Galaxy cluster in the constellation Eridanus
Eridanus Cluster Observation data (Epoch J2000) Constellation(s) Eridanus Right ascension 03h 28m 13.8s [1] Declination −20° 44′ 40″[1] Brightest member NGC 1232 (B) Number of galaxies ~200[2] Velocity dispersion 261 km/s[3] Redshift 0.005570[1] Distance 23 Mpc (75 Mly)[1] ICM temperature ~107 K (~1 keV)[2] Binding mass ~1014 [3] M ☉ X-ray flux 0.105 mCrab[2] Other designations Fornax II Cluster,[4] de Vaucouleurs Group 31[5] See also: Galaxy group, Galaxy cluster, List of galaxy groups and clusters
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]
Table of galaxies Name of the galaxy Right ascension for epoch J2000 Declination for epoch J2000 Blue apparent magnitude of the galaxy Galaxy type : E=Elliptical; S0=Lenticular; Sa, Sb, Sc, Sd=Spiral (degree of woundedness of spiral arms); SBa, SBb, SBc, SBd=Barred Spiral; SAB= Intermediate Spiral (between barred and unbarred); Sm, SBm, Irr=Irregular; (r),(rs)=Ring Structure Angular diameter of the galaxy (arcminutes ) Diameter of the galaxy (thousands of light years) Recessional velocity (km/s) of the galaxy relative to the cosmic microwave background Name RA equatorial coordinates Dec equatorial coordinates Blue Mag Type Size (arcmin) Size (kly) RV (km/s) ESO 547-09 03 06.0 –19 23 16.8 Irr 1.3 35 1509 ESO 547-12 03 09.6 –17 50 16.5 Scd 1.5 35 1837 NGC 1232 03 09.8 –20 35 10.7 SAB(rs)c 6.9 170 1517 IC 1898 03 10.3 –22 24 13.7 SBc 3.4 85 1164 ESO 547-20 03 13.0 –17 56 16.0 SBm 1.2 30 1825 NGC 1258 03 14.1 –21 46 13.9 SBc 1.3 30 1340 NGC 1297 03 19.2 –19 06 13.5 E 2.0 50 1395 NGC 1300 03 19.7 –19 25 11.2 SBbc 6.0 110 1421 NGC 1315 03 23.1 –21 23 14.0 S0 1.5 35 1534 PGC 12680 03 23.4 –19 17 ? Irr 1.3 30 1400 ESO 548-05 03 23.8 –19 45 14.7 SBm 1.5 35 1690 NGC 1325 03 24.4 –21 33 12.3 SBbc 4.7 115 1446 NGC 1325A 03 24.8 –21 20 13.6 SBcd 1.8 45 1188 ESO 548-16 03 26.0 –21 20 15.6 Scd 1.7 40 1977 NGC 1332 03 26.3 –21 20 11.4 E 4.2 105 1383 ESO 548-21 03 27.6 –21 14 14.7 SBd 2.0 50 1541 ESO 548-25 03 29.0 –22 09 15.0 SBa 1.3 30 1542 NGC 1345 03 29.5 –17 47 14.3 SBc 1.4 35 1385 ESO 481-30 03 29.6 –23 21 15.5 Scd 1.5 35 1504 NGC 1347 03 29.7 –22 17 13.9 SBc 1.4 35 1624 ESO 548-28 03 30.6 –17 56 14.0 S0 1.3 35 1360 ESO 548-29 03 30.8 –21 03 14.3 SBbc 1.1 30 1175 NGC 1353 03 32.1 –20 49 12.4 SBb 3.5 85 1390 ESO 548-32 03 32.3 –17 43 15.8 SBm 1.6 40 1815 ESO 548-33 03 32.5 –18 57 14.5 S0 1.3 35 1552 ESO 548-34 03 33.0 –21 05 14.6 SBc 1.1 30 1610 ESO 