Space Mission Suzaku

Suzaku is an orbiting laboratory launched in 2005 by the Japanese Aerospace Exploration Agency (JAXA). Outfitted with the most advanced equipment ever developed for examining the X-ray spectrum of space, Suzaku has already yielded surprising insights about our universe.

 

The equipment jointly developed by NASA and the Japanese Institute for Space and Astronautical Science includes:

The universe is full of energy being emitted from countless sources, some of which is energy left over from the Big Bang. This energy exists across the full spectrum from low-energy radio waves to very high-energy gamma rays. With in this range of energy are lower energy visible light waves and higher energy X-rays.

 

In faraway galaxies, extremely hot gases (with temperatures over millions of degrees) are constantly emitting X-rays. Looking at these galaxies with special telescopes gives us some clue as to the types of ultra-hot materials within them, furthering our understanding of black holes, supernova and how energy particles come together to form galaxies.

 

X-ray emitting objects in space include:

 

Interestingly, some areas of space that appear to emit very little light are actually emitting spectacular amounts of X-rays. Seen through an X-ray telescope, these dark regions appear very "bright," cluing researchers into the fact that active energy in these regions requires closer study.

 

Specific chemical elements also display a distinctive X-ray signature, allowing us to determine the elemental makeup of the clouds of material surrounding and in between stars and galaxies. Knowing that certain types of supernova produce more oxygen than iron helps researchers use X-ray observations to determine what kind of explosion happened in a particular galaxy.

Suzaku is the sixth JAXA orbiting X-ray telescope. The first four Japanese X-ray astronomy satellites include:

On Feb. 10, 2000, Japan launched its fifth satellite in this series, ASTRO-E, only to watch it drop into the ocean after a second stage rocket failure. Its replacement, ASTRO-E2, was not launched until July 10, 2005.

 

Traditionally, the Japanese rename their missions after a successful launch. Thus ASTRO-E2 was re-christened Suzaku, meaning "red bird of the south."

 

Barely 40 days after launch, however, Suzaku started experiencing trouble. Liquid helium used to super cool the X-ray spectrometer (XRS) began leaking. Ten days later, all the helium had boiled off into space, and the XRS was inoperative. Yet, the other instruments, the four X-ray imaging spectrometers and the hard X-ray detector, as well as the five telescopes, are still functioning and delivering hard scientific data.

Despite the unexpected leak that eventually brought down the XRS, in the first days, the Suzaku's cooling system established the record for the coldest temperature ever created by human technology, 0.060 kelvin. Zero kelvin (approximately -460°F) is absolute zero, the temperature at which all atomic motion supposedly stops. Amazingly, Suzaku's cooling system came within 60 milli-degrees of absolute zero.

 

Suzaku's X-ray imaging spectrometer (XIS), which doesn't rely on the cooling system to work, uses a special megapixel CCD camera to collect X-ray images of space. Suzaku has four XISs on board, each with its own individual telescope to focus X-rays on its camera. While the XIS is not as sensitive as the XRS, it does cover a wider field of view.

 

High-energy X-rays (hard X-rays) are too powerful to be focused by telescope lenses. To "see" these rays, Suzaku's hard X-ray detector uses 16 tubes in the same way you would use a cardboard paper towel tube to look at a faraway object in visible light. The tube screens out photons not coming directly from the source you're looking at.

 

Although some X-ray photons still manage to enter the tubes at an angle, the device's computers are able to detect and discard their data, resulting in the highest sensitivity detector ever produced for X-rays in this high-energy range.

Using both Suzaku and the joint NASA – European Space Agency orbiting laboratory XMM-Newton, scientists have observed for the first time the space-time distortion caused by the incredible gravity of a neutron star. The discovery is based on the spectral shift of the X-ray signature of iron, similar to the Doppler shift that occurs when waves are moving rapidly toward or away from the observer.

 

The spectral shift observed is consistent with Einstein's theory of relativity, allowing scientists to estimate the size and density of the neutron star in Serpens X-1. Estimates project that Serpens X-1 weighs 400 times the density of our own sun.

 

Moreover, scientists are discovering that the shift in iron's X-ray signature allows them to determine much more about the properties of faraway celestial objects. Though no light escapes a black hole's immense gravity, X-rays in certain high-energy bands do escape and can be measured by Suzaku. These measurements are providing virtual images of the matter swirling around black holes that would be impossible to detect with ordinary telescopes.

 

 

National Aeronautics and Space Administration (2007). Astro-E2/Suzaku. Retrieved Feb. 6, 2008, from the NASA Web site.
 
National Aeronautics and Space Administration (n.d.). Suzaku Learning Center. Retrieved Feb. 6, 2008, from the NASA Web site.
 
European Space Agency (2007). XMM-Newton and Suzaku Help Pioneer Method for Probing Exotic Matter. Retrieved Feb. 6, 2008, from the Space and Aeronautics News Web site.
 
National Aeronautics and Space Administration (2006). Scientists Nudge Closer to the Edge of a Black Hole. Retrieved Feb 6, 2008, from the NASA Web site.