Engineering topics

Wu, Xiaoyi

Publications and source records attributed to Wu, Xiaoyi.

3 records

NASA NTRS1995

A catalog of far-ultraviolet point sources detected with the fast FAUST Telescope on ATLAS-1

We list the photometric measurements of point sources made by the Far Ultraviolet Space Telescope (FAUST) when it flew on the ATLAS-1 space shuttle mission. The list contains 4698 Galactic and extragalactic objects detected in 22 wide-field images of the sky. At the locations surveyed, this catalog reaches a limiting magnitude approximately a factor of 10 fainter than the previous UV all-sky survey, TDl. The catalog limit is approximately 1 x 10(exp -14) ergs A sq cm/s, although it is not complete to this level. We list for each object the position, FUV flux, the error in flux, and where possible an identification from catalogs of nearby stars and galaxies. These catalogs include the Michigan HD (MHD) and HD, SAO, the HIPPARCOS Input Catalog, the Position and Proper Motion Catalog, the TD1 Catalog, the McCook and Sion Catalog of white dwarfs, and the RC3 Catalog of Galaxies. We identify 2239 FAUST sources with objects in the stellar catalogs and 172 with galaxies in the RC3 catalog. We estimate the number of sources with incorrect identifications to be less than 2%.

Bowyer, Stuart↗

NASA NTRS1993

A study of the impact of the Space Shuttle environment on faint far-UV geophysical and astronomical phenomena

FAUST is a far ultraviolet (1400-1800 A) photon-counting imaging telescope featuring a wide field of view (7.6 deg) and a high sensitivity to extended emission features. During its flight as part of the ATLAS-1 payload aboard the STS-45 mission in March 1992, 19 deep-space nighttime viewing opportunities were utilized by FAUST. Here we report the observed fluxes and their time and space variations, and identify the signatures of postsunset airglow phenomena and Orbiter Vernier attitude control thruster firing events. We find that the Space Shuttle nighttime environment at 296 km altitude is often sufficiently dark to permit geophysical and astronomical UV observations down to levels on the order of 1000 photons/sq cm sr A sec, or 0.01 Rayleighs/A. We also find evidence for occasional geophysical fluxes of some tens or hundreds of Rayleighs in the upward-looking direction.

Lampton, Michael↗

NASA NTRS1992

A comprehensive X-ray study of the Small Magellanic Cloud

A comprehensive analysis of the Einstein data base on the SMC is presented. Twenty-four soures are classified as objects in the SMC, and 13 as Galactic stars, AGN, and clusters of galaxies. The detected discrete emitters account for less than half of the excess emission associated with the SMC. The extensive diffuse emission has an X-ray spectrum substantially softer than that of the discrete sources, which is consistent with the presence of X-ray-emitting coronal gas associated with the SMC. A detailed study of the discrete sources is presented. An X-ray source is found to vary in its X-ray luminosity by a factor larger than 10 over a period of about 1 yr and has a relatively hard X-ray spectrum which apparently changes with the X-ray luminosity. It is suggested that this source, associated with a B1-type star, is a new high-mass X-ray binary in the Small Cloud.

Wang, Qingde↗