Chandra X-ray observing telescope celebrates 10th anniversary

WASHINGTON - The Chandra X-ray observing telescope is celebrating ten years of its launch, during which it has made a number of significant achievements.

NASA launched its Chandra X-ray observing telescope into orbit in 1999.

During that time, astronomers didn’t know much about the galactic winds made of wispy, multi-million-degree gas clouds that stream out from normal galaxies like our own, because they are “diffuse, gentle and unspectacular” compared to far more dramatic emanations of starbursts.

But direct observation by the Chandra orbiting telescope have changed all that and led to “the first characterization of the spatial, thermal, chemical and kinetic properties of the gas in our galaxy,” Wang stated.

Chandra data show, among other things, that though seemingly as ephemeral as fog, the outflowing hot gas from normal galaxies exerts a very powerful feedback force on the surroundings, preventing or slowing the infall of intergalactic gas due to gravity.
This discovery is a new key to our understanding of how galaxies work, especially how they lose mass and energy, that was not possible before Chandra,” said Wang.

According to Wang, galaxies like our own are made of visible stars and gas but investigating this matter and its properties using only visible light reveals only a small fraction of material actually present.

“The hot gas is very hard to detect because of its low density, hence weak radiation, compared to black holes and neutron stars that accrete from their companions, which tend to overwhelm X-ray emissions from a galaxy,” he said.

“By X-raying galaxies, we can see the invisible, and with the Chandra instrument we can detect gas that emits or absorbs X-rays, as well as such exotic objects as black holes and neutron stars that tend to emit primarily in X-rays,” he added.

X-ray tomography by the high-spectral resolution Chandra instrument has given astronomers the unprecedented opportunity to examine the amount, distribution and composition of the hot gas against bright background sources.

It has also helped to yield clues to the mystery of why there is not enough hot gas present inside or in the immediate vicinity of galaxies as predicted by current theory, in particular elements ynthesized and ejected by stars. (ANI)