Updated June 01, 2013

X-ray Universe

Invisible universe

Invisible Universe, which can be called "Universe X" refers to the universe that it is not, contrary to that usually seen in the visible frequency range, corresponding to the colors of the rainbow sky. Optical or visible light, only a small range of electromagnetic vibrations found in the electromagnetic spectrum. But the light is spread over a larger electromagnetic field. Maxwell determined that light is an electromagnetic wave and there is no reason to limit the wavelength of the latter to the interval corresponding to the visible light spectrum, the spectrum is light (image shown against). On both sides of the visible light there is light invisible infrared and ultraviolet, X-rays, invisible, too, is more energy and are beyond the ultraviolet.
X-rays are electromagnetic waves with high frequency whose wavelength ranges, roughly, between 5 picometers and 10 nanometers. X-rays are produced in the cosmos when matter is heated to millions of degrees. These temperatures occur where there is, extremely powerful magnetic fields, or extremely serious. X-rays, unlike optical rays, have the distinction of not being absorbed or deflected by interstellar dust clouds. X-rays, unlike optical rays, have the distinction of not being absorbed or deflected by interstellar dust clouds. These latter are the main obstacles limiting the observation of the universe. The "X-ray Universe", corresponds to the universe we can observe with telescopes designed to detect X-rays and for that we must get rid of the air filter of our planet.

These telescopes have been placed in space. The X-ray telescope can detect, the hot gases from the explosion of a star or X-rays from matter swirling on the edge of a black hole. The Chandra X-ray Observatory, launched by the Space Shuttle Columbia July 23, 1999 and allows a better definition of hot, turbulent regions of space. It was named "Chandra" in honor of Subrahmanyan Chandrasekhar. Radio astronomers can since capture images of the sky in the range of X-rays and see the amazing phenomena, objects falling into black holes, exploding stars, galaxies colliding, huge clusters of galaxies that cross.
The cosmos we now reveal, hidden secrets behind each end of the spectrum with the two observation satellites X: the European satellite XMM-Newton and Chandra the American satellite.

Image: Electromagnetic spectrum includes all the windows of the light. X-rays are ultraviolet rays between and gamma waves. Their wavelengths are approximately between 5 picometers and 10 nanometers. With Hubble, Spitzer, Wise, XMM-Newton, Chandra and other satellites, astronomers can see the universe by combining the visual, infrared, radio and X-radiation.

X-rays and gravity

What structures are large enough and hot to emit X-rays?
X-rays are produced when the material is heated to millions of degrees. The detection of X-rays will reveal regions where magnetic fields are extremely powerful, or places where gravity is extreme. This is the case of Stephan's Quintet, a cluster of galaxies located in the constellation of Pegasus. Galaxies attract each other because of their strong gravity, and they eventually merge. We see in this image, distorted by the shapes of filaments that extend far from the center of the galaxy. The blue spots in the spiral arm to the right of the bar, are groups of several thousand stars, seen in the range of X-ray In the center of the image, the galaxy appears to have two hearts, but they are actually two galaxies, NGC 7318A and NGC 7318B. A bright clusters of young blue stars, less than 10 million years, being born, encircles these galaxies.

This cluster is also seen in the range of X-ray This cluster was discovered in 1877 by the French astronomer Edouard Stephan, from the observatory of Marseille.

Image: The 3598 ESO galaxy clusters or clusters of galaxies Stephan's Quintet is located near the constellation of Pegasus, the winged horse. This beautiful blue trail in the heart of the Quintet of the cluster is seen by the Chandra X-ray telescope. The blue path is due to the extreme warming of the surrounding gas by shock waves caused by the passage of the galaxy NGC 7318b among his neighbors (NGC 7317, NGC 7318a and NGC 7319).
Credit: NASA/CXC/CFa/CFHT/Coelum/C&EPhotos

X-rays and magnetic field

Remember that neutron stars, unlike planets and ordinary stars, have super powerful magnetic fields. The conditions inside the star, are extreme, and the magnetic field is so intense that it deforms to the atoms that make up matter.
In the absence of magnetic fields, the atoms have a spherical shape, while subjected to magnetic fields super powerful, they take a tapered shape and align themselves along lines of magnetic field, like so many small needles placed end to end.
The chemical atoms exert forces on each other, joining in the thin, long molecular chains.
The material takes a tapered structure in lock of hair.
This is the first critical phase of compression, it is the area of the surface of the star.

