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]
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

  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.
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