482-05 03 33.0 –24 08 15.2 SBcd 2.1 50 1783 NGC 1357 03 33.2 –13 39 12.4 Sab 3.2 85 2018 IC 1952 03 33.4 –23 43 13.5 SBbc 2.5 60 1683 IC 1953 03 33.7 –21 29 12.7 SBc 2.6 65 1733 NGC 1359 03 33.8 –19 29 13.0 SBm 2.1 55 1833 NGC 1362 03 33.9 –20 17 14.2 S0 1.2 30 1085 ESO 548-44 03 34.3 –19 25 14.2 S0 1.3 35 1561 ESO 548-47 03 34.7 –19 02 14.1 S0 2.5 60 1472 NGC 1367 03 35.0 –24 56 11.6 SBa 5.6 140 1344 NGC 1370 03 35.2 –20 22 13.9 E 1.5 35 933 IC 1962 03 35.6 –21 18 14.8 SBd 2.5 60 1670 ESO 482-11 03 36.3 –25 36 14.7 Sbc 1.4 35 1469 NGC 1377 03 36.7 –20 54 13.8 S0 1.7 45 1645 NGC 1385 03 37.5 –24 30 11.5 SBc 3.7 90 1373 NGC 1383 03 37.7 –18 20 13.8 S0 1.7 40 1828 ESO 482-17 03 37.7 –22 55 14.9 Sab 1.3 30 1330 NGC 1390 03 37.9 –19 00 14.9 SBa 1.3 35 1078 NGC 1395 03 38.5 –23 02 10.7 E 5.6 140 1577 NGC 1398 03 38.9 –26 20 10.5 SB(r)ab 7.1 135 1289 NGC 1403 03 39.2 –22 23 14.1 E 1.3 30 1751 NGC 1401 03 39.4 –22 43 13.7 S0 1.9 50 1406 NGC 1400 03 39.5 –18 41 12.3 E 2.3 60 415 ESO 548-63 03 39.6 –20 01 15.1 Sbc 1.4 35 1846 ESO 548-65 03 40.0 –19 22 15.3 Sa 1.4 35 1102 IC 343 03 40.1 –18 27 14.3 S0 1.4 35 1730 NGC 1407 03 40.2 –18 35 10.9 E 5.1 125 1650 ESO 548-68 03 40.3 –18 56 14.3 E 1.3 35 1636 NGC 1412 03 40.5 –26 52 14.7 S0 1.4 35 1675 ESO 548-70 03 40.7 –22 17 15.4 SBcd 1.6 40 1615 ESO 482-32 03 40.7 –26 47 15.9 Irr 1.2 30 1621 NGC 1415 03 40.9 –22 34 12.8 Sa 3.3 80 1451 NGC 1414 03 41.0 –21 43 14.6 SBbc 1.6 40 1464 ESO 482-35 03 41.2 –23 50 14.2 SBab 1.8 45 1756 NGC 1422 03 41.5 –21 41 14.2 SBab 2.3 55 1514 IC 346 03 41.7 –18 16 13.9 S0 1.9 45 1830 ESO 548-79 03 41.9 –18 54 14.8 Sa 1.1 30 1914 ESO 548-82 03 42.7 –17 30 15.4 Sbc 1.1 30 1590 NGC 1426 03 42.8 –22 06 12.7 E 2.5 60 1296 ESO 549-02 03 43.0 –19 01 14.9 SBm 1.3 30 988 ESO 549-06 03 43.6 –21 14 15.7 Irr 1.3 30 1490 NGC 1439 03 44.8 –21 55 12.4 E 2.6 65 1577 NGC 1440 03 45.0 –18 16 12.9 S0 2.2 55 1403 NGC 1438 03 45.3 –23 00 13.3 SBa 2.0 50 1438 NGC 1452 03 45.4 –18 38 12.9 Sa 2.3 60 1619 ESO 549-18 03 48.2 –21 28 13.3 SBc 2.5 60 1473 ESO 482-46 03 49.7 –27 00 13.7 Sc 3.5 90 1422 ESO 482-49 03 52.4 –23 03 15.3 Sc 1.1 30 1377 NGC 1482 03 54.6 –20 30 13.3 S0 2.2 55 1753
See also References ^ a b c d "Eridanus Cluster". NASA/IPAC Extragalactic Database (NED). Retrieved 2012-02-25 . ^ 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 . ^ 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 . ^ a b atlasoftheuniverse.com ^ 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.