ultraviolet dropout

ultraviolet dropout

n.
1. The disappearance of an extremely distant galaxy from a telescope image when viewed through an ultraviolet filter, caused by the absorption of the galaxy's emitted ultraviolet radiation by intergalactic hydrogen gas.
2. A technique that identifies galaxies as extremely distant by comparing images taken through visible light (in which distant objects are often detectable) and ultraviolet filters (in which they are not).
References in periodicals archive ?
In contrast, the ultraviolet dropout technique relies on emissions over a broad range of colors.
In a cursory examination of the Hubble Deep Field, he and Dickinson independently applied the same ultraviolet dropout technique.
To spot these "ultraviolet dropouts," the astronomers would have to compare images of galaxies taken in a variety of colors, ranging from the red to the near ultraviolet.
With the help of this effect, known as ultraviolet dropout, Dickinson hopes to determine whether a number of bizarre, stringlike galaxies, also noted in another Hubble image, are truly distant (SN: 7/29/95, p.
Working at Keck Observatory, Steidel went on to get redshifts for some of his ultraviolet dropouts, which indeed were at cosmological distances.