Abell 222
From Wikipedia, the free encyclopedia
| Abell 222 | |
|---|---|
 A portion of Abell 222 imaged by Legacy Surveys | |
| Observation data (Epoch J2000) | |
| Constellation(s) | Cetus |
| Right ascension | 01h 37m 27.4s[1] |
| Declination | −12° 58′ 45″[1] |
| Brightest member | LEDA 944643[2] |
| Richness class | 3[3] |
| Bautz–Morgan classification | II-III[3] |
| Velocity dispersion | 1,014 km/s[4] |
| Redshift | 0.2110[5] |
| Distance | 2.4 Gly (740 Mpc)[6] |
| ICM temperature | 3.77 ± 0.15 keV[4] |
| Other designations | |
| RXC J0137.4-1259[1] | |
Abell 222 is a galaxy cluster in the constellation of Cetus. It holds thousands of galaxies together. It is located at a distance of 2.4 billion light-years from Earth.[6]
Astronomers noticed an invisible string of matter was warping spacetime between Abell 222 and Abell 223. Upon further examination by using images from the Japanese Subaru telescope, astronomers discovered that this "invisible matter" is in fact dark matter. The astronomers used gravitational lensing to detect the dark matter filaments.[7] The cluster is connected by a filament of dark matter to Abell 223 that is permeated by hot X-ray emitting gas.[8] Further research shows that this filament only contains about 20 percent of normal matter, the rest is assumed to be dark matter. This is seen to be in good agreement with the cosmological standard model.[9] This means that the two bodies would form the Abell 222/Abell 223 Supercluster as defined by the IAU.[10]
