Feature:Linux and X-Ray Astronomy

Kevin Remhof has submitted us a piece on an area of Linux that a lot of you might not be familiar with, but may wish to be: Linux and X-Ray Astronomy. Talks about some of the things you can do, as well as common applications to do them with. Check it out. The following was written by Slashdot Reader Kevin Linux and X-Ray Astronomy

by Kevin Remhof

On July 23, 1999, NASA deployed the Chandra X-Ray observatory from the Space Shuttle Columbia. This telescope is a major leap forward in X-Ray astronomy. It will enable scientists to study dark matter, black holes, and other objects with great detail. I was checking out the information on the Chandra website and started to wonder about the software behind this telescope. So, I did a little searching on NASA'as website and found some interesting information. What I found is that X-Ray Astronomy is depending more and more on Linux for analyzing the data.

Background

X-Ray astronomy has been around since the early days of the space program. X-Ray telescopes work much the same as a regular telescope, but rely on X-Rays to view objects. The earth?s atmosphere absorbs most radiation from space. So, in order to use these telescopes, they have to be lifted out of earth?s atmosphere. The first X-Ray telescope sent into space took pictures of the Sun. Since the Sun is so close to earth, it was not hard to focus this crude telescope. Modern X-Ray telescopes are much more refined. The Chandra telescope could read the letters on a stop sign from 12 miles away.

X-Ray telescope data needs to be decoded before it is useful. This is similar to the concepts behind the SETI@Home project. Astronomers are allocated time to use the telescope. Chandra has about a 55 minute viewing time during each or bit around the earth. The telescope first gathers data without interpreting it. That data is then transferred to earth. Scientists then pick up chunks of that data for analysis. It is then that the power of X-Ray telescopes can be seen. X-Ray pictures are a little strange. Although attractive pieces of art, they are not easily understood by the general public.

The Linux Connection

Astronomers have used UNIX as their standard platform for years. Sun, HP, DE C/OSF were all commonplace. That is until Linux came along. Linux is becoming more and more popular and is threatening to take over as the platform of choice. Linux is now the darling of NASA. It is easy to powerful, easy to use, and porting applications from UNIX is not too difficult. NASA even uses Beowulf clusters for various projects which need large amounts of computing power.

Linux is a great choice for X-Ray astronomy because of the wide available of the OS and the software for it. Two popular programs are XANADU and FTOOLS. Both of them began as UNIX programs and have now been ported to Linux.

One astronomer, Ken Ebisawa has even written a HOWTO on "Linux for X-Ray Astronomers ". He details how to get Linux up and running and some of the various tools useful in X-Ray astronomy. According to the Goddard Space Center?s website, & quot;Ebisawa hopes to resolve the mystery of the Milky Way's so-called diffuse X-ray emission, a ubiquitous cloud of X-rays that blankets our galactic plane and whose origin is unknown. To do so, Dr. Ebisawa will look at a region of space where this cloud varies in X-ray brightness but where there seems to be no distinct energy sources to produce it." Ebisawa will use his Dell Inspiron laptop to analyze his data.

Open Source Software

The latest development in X-Ray astronomy is Open Source. Another program for analyzing X-Ray data is called SAOimage. Currently, it is being redesigned and updated using Open Source practices. Open Source is a natural for this because users often want to extend the software by combining it with other systems to come up with a research environment. It also helps to reduce some of the costs associated with development of such complex systems. Using the bazaar model of software development allows multiple developers to maintain and upgrade this complex code. It also allows the shared development of key pieces of code and functionality while satisfying individual needs of users.

Conclusion

Linux is rapidly becoming the OS of choice for X-Ray astronomers. This is yet another credit to the flexibility and power of Linux. More information on the Chandra scientists can be found here.