When the newly developed near ultraviolet
LED is combined with the mixture of phosphor of the three primary colors (red/green/blue), it achieves high levels of color rendering property, enabling its use in general lighting.
This project will combine its results with those from earlier surveys to cover wavelengths from the near ultraviolet
(3000 angstroms) to the near infrared (2.2 microns).
Describing their new "superconducting tunnel junction" (STJ) in the May 9 Nature, the researchers explain that it can detect the position, arrival time, and energy of individual photons whose wavelengths measure as little as 200 to 500 nanometers-from near ultraviolet
to visible light.
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
. Steidel and his collaborators gathered such multiwavelength portraits at three observatories: the William Herschel Telescope in the Canary Islands, Spain, the Cerro Tololo Inter-American Observatory in La Serena, Chile, and Palomar Observatory near Escondido, Calif.
The Extreme Ultraviolet Explorer (EUVE), launched last June, detects this band of radiation, which can't penetrate Earth's atmosphere and is intermediate in energy between the near ultraviolet
and X-rays (SN: 5/23/92, p.344).
But orbiting 380 miles above Earth, the Hubble Space Telescope now reveals that the nucleus of NGC 3862 spews out a short jet of radiation, too short to have been detected with ground-based telescopes, in both visible light and the near ultraviolet
. Moreover, this jet shines more brightly in the ultraviolet -- at the shorter end of the electromagnetic spectrum -- than at longer wavelengths, a feature diametrically opposite to the energy output of any other galactic jet yet observed.