# Abell 2218

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Galaxy cluster in the constellation Draco

Abell 2218 Abell 2218. Credit: NASA/ESA Observation data (Epoch J2000) Constellation 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](/source/Galaxy_cluster) over [2 billion](/source/10_zettametres) [light-years](/source/Light-year) away in the [constellation](/source/Constellation) [Draco](/source/Draco_(constellation)).

Acting as a powerful [lens](/source/Gravitational_lens), it magnifies and distorts all galaxies lying behind the cluster core into long [arcs](/source/Arc_(geometry)). 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.

## Gravitational lensing

Abell 2218 was used as a gravitational lens to discover the most distant known object in the universe as of 2004. The object, a galaxy some 13 billion years old, is seen from Earth as it would have been just 750 million years after the [Big Bang](/source/Big_Bang).[3]

The [color](/source/Color) of the lensed galaxies is a function of their distances and types. The [orange](/source/Orange_(colour)) arc is an [elliptical galaxy](/source/Elliptical_galaxy) at moderate redshift (z=0.7). The [blue](/source/Blue) arcs are star-forming galaxies at intermediate redshift (z=1–2.5). There is a pair of images in the lower part of the picture of the newly discovered star-forming galaxy at about redshift 7.[4]

## Dark matter

Clusters of galaxies such as Abell 2218 have also been used to infer both the amount[5][6] and distribution[7][8][9] of [Dark matter](/source/Dark_matter).

## See also

- [Abell 370](/source/Abell_370)

- [Abell 1689](/source/Abell_1689)

- [Abell 1835 IR1916](/source/Abell_1835_IR1916)

- [Abell catalogue](/source/Abell_catalogue)

- [GRB 090423](/source/GRB_090423)

- [IOK-1](/source/IOK-1)

- [UDFy-38135539](/source/UDFy-38135539)

- [X-ray astronomy](/source/X-ray_astronomy)

## References

1. ^ [***a***](#cite_ref-NED_1-0) [***b***](#cite_ref-NED_1-1) [***c***](#cite_ref-NED_1-2) [***d***](#cite_ref-NED_1-3) [***e***](#cite_ref-NED_1-4) ["NASA/IPAC Extragalactic Database"](http://nedwww.ipac.caltech.edu/). *Results for Abell 2218*. Retrieved 2006-09-18.

1. ^ [***a***](#cite_ref-ACO_2-0) [***b***](#cite_ref-ACO_2-1) [Abell, George O.](/source/George_O._Abell); [Corwin, Harold G. Jr.](https://en.wikipedia.org/w/index.php?title=Harold_G._Corwin&action=edit&redlink=1); [Olowin, Ronald P.](https://en.wikipedia.org/w/index.php?title=Ronald_P._Olowin&action=edit&redlink=1) (May 1989). ["A catalog of rich clusters of galaxies"](https://doi.org/10.1086%2F191333). *Astrophysical Journal Supplement Series*. **70** (May 1989): 1–138. [Bibcode](/source/Bibcode_(identifier)):[1989ApJS...70....1A](https://ui.adsabs.harvard.edu/abs/1989ApJS...70....1A). [doi](/source/Doi_(identifier)):[10.1086/191333](https://doi.org/10.1086%2F191333). [ISSN](/source/ISSN_(identifier)) [0067-0049](https://search.worldcat.org/issn/0067-0049).

1. **[^](#cite_ref-3)** [NBC News: "Galaxy ranks as most distant object in cosmos"](https://web.archive.org/web/20140221090216/http://www.nbcnews.com/id/4274187/)

1. **[^](#cite_ref-4)** Kneib, Jean-Paul; Ellis, Richard S.; Santos, Michael R.; Richard, Johan (2004). "A Probable z~7 Galaxy Strongly Lensed by the Rich Cluster A2218: Exploring the Dark Ages". *The Astrophysical Journal*. **607** (2): 697–703. [arXiv](/source/ArXiv_(identifier)):[astro-ph/0402319](https://arxiv.org/abs/astro-ph/0402319). [Bibcode](/source/Bibcode_(identifier)):[2004ApJ...607..697K](https://ui.adsabs.harvard.edu/abs/2004ApJ...607..697K). [doi](/source/Doi_(identifier)):[10.1086/386281](https://doi.org/10.1086%2F386281). [S2CID](/source/S2CID_(identifier)) [14981473](https://api.semanticscholar.org/CorpusID:14981473).

1. **[^](#cite_ref-5)** Kneib, Jean-Paul (1995). "Dynamics of Abell 2218 from optical and near-IR imagery of arc(let)s and the Rosat/HRI X-ray map". *Astronomy and Astrophysics*. **303**: 27–40. [arXiv](/source/ArXiv_(identifier)):[astro-ph/9504038](https://arxiv.org/abs/astro-ph/9504038). [Bibcode](/source/Bibcode_(identifier)):[1995A&A...303...27K](https://ui.adsabs.harvard.edu/abs/1995A&A...303...27K).

