The Chandra X-ray Observatory is the U.S. follow-on to the Einstein
Observatory. Chandra was formerly known as AXAF, the Advanced X-ray
Astrophysics Facility, but renamed by NASA in December, 1998.
Originally three instruments and a high-resolution mirror carried in
one spacecraft, the project was reworked in 1992 and 1993. The Chandra
spacecraft carries a high resolution mirror, two imaging detectors,
and two sets of transmission gratings. Important Chandra features are:
an order of magnitude improvement in spatial resolution, good
sensitivity from 0.1 to 10 keV, and the capability for high spectral
resolution observations over most of this range.
High frequency water maser and HI spectra are available through this web service. The water maser phenomena are found in active galactic nuclei (AGN) and have been surveyed with the NRAO Green Bank Telescope. HI spectra are measured mostly from galaxies in the local Universe.
