Документ взят из кэша поисковой машины. Адрес оригинального документа : http://www.arcetri.astro.it/~palla/ANDREAIMMAGINI/Galassie/Merging.txt Дата изменения: Sun Mar 4 18:57:44 2001 Дата индексирования: Sat Dec 22 08:37:56 2007 Кодировка: Поисковые слова: arp 220

EMBARGOED UNTIL: 9:00 a.m. (EDT) July 15, 1999

PHOTO NO.: STScI-PRC99-28

GALAXY COLLISIONS IN DISTANT CLUSTER

The group of galaxies -- or "galaxy cluster" -- catalogued as MS1054-03
is 8 billion light-years away, one of the most distant known so far.
Although hundreds of galaxies appear in the NASA/ESA Hubble Space
Telescope image, a European-led team of astronomers has studied in
detail 81 galaxies that certainly belong to the cluster, 13 of which are
remnants of recent collisions or pairs of colliding galaxies. This is by
far the largest number of colliding galaxies ever found in a cluster.

The picture is actually a "mosaic" of images, so that astronomers can
have a much wider view of the distant cluster. This is why the colliding
galaxies, mostly located in clumps in the outskirts of the cluster, had
not been discovered so far.

In the image, streams of stars can be seen being pulled out of the
galaxies, a consequence of the huge tidal forces in action. The red
color of most of the merger remnants means that the stars are old and
not much star formation has "recently" taken place.

The observations with the Hubble were made in May 1998. The 10-meter
Keck telescope in Hawaii was used to confirm that the colliding galaxies
were part of the cluster.

Photo Credits: Pieter van Dokkum, Marijn Franx (University of
Groningen/Leiden), ESA and NASA