Fornax Cluster
# Fornax Cluster

The Fornax Cluster is a cluster of galaxies lying at a distance of 19 megaparsecs (62 million light-years). It has an estimated mass of $(7±2)×10^{13}$ solar masses, making it the second richest galaxy cluster within 100 million light-years, after the considerably larger Virgo Cluster. It may be associated with the nearby Eridanus Group. It lies primarily in the constellation Fornax, with its southern boundaries partially crossing into the constellation of Eridanus, and covers an area of sky about 6° across or about 28 sq degrees.

The Fornax Cluster is a particularly valuable source of information about the evolution of such clusters due to its relatively close proximity to the Sun. It also shows the gravitational effects of a merger of a galaxy subgroup with the main galaxy group, which in turn lends clues about the associated galactic superstructure. At the centre of the cluster lies NGC 1399. Other cluster members include NGC 1316 (the group's brightest galaxy), NGC 1365, NGC 1427A, NGC 1427 and NGC 1404.

## Structure

Fornax can be divided into two subclusters: the main cluster, centered on NGC 1399, and a subgroup 3 degrees to the southwest centered on the lenticular galaxy NGC 1316 that is currently in the process of infalling with the largest subcluster to merge with it, and whose galaxies are experiencing relatively strong star formation activity.

## Intracluster medium

As with many other galaxy clusters, Fornax intracluster medium is filled with a hot, rarefied gas that emits X-rays. and contains a number of intergalactic stars, some of which have produced novae.

## List of cluster members

Cluster Members :

| Designation | Coordinates (Epoch 2000) | Coordinates (Epoch 2000) | Apparent magnitude | Type | Mean Angular diameter (arcminutes) | Diameter (x1000 Light-years) | Distance (mly) | Recessional velocity (km/s) |
| - | - | - | - | - | - | - | - | - |
| Designation | Right Ascension | Declination | Apparent magnitude | Type | Mean Angular diameter (arcminutes) | Diameter (x1000 Light-years) | Distance (mly) | Recessional velocity (km/s) |
| NGC 4627 | 03 37.7 | −32 29 | 13.1 | E4 pec | 1.5′ | 375 | 71 | 1451 |
| ESO 357-07 | 03 10.4 | −33 09 | 14.7 | SBm | 2.2′ | 40 | | 981 |
| ESO 357-12 | 03 16.9 | −35 32 | 14.8 | SBcd | 2.2′ | 40 | | 1445 |
| IC 1913 | 03 19.6 | −32 28 | 14.5 | SBb | 2.1′ | 40 | 67 | 1318 |
| NGC 1310 | 03 21.1 | −37 06 | 13 | SBc | 1.9′ | 35 | 64 | 1640 |
| LEDA 12625 | 03 22.1 | −37 35 | ? | Irr | 2.9′ | 55 | | 1507 |
| NGC 1316 | 03 22.7 | −37 12 | 9.4 | (R')SAB(s)0 | 11.5′ | 215 | 62 | 1664 |
| NGC 1317 | 03 22.7 | −37 06 | 11.9 | SBa | 3.0′ | 55 | 70 | 1935 |
| NGC 1326 | 03 23.9 | −36 28 | 11.5 | S0 | 4.3′ | 80 | 63 | 1247 |
| NGC 1326A | 03 25.1 | −36 22 | 14.7 | SBm | 1.7′ | 30 | 84 | 1719 |
| NGC 1326B | 03 25.3 | −36 23 | 13.7 | SBm | 3.5′ | 65 | 46 | 888 |
| IC 1919 | 03 26.0 | −32 54 | 13.9 | E | 1.6′ | 30 | 61 | 1158 |
| NGC 1336 | 03 26.5 | −35 43 | 13.4 | E | 1.9′ | 35 | 65 | 1360 |
| NGC 1341 | 03 28.0 | −37 09 | 13.3 | SBab | 1.6′ | 30 | 86 | 1760 |
| NGC 1339 | 03 28.1 | −32 17 | 12.8 | E | 1.9′ | 35 | 64 | 1240 |
| NGC 1344 | 03 28.3 | −31 04 | 11.2 | E | 5.6′ | 105 | 60 | 1052 |
| ESO 358-09 | 03 28.8 | −35 11 | 14.2 | SBbc | 2.3′ | 45 | | 1241 |
| ESO 358-10 | 03 29.7 | −33 33 | 14.8 | E | 1.5′ | 30 | | 1620 |
| NGC 1351 | 03 30.6 | −34 51 | 12.4 | E-S0 | 3.2′ | 60 | 69 | 1420 |
| NGC 1350* | 03 31.1 | −33 38 | 11.2 | Sa(r) | 5.8′ | 130 | 87 | 1905 |
| NGC 1365 | 03 33.6 | −36 08 | 10.3 | (R')SBb(s)b | 11.0′ | 205 | 56 | 1636 |
| NGC 1366 | 03 33.9 | −31 12 | 13.1 | S0 | 1.9′ | 35 | 56 | 1137 |
| NGC 1374 | 03 35.3 | −35 14 | 11.0 | E | 2.7′ | 50 | 59 | 1240 |
| NGC 1375* | 03 35.3 | −35 16 | 12.2 | SB0 pec | 2.1′ | 23 | 28 | 643 |
| IC 335 | 03 35.5 | −34 27 | 13.4 | S0 | 2.3′ | 45 | 60 | 1530 |
| NGC 1379 | 03 36.1 | −35 26 | 11.9 | E | 2.6′ | 50 | 60 | 1264 |
| NGC 1380 | 03 36.5 | −34 59 | 9.9 | S0 | 4.8′ | 85 | 60 | 1737 |
| NGC 1381 | 03 36.5 | −35 18 | 11.5 | S0 | 2.6′ | 55 | 60 | 1673 |
| NGC 1369 | 03 36.8 | −36 15 | 13.6 | Sa | 1.7′ | 30 | 65 | 1340 |
| NGC 1386 | 03 36.8 | −36 00 | 11.2 | (R′)SA(r)0/a | 3.4′ | 65 | 53 | 868 |
| NGC 1380A | 03 36.8 | −34 44 | 13.4 | S0 | 2.5′ | 45 | 72 | 1419 |
| NGC 1387 | 03 37.0 | −35 30 | 10.8 | (R')SAB(s)0 | 3.2′ | 60 | 53 | 1296 |
| NGC 1382 | 03 37.1 | −35 12 | 13.8 | E | 1.5′ | 30 | 80 | 1697 |
| NGC 1389 | 03 37.2 | −35 45 | 12.6 | E | 2.6′ | 50 | 42 | 883 |
| NGC 1396 | 03 38.6 | −35 27 | 13.8