Image: Jets of matter and antimatter away from the neutron star at the center of the Crab Nebula.
This image in the X-ray was taken in 2002 by the Chandra satellite.
The central ring has a diameter of about one light year. Credit: NASA/CXC/ASU/J. Hester et al.

X-rays and wind energy

PSR B1509-58 is a relatively young pulsar because the light from the supernova that gave birth to have reached the Earth 1700 years ago.
This pulsar was first detected as X-ray source by the Uhuru satellite, then as a pulsating source by the Einstein satellite in 1982 and observed in radio.
His radio show is relatively low, its discovery in the radio would not have been possible without his prior discovery in the field of X-ray.
This neutron star of only 20 km in diameter, turns on itself seven times per second, this cosmic dynamo powers a wind of charged particles.
In this picture you can see the wind energy that generates X-rays of the nebula at the top of the image of the orbiting Chandra Observatory.

The low energy X-rays are colored red, intermediate energies in green and high energies in blue.
The pulsar itself is the heart of the bright central region at the bottom of the complex structure that irresistibly evokes an outstretched hand or glove.
PSR B1509-58 is located about 17,000 light-years away in the southern constellation of the compass.
At this distance, the Chandra image covers a field of 100 light-years wide.

Image: Credit: P. Slane (Harvard-Smithsonian CfA) et al., CXC, NASA

X-rays and black holes

This stunning composite image of Arp 147 shows two interacting galaxies, located about 430 million light years from Earth.
It consists of a set of images roses, taken in X-rays by Chandra X-ray and optical data (red, green, blue), the Hubble Space Telescope.
Arp 147 (right) contains the remains of a spiral galaxy, pierced by the collision with the elliptical galaxy on the left. The meeting left a wave of star stands today as a blue ring, hosting young massive stars.
In a few million years, these stars explode as supernovae, leaving behind neutron stars and black holes. The nine X-ray sources (pink), scattered around the blue ring in Arp 147 are so bright they could create black holes, ten to twenty times the mass of the sun.
An X-ray source is also visible in the nucleus of the galaxy rose from the center of the image.

This source could also be powered by a supermassive black hole.
Other objects, unrelated to Arp 147 are also visible on the image, especially in the background, above and left of the galaxy rose you can see, thanks to X-rays, the source of a red quasar.

Image: On this remarkable image of Arp 147, two galaxies have just been through and still interact with many black holes in training.
Credit: X-ray: NASA/CXC/MIT/S Rappaport et al., Optical: NASA/STScI

Tarantula X-rayed

2400 massive stars are hidden in the center of the Tarantula Nebula (30 Doradus).
These stars produce radiation so intense that the strong winds, blowing off the field. The gas of the nebula, heated to millions of degrees by shock waves stellar radiation, is shown in blue on the X-ray image taken by the Chandra X-ray Observatory. This shock wave is produced by the powerful winds and ultraviolet radiation emitted by young stars of the cluster. These explosions carve in the cloud of dust, huge bubbles of superheated gas, from the cold matter of the nebula. This cold material in orange, is represented here by infrared emission from the Spitzer Space Telescope. RMC 136, is the supercluster of stars near the center of the Tarantula Nebula. It is known as 30 Doradus.

Tarantula Nebula is outside of our galaxy, the Large Magellanic Cloud, at 170 000 light years from the solar system. At the heart of this region of star formation, 30 Doradus, is a gigantic star clusters containing the largest, most massive and hottest known to date.