1. **[^](#cite_ref-6)** Squires, G.; Kaiser, N.; Babul, A.; Fahlman, G.; Woods, D.; Neumann, D.; Böhringer, H. (1996). "The dark matter, gas, and galaxy distributions in Abell 2218: A weak gravitational lensing and X-ray analysis". *The Astrophysical Journal*. **461**: 572–586. [arXiv](/source/ArXiv_(identifier)):[astro-ph/9507008](https://arxiv.org/abs/astro-ph/9507008). [Bibcode](/source/Bibcode_(identifier)):[1996ApJ...461..572S](https://ui.adsabs.harvard.edu/abs/1996ApJ...461..572S). [doi](/source/Doi_(identifier)):[10.1086/177085](https://doi.org/10.1086%2F177085). [S2CID](/source/S2CID_(identifier)) [18973537](https://api.semanticscholar.org/CorpusID:18973537).

1. **[^](#cite_ref-7)** Abdelsalam, Hanadi M.; Saha, Prasenjit; Williams, Liliya L. R. (1998). "Non-parametric reconstruction of Abell 2218 from combined weak and strong lensing". *The Astronomical Journal*. **116** (4): 1541–1552. [arXiv](/source/ArXiv_(identifier)):[astro-ph/9806244](https://arxiv.org/abs/astro-ph/9806244). [Bibcode](/source/Bibcode_(identifier)):[1998AJ....116.1541A](https://ui.adsabs.harvard.edu/abs/1998AJ....116.1541A). [doi](/source/Doi_(identifier)):[10.1086/300546](https://doi.org/10.1086%2F300546). [S2CID](/source/S2CID_(identifier)) [15908226](https://api.semanticscholar.org/CorpusID:15908226).

1. **[^](#cite_ref-8)** Shan, Huanyuan; Qin, Bo; Fort, Bernard; Tao, Charling; Wu, Xiang-Ping; Zhao, Hongsheng (2010). ["Offset between dark matter and ordinary matter: evidence from a sample of 38 lensing clusters of galaxies"](https://doi.org/10.1111%2Fj.1365-2966.2010.16739.x). *Monthly Notices of the Royal Astronomical Society*. **406** (2): 1134–1139. [arXiv](/source/ArXiv_(identifier)):[1004.1475](https://arxiv.org/abs/1004.1475). [Bibcode](/source/Bibcode_(identifier)):[2010MNRAS.406.1134S](https://ui.adsabs.harvard.edu/abs/2010MNRAS.406.1134S). [doi](/source/Doi_(identifier)):[10.1111/j.1365-2966.2010.16739.x](https://doi.org/10.1111%2Fj.1365-2966.2010.16739.x). [S2CID](/source/S2CID_(identifier)) [119255830](https://api.semanticscholar.org/CorpusID:119255830).

1. **[^](#cite_ref-9)** Lorenz, Suzanne; Peterson, J. R. (2013). "New Techniques in Dark Matter Mapping". *American Astronomical Society*. **222** (id.103.02): 103.02. [Bibcode](/source/Bibcode_(identifier)):[2013AAS...22210302L](https://ui.adsabs.harvard.edu/abs/2013AAS...22210302L).

## External links

Wikimedia Commons has media related to [Abell 2218](https://commons.wikimedia.org/wiki/Category:Abell_2218).

- [Release about Abell 2218 at ESA/Hubble](http://www.spacetelescope.org/news/html/heic0113.html)

- [Astronomy Picture of the Day](/source/Astronomy_Picture_of_the_Day) - [Abell 2218: A Galaxy Cluster Lens](https://apod.nasa.gov/apod/ap100620.html) - 2010 June 20

v t e Astronomical catalogs Abell Abell 2213 Abell 2214 Abell 2215 Abell 2216 Abell 2217 Abell 2218 Abell 2219 Abell 2220 Abell 2221 Abell 2222 Abell 2223

