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The GALEX Ultraviolet Atlas of Nearby Galaxies
We present images, integrated photometry, and surface-brightness andcolor profiles for a total of 1034 nearby galaxies recently observed bythe Galaxy Evolution Explorer (GALEX) satellite in its far-ultraviolet(FUV; λeff=1516 Å) and near-ultraviolet (NUV;λeff=2267 Å) bands. Our catalog of objects isderived primarily from the GALEX Nearby Galaxies Survey (NGS)supplemented by galaxies larger than 1' in diameter serendipitouslyfound in these fields and in other GALEX exposures of similar of greaterdepth. The sample analyzed here adequately describes the distributionand full range of properties (luminosity, color, star formation rate[SFR]) of galaxies in the local universe. From the surface brightnessprofiles obtained we have computed asymptotic magnitudes, colors, andluminosities, along with the concentration indices C31 and C42. We havealso morphologically classified the UV surface brightness profilesaccording to their shape. This data set has been complemented witharchival optical, near-infrared, and far-infrared fluxes and colors. Wefind that the integrated (FUV-K) color provides robust discriminationbetween elliptical and spiral/irregular galaxies and also among spiralgalaxies of different subtypes. Elliptical galaxies with brighter K-bandluminosities (i.e., more massive) are redder in (NUV-K) color but bluerin (FUV-NUV) (a color sensitive to the presence of a strong UV upturn)than less massive ellipticals. In the case of the spiral/irregulargalaxies our analysis shows the presence of a relatively tightcorrelation between the (FUV-NUV) color (or, equivalently, the slope ofthe UV spectrum, β) and the total infrared-to-UV ratio. Thecorrelation found between (FUV-NUV) color and K-band luminosity (withlower luminosity objects being bluer than more luminous ones) can beexplained as due to an increase in the dust content with galaxyluminosity. The images in this Atlas along with the profiles andintegrated properties are publicly available through a dedicated Webpage.
| Accurate Positions for MCG Galaxies
We have measured accurate celestial coordinates for 4741 extragalacticobjects, primarily drawn from a list of MCG galaxies with no recentlypublished accurate positions. The standard deviations in the newpositions depend slightly on the measurement method but are on the orderof 1.0" to 1.2". Standard deviations in the original MCG positions areconfirmed to be at the 1.5′-2.0′ level. These new positionswere integrated into NED in 1997 December.
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