Exploring the Invisible Universe - Chandra X-ray Telescope

The Chandra X-ray Observatory’s Imaging Spectrometer is also located at the narrow end of the observatory. This detector is capable of recording not only the position, but also the color (energy) of the X-rays. The imaging spectrometer is made up of 10 charge-coupled device arrays. These detectors are similar to those used in home video recorders and digital cameras but are designed to detect X-rays. Commands from the ground allow astronomers to select which of the various detectors to use. The imaging spectrometer can distinguish up to 50 different energies within the range the observatory operates. In order to gain even more energy information, two screen-like instruments, called diffraction gratings, can be inserted into the path of the X-rays between the telescope and the detectors. The gratings change the path of the X-ray depending on its color (energy) and the X-ray cameras record the color and position. One grating concentrates on the higher and medium energies and uses the imaging spectrometer as a detector – the other grating disperses low energies and is used in conjunction with the High Resolution Camera.

To the "eye" of an X-ray telescope, the Universe is totally different – a violent, vibrant, and ever-changing place. Temperatures can reach millions of degrees. Objects are accelerated by gravity to nearly the speed of light and magnetic fields more than a trillion times stronger than the Earth’s cause some stars to crack and tremble.

NASA’s newest space telescope, called the Chandra X-ray Observatory, will allow scientists from around the world to obtain unprecedented X-ray images of these and other exotic environments to help understand the structure and evolution of the Universe. The observatory will not only help to probe these mysteries, but also will serve as a unique tool to study detailed physics in a laboratory that cannot be replicated here on Earth – the Universe itself. NASA’s Chandra X-ray Observatory has every prospect of rewriting textbooks and helping technology advance in the coming decade.

The Chandra X-ray Observatory will provide unique and crucial information on the nature of objects ranging from comets in our Solar System to quasars at the edge of the observable Universe. The observatory should provide long-sought answers to some major scientific questions, such as what and where is the "Dark Matter" in our Universe? The largest and most massive objects in the Universe are galaxy clusters - enormous collections of galaxies, some like our own. These galaxies are bound together into a cluster by gravity. Much of their mass is in the form of an incredibly hot, X-ray emitting gas that fills the entire space between the galaxies. Yet, neither the mass of the galaxies, nor the mass of the hot X-ray gas is enough to provide the gravity that we know holds the cluster together. X-ray observations with the Chandra X-ray Observatory will map the location of the dark matter and help us to identify it.