Astronomy:Abell 222
| Abell 222 | |
|---|---|
| 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 (co-moving) | 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]
Discovery of dark matter
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]
Baryonic matter evidence
About 5% of the universe is estimated to be made up of baryonic or ordinary matter which contains protons and neutrons, also known as baryons, and electrons. Baryons and electrons are the foundation for atoms. Astronomers have not been able to locate the full 5% of baryonic matter within other galaxies, stars or gases. After observing gas that connects Abell 222 and Abell 223, scientists believe that a significant part of the missing baryonic matter is within the gas that bridges the two galaxy clusters. This was difficult to locate due to the fact that the gas had a very low density, which made it hard to detect. This discovery was made possible because of Abell 222's location. It is within Earth's line of sight, so scientists were able to see a strong concentration of this extremely distant gas with the latest high-power infrared and X-ray telescopes, within a section of the sky.[11]
See also
References
- ↑ 1.0 1.1 1.2 "ACO 222". SIMBAD. Centre de données astronomiques de Strasbourg. http://simbad.u-strasbg.fr/simbad/sim-basic?Ident=ACO+222.
- ↑ "2MASX J01373406-1259288". SIMBAD. Centre de données astronomiques de Strasbourg. http://simbad.u-strasbg.fr/simbad/sim-basic?Ident=2MASX+J01373406-1259288.
- ↑ 3.0 3.1 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. doi:10.1086/191333. ISSN 0067-0049. Bibcode: 1989ApJS...70....1A.
- ↑ 4.0 4.1 Durret, F; Laganá, T. F; Adami, C; Bertin, E (2010). "The clusters Abell 222 and Abell 223: A multi-wavelength view". Astronomy and Astrophysics 517: A94. doi:10.1051/0004-6361/201014566. Bibcode: 2010A&A...517A..94D.
- ↑ "NED results for object ABELL 0222". National Aeronautics and Space Administration / Infrared Processing and Analysis Center. http://nedwww.ipac.caltech.edu/cgi-bin/nph-objsearch?objname=Abell+222&extend=no&out_csys=Equatorial&out_equinox=J2000.0&obj_sort=RA+or+Longitude&of=pre_text&zv_breaker=30000.0&list_limit=5&img_stamp=YES.
- ↑ 6.0 6.1 Pete Spotts (5 July 2012). "Cosmic scaffolding uncovered? Scientists find thread of dark matter.". The Christian Science Monitor. Christian Science Publishing Society. http://www.csmonitor.com/Science/2012/0705/Cosmic-scaffolding-uncovered-Scientists-find-thread-of-dark-matter.
- ↑ "Dark Matter Filaments Detected in Abell 222 And Abel 223 Supercluster" (in en). 2014-08-27. http://www.science20.com/news_articles/dark_matter_filaments_detected_abell_222_and_abel_223_supercluster-91809.
- ↑ "ID: SEMHZOZXUFF: Galaxy clusters Abell 222 and Abell 223". esa. http://www.esa.int/esa-mmg/mmg.pl?idf=SEMHZOZXUFF&type=I.
- ↑ "Eine Brücke aus dunkler Materie zwischen zwei Galaxienhaufen" (in de). Neue Zürcher Zeitung. 17 July 2012. http://www.nzz.ch/.
- ↑ Dietrich, Jörg. "The Abell 222/223 Supercluster with dark matter Filament". University of Michigan/University Observatory Munich. https://www.usm.lmu.de/people/dietrich/gallery/a222_dm_labeled.html.
- ↑ "Do Abell 222 And Abell 223 Contain The Universe's 'Missing' Baryonic Matter?" (in en). 2014-08-27. http://www.science20.com/news_releases/do_abell_222_and_abell_223_contain_the_universes_missing_baryonic_matter.
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