There are about 100 million years, the two galaxies NGC 4038 and 4039 began to collide. This collision is still ongoing. NGC 4038 was a spiral galaxy, and NGC 4039, a barred spiral galaxy. They now form one of the most famous couples galaxy, called the Antennae. The tidal forces of the collision drew a shape resembling the antennae of an insect, hence the name. At the end of their merger, in about 400 million years, they will form a supergalaxy. They were discovered by William Herschel in 1785, the English name is "Ringtail Galaxy." This galaxy is located in the constellation of the Raven, it belongs to NGC 4038 with 5 other galaxies. In 2004 and 2005, the Hubble telescope, with its new high-resolution camera ACS photographed the shock cosmic runs at 62 million light years from our Galaxy. The photo shows with unprecedented clarity the many regions of star formation (pink and blue in the image), appeared after the compression of interstellar gas, generated by gravitational encounters. Already in 1997, the Space Telescope had photographed the central part of the antenna. But this time, astronomers are able to give details of giant star clusters, one hundred of them only should survive as globular clusters.
Gravitational encounters between stars are very rare. Slow collisions of galaxies, carried out on tens of millions of years, but they are violent. The gravitational interactions of galaxies in collision, generate huge shock waves in the surrounding gas and dust. This shock wave causes the formation of massive stars in the millions. These massive stars have a short life that ends in explosion. These are supernovae that enrich the interstellar medium in heavy atoms (beyond iron).
Image: Cosmic catastrophe in the form of galactic collision. There are about 100 million years, the two galaxies NGC 4038 and 4039 began to collide. This pair of galaxies is called the "Galaxy antennas." It is a perfect case for creating supergalaxy, that was before our eyes, thanks to the Hubble telescope. Hubble images of high resolution ESA.
nota: ACS high-resolution camera, low light, was replaced at the last visit to Hubble in 2002 by an advanced camera for Surveys (ACS, Advanced Camera for Surveys).
Antennae seen by Hubble, Chandra and Spitzer
A new image of two colliding galaxies, NGC 4038 and 4039, was captured by NASA's Great Observatories. The Antennae Galaxies are represented here in a composite of three telescopes. Those of the Chandra X-ray Observatory (blue colors), the Hubble Space Telescope (gold color) and the Spitzer Space Telescope (red colors). The collision, which began over 100 million years ago triggered the ongoing training of millions of stars in the clouds of dust and gas of the galaxies. The most massive of these young stars explode as supernovae. The X-ray image from Chandra shows huge clouds of interstellar hot gas ejected by supernova explosions. This enriched gas, which includes elements such as oxygen, iron, magnesium and silicon, will be incorporated in new generations of stars and planets.
Video: The bright point sources in the image are produced by matter falling into black holes and neutron stars, the remnants of massive stars. The Spitzer data show infrared light after clouds of dust heated by young stars located in the region of overlap between the two galaxies. The Hubble data show in red, old stars, brown dust filaments and yellow and white, star-forming regions. Objects whose brightness is lower in the optical image are clusters containing thousands of stars. These features were produced by tidal forces generated by the collision. Credits: X-ray: NASA / CXC / SAO / J. DePasquale, IR: NASA / JPL-Caltech; Optical: NASA / STScI