Eridanus Cluster

Not to be confused with Eridanus Group.
Eridanus Cluster
Observation data (Epoch J2000)
Constellation(s)Eridanus
Right ascension03h 28m 13.8s[1]
Declination−20° 44′ 40″[1]
Brightest memberNGC 1232 (B)
Number of galaxies~200[2]
Velocity dispersion261 km/s[3]
Redshift0.005570[1]
Distance23 Mpc (75 Mly)[1]
ICM temperature~107 K (~1 keV)[2]
Binding mass~1014[3] M☉
X-ray flux0.105 mCrab[2]
Other designations
Fornax II Cluster,[4] de Vaucouleurs Group 31[5]
The spiral galaxy NGC 1232 is one of the brightest in the Eridanus Cluster.
The barred spiral galaxy NGC 1300 is a well-known member of the Eridanus Cluster.

The Eridanus Cluster is a galaxy cluster roughly 23 Mpc (75 Mly) from Earth, containing about 73 main galaxies and about 200 total galaxies. About 30% have Hubble classifications of elliptical or S0 and the remaining 70% are spiral or irregular.[2] These galaxies reside in smaller groups which are all loosely gravitationally bound to each other, suggesting that the system is still condensing from the Hubble flow and may eventually form a cluster of about 1014 M☉. A low velocity dispersion compared to that of, for example, the Coma cluster, supports this hypothesis.[3] The Eridanus Cluster is located in the constellation Eridanus near the Fornax Cluster, and is sometimes called the "Fornax II Cluster".[4]

  1. ^ a b c d "Eridanus Cluster". NASA/IPAC Extragalactic Database (NED). Retrieved 2012-02-25.
  2. ^ a b c d Omar, A.; Dwarakanath, K. S. (March 2005). "GMRT HI Observations of the Eridanus Group of Galaxies I" (PDF). Journal of Astrophysics and Astronomy. 26 (1): 1–33. arXiv:astro-ph/0503536. Bibcode:2005JApA...26....1O. doi:10.1007/BF02702451. S2CID 7451092. Retrieved 2012-02-25.
  3. ^ a b c Willmer, C. N. A.; Rocardi, P.; da Costa, L. Nicolaci; Pellegrini, P. S. (November 1989). "Studies of nearby poor clusters – The Eridanus group" (PDF). Astronomical Journal. 98 (Nov. 1989): 1531–1541. Bibcode:1989AJ.....98.1531W. doi:10.1086/115236. ISSN 0004-6256. Retrieved 2012-02-25.
  4. ^ a b atlasoftheuniverse.com
  5. ^ Chincarini, G.; Rood, H. J.; Welch, G. A. (March 1975). "A re-analysis of the dynamics of the nearby groups of galaxies". Monthly Notices of the Royal Astronomical Society. 170 (Mar. 1975): 441–445. Bibcode:1975MNRAS.170..441C. doi:10.1093/mnras/170.3.441. A&AA ID. AAA013.160.006.