B, and the stellar mass surface density, \mu_{*}, of nearby (z < 0.13) spiral galaxies: log(\tau^f_B) =…
We make use of SHARDS, an ultra-deep (<26.5AB) galaxy survey that provides optical photo-spectra at resolution R~50, via medium band filters (FWHM~150A). This dataset is combined with ancillary optical and NIR fluxes to constrain the dust…
We perform radiation hydrodynamics simulations on the evolution of galactic gas disks irradiated by ultraviolet radiation background. We find gas disks with N_H > 10^21 cm^-2 exposed to ultraviolet radiation at a level of I_21=1 can be…
We have studied ~2100 early-type galaxies in the SDSS DR3 which have been detected by the GALEX Medium Imaging Survey (MIS), in the redshift range 0 < z < 0.11. Combining GALEX UV photometry with corollary optical data from the SDSS, we…
We present a detailed study of the colours in late-type galaxy discs for ten of the EDisCS galaxy clusters with 0.5 < z < 0.8. Our cluster sample contains 172 spiral galaxies, and our control sample is composed of 96 field disc galaxies. We…
We present the first results of an ongoing spectroscopic survey of galaxies selected in the rest-frame ultraviolet (UV). The redshift distribution extends over 0<z<0.5 and a high fraction of the sources show intense nebular emission lines…
Near-infrared (NIR) K' images of a sample of five low surface brightness disc galaxies (LSBGs) were combined with optical data, with the aim of constraining their star formation histories. Both red and blue LSBGs were imaged to enable…
We present preliminary results of a multi-wavelength study focused on the evolution of spiral galaxies in the UV-optical colour-magnitude (CM) diagram. By combining HI, UV and optical observations of the Coma-Abell1367 supercluster we are…
We constrain the spatial gradient of star formation history within galaxies using the colour gradients in NUV-u and u-i for a local spatially-resolved galaxy sample. By splitting each galaxy into an inner and an outer part, we find that…
The evolution of the Milky Way bulge and its relationship with the other Galactic populations is still poorly understood. The bulge has been suggested to be either a merger-driven classical bulge or the product of a dynamical instability of…
We combine GALEX (ultra-violet; UV) and SDSS (optical) photometry to study the recent star formation histories of ~100 field galaxies on the optical red sequence, a large fraction of which exhibit widespread signs of disturbed morphologies…
With a complete, mass-selected sample of quiescent galaxies from the NEWFIRM Medium-Band Survey (NMBS), we study the stellar populations of the oldest and most massive galaxies (>10^11 Msun) to high redshift. The sample includes 570…
We have used HRCam on the CFHT to obtain subarcsecond images of 26 galaxies with z=0.1--0.7. The primary sample of 17 galaxies have enhanced star formation indicated by [OII] equivalent widths greater than 20\AA, while the comparison sample…
How large disk galaxies have evolved in, and out of, the blue cloud of actively star-forming galaxies as a function of environment and time is an outstanding question. Some of the largest disks become systems like M31, M33 and the Milky Way…
We present a comparison of azimuthally averaged radial surface brightness mu(r) profiles and analytical bulge-disc decompositions (de Vaucouleurs, r^(1/4) bulge plus exponential disc) for spiral galaxies using Hubble Space…
The stellar and dust content of spiral galaxies as function of radius has been investigated using near-infrared and optical broadband surface photometry of 86 face-on spiral galaxies. Colors of galaxies correlate with the azimuthally…
We report on intriguing photometric properties of Galactic stars observed in the GALEX satellite's far-UV and near-UV bandbasses as well as from the SDSS survey and the Kepler Input Catalog. First, the FUV-NUV color distribution of stars in…
In this paper I review how near-infrared (NIR) observations can constrain the opacity of spiral disks. Basic considerations show that NIR photometry provides a powerful probe of the optical depths in spiral galaxy disks in the regime of…
Dust in galaxies can be mapped by either the FIR/sub-mm emission, the optical or infrared reddening of starlight, or the extinction of a known background source. We compare two dust extinction measurements for a set of fifteen sections in…