ASCA's Significant Contributions to Astrophysics
Welcome to ASCA's Significant Contributions to Astrophysics. Our aim is to present an overview of the variety of important scientific results obtained with the ASCA satellite, suitable to non-specialists. Introductory materials on this page in particular are geared toward the general public. More technical descriptions of the science can be found in the two sets of "Science Highlights" texts that were prepared for the NASA astrophysics senior review.
ASCA (Advanced Satellite for Cosmology and Astrophysics; read more about this name) was launched by ISAS (Institute of Space and Astronautical Sciences), Japan, on February 20, 1993, and reentered the Earth's atmosphere on March 2, 2001, having spent more than 8 years in orbit. During the mission lifetime, ASCA performed over 3000 observations, and produced over 1000 publications in refereed journals so far. Although the ASCA archive contain plenty of data for future analyses, we would like to celebrate the completion of a highly successful mission by reflecting on what scientists in many counties have accomplished using ASCA data so far.
The US has contributed significantly to ASCA's scientific payloads. In return, 40% of ASCA observing time was made available to US scientists. (ISAS also opened up 10% of the time to ESA scientists as a good-will gesture.) In addition, all ASCA data enter the public domain after a suitable period (1 year for US data, 18 months for Japanese data) and become available to scientists worldwide. The design of ASCA was optimized for X-ray spectroscopy; thus it complimented ROSAT (optimized for X-ray imaging) and RXTE (optimized for timing studies).
ASCA results cover almost the entire range of objects, from nearby stars to the most distant objects in the universe. They involve important themes such as
- How were elements created and distributed (supernova remnants, clusters of galaxies)?
- What happens to matter in extreme gravities around a black hole (X-ray binaries, active galactic nuclei)?
- Can we learn about how matter is heated to X-ray temperatures (stars, cataclysmic variables)?
We have a collection of images with captions for many of the important scientific results obtained with ASCA. We have created an explanatory page for each of eight broad scientific categories. These pages contain a short description to give you the context of these discoveries, as well as links to the actual images with captions.
|X-ray Binaries||Supernova Remnants|
|Normal Galaxies||Active Galactic Nuclei|
|Clusters of Galaxies||Surveys|
This page created by Dr. Koji Mukai (USRA) at the U.S. ASCA Guest Observer Facility.
If you have any questions concerning ASCA, visit our Feedback form.