v t e Constellation of Draco List of stars in Draco Draco in Chinese astronomy Stars Bayer α (Thuban) β (Rastaban) γ (Eltanin) δ (Altais) ε (Tyl) ζ (Aldhibah) η (Athebyne) θ ι (Edasich) κ λ (Giausar) μ (Alrakis) ν (Kuma) ξ (Grumium) ο π ρ σ (Alsafi) τ υ φ χ ψ1 (Dziban) ψ2 ω Flamsteed 4 6 7 (Tianyi) 8 (Taiyi) 10 (i) 15 (A) 18 (g) 19 (h) 26 36 39 (b) 42 (Fafnir) 45 (d) 50 59 64 (e) 68 Variable TW YY AG BY CL CM CX DO EK HP V581 HR 3751 4126 4934 5811 6237 6518 6618 (Alruba) 6817 7137 7783 HD 109246 (Funi) 101364 128717 147379 156279 158259 176693 191939 Other 2MASS 1237+6526 2MASS J17554042+6551277 G 240-72 GD 356 Gliese 420 Gliese 625 Gliese 687 GRW +70 8247 Kepler-4 Kepler-10 Kepler-12 Kepler-90 Kepler-296 KOI-256 LP 71-82 Qatar-1 SDSS J1240+6710 Struve 2398 TOI-1136 WD 1856+534 WISE 1647+5632 WISE 1841+7000 Exoplanets HD 139357 b HD 167042 b ι Dra b (Hypatia) Kepler-4b Kepler-10b c Kepler-12b Kepler-90e f g h i Kepler-296b c d e f TOI-1452 b TrES-2b Star clusters LAMOST 1 Nebulae Cat's Eye Nebula NGC 6742 Galaxies NGC 3147 3197 3735 4121 4125 4221 4236 4319 4331 4332 4363 4441 4513 4545 4589 5678 5777 5866 5866B 5879 5905 5907 5949 5963 5965 5982 5985 6090 6248 6285 6286 6338 6340 6365 6373 6394 6412 6503 6505 6566 6621 6622 6670 6676 6786 6789 Other 1ES 1927+654 1ES 1959+650 3C 249.1 3C 305 3C 319 3C 343 3C 343.1 3C 351 3C 356 3C 371 3C 380 3C 390.3 3C 401 4C +72.26 4C 73.08 8C 1241+735 Abell 2218 BCG Bean galaxy Beaver galaxy BZQ J1727+5510 Draco Dwarf Draco II GB 1508+5714 Goldfish galaxy H1821+643 HFLS3 IERS B1946+708 IRAS F17179+5444 IRAS 18580+6527 J120011.1+680924.8 KKR 25 Markarian 817 Markarian 876 Original TRG PGC 39058 Porphyrion QSO B1823+568 RGZ J172749.5+534647 S5 1803+784 S5 2007+777 SDSS J1715+6008 Tadpole Galaxy UGC 9391 UGC 9405 UGC 11241 UGC 11411 WISEA J145223.62+611707.5 WN B1851+5707 Galaxy clusters Abell 2218 CL1358+62 Draco Supercluster NGC 5866 Group Astronomical events SN 2003jb SN 2005B SN 2016aps Swift J1644+57 Category

v t e Galaxies Morphology Disc Thick disk Thin disk Lenticular barred unbarred Spiral anemic barred flocculent grand design intermediate Magellanic unbarred Dwarf galaxy elliptical irregular spheroidal spiral Elliptical galaxy cD Irregular barred Peculiar Ring Polar Structure Active galactic nucleus Bar Bulge Central massive object Galactic Center Dark matter halo Disc Disc galaxy Halo corona Galactic plane Galactic ridge Interstellar medium Protogalaxy Galaxy filament Spiral arm Supermassive black hole Ultramassive Active nuclei Blazar BL Lacertae object LINER Little red dot Markarian Quasar Radio X-shaped DRAGN Relativistic jet Seyfert Energetic galaxies Lyman-alpha emitter Lyman-break Luminous infrared ULIRG HLIRG ELIRG Starburst blue compact dwarf blueberry pea faint blue Luminous infrared galaxy Hot dust-obscured Green bean galaxy Hanny's Voorwerp Wolf-Rayet galaxy Low activity Low surface brightness Ultra diffuse Dark galaxy Red nugget Blue Nugget Dead disk Interaction Binary galaxy Field Galactic tide Groups and clusters group cluster Brightest cluster galaxy fossil group Interacting merger collision cannibalism Jellyfish Satellite Stellar stream Superclusters Walls Voids and supervoids void galaxy Lists Galaxies Galaxies named after people Largest Smallest Nearest Polar-ring Ring Spiral Groups and clusters Large quasar groups Quasars List of the most distant astronomical objects Starburst galaxies Superclusters Voids Related Extragalactic astronomy Galactic astronomy Galactic coordinate system Galactic habitable zone Galactic magnetic fields Galactic orientation Galactic quadrant Galaxy color–magnitude diagram Galaxy formation and evolution Galaxy rotation curve Gravitational lens Gravitational microlensing Illustris project Intergalactic dust Intergalactic stars Intergalactic travel Population III stars Galaxy X (galaxy) Category Portal

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Adapted from the Wikipedia article [Abell 2218](https://en.wikipedia.org/wiki/Abell_2218) by Wikipedia contributors ([contributor history](https://en.wikipedia.org/wiki/Abell_2218?action=history)). Available under [Creative Commons Attribution-ShareAlike 4.0 International](https://creativecommons.org/licenses/by-sa/4.0/). Changes may have been made.