| Abell 2218 | |
|---|---|
 | |
| Observation data (Epoch J2000) | |
| Constellation(s) | Draco |
| Right ascension | 16h 35m 54s[1] |
| Declination | +66° 13′ 00″[1] |
| Number of galaxies | ~10,000 |
| Richness class | 4[2] |
| Bautz–Morgan classification | II [2] |
| Redshift | 0.17560[1] |
| Distance | 719 Mpc (2,345 Mly) h−1 0.705[1] |
| X-ray flux | (7.50 ± 9.1%)×10−12 erg s−1 cm−2 (0.1–2.4 keV) [1] |
Abell 2218 is a large cluster of galaxies over 2 billion light-years away in the constellation Draco.
Acting as a powerful lens, it magnifies and distorts all galaxies lying behind the cluster core into long arcs. The lensed galaxies are all stretched along the cluster's center and some of them are multiply imaged. Those multiple images usually appear as a pair of images with a third — generally fainter — counter image, as is the case for the very distant object. The lensed galaxies are particularly numerous, as we are looking in between two mass clumps, in a saddle region where the magnification is quite large.
- ^ a b c d e "NASA/IPAC Extragalactic Database". Results for Abell 2218. Retrieved 2006-09-18.
- ^ a b Abell, George O.; Corwin, Harold G. Jr.; Olowin, Ronald P. (May 1989). "A catalog of rich clusters of galaxies". Astrophysical Journal Supplement Series. 70 (May 1989): 1–138. Bibcode:1989ApJS...70....1A. doi:10.1086/191333. ISSN 0067-0049.