NGC 7318

From Wikipedia, the free encyclopedia

Observation data (J2000 epoch)
NGC 7318
HGC 92. 8-micrometre infrared light = red, H-alpha = green, visible red light = blue
Constellation	Pegasus
Right ascension	22^h 35^m 56.7^s / 22^h 35^m 58.4^s^[1]
Declination	+33° 57′ 56″ / +33° 57′ 57″^[1]
Redshift	6630 ± 23 / 5774 ± 24 km/s^[1]
Distance	300 Mly^{[citation needed]}
Type	E2 pec / SB(s)bc pec^[1]
Apparent dimensions (V)	0′.9 × 0′.9 / 1′.9 × 1′.2^[1]
Apparent magnitude (V)	14.4 / 13.9^[1]
Notable features	Colliding galaxies
Other designations
NGC 7318a / 7318b,^[1] UGC 12099 / 12100,^[1] Arp 319,^[1] PGC 69260 / 69263,^[1] HCG 92d / 92b^[1]
See also: Galaxy, List of galaxies

NGC 7318 (also known as UGC 12099/UGC 12100 or HCG 92d/b) are a set of galaxies about 300 million light-years away in the Constellation Pegasus. They are a member of the famous Stephan's Quintet, these galaxies are in the process of colliding.

The Spitzer Space Telescope revealed the presence of a huge intergalactic shock wave, shown by the magnificent green arc in the picture at right produced by one galaxy falling into another at millions of miles per hour. As NGC 7318B collides with NGC 7318A, gas spread throughout the cluster, atoms of hydrogen are heated in the shock wave, producing the green glow. The molecular hydrogen seen here is one of the most turbulent forms of molecular hydrogen ever seen. This phenomenon was discovered by an international team of scientists of the Max Planck Institute for Nuclear Physics (MPIK) in Heidelberg. Most notable is the fact that this collision can help provide a view into what happened in the early universe 10 billion years ago when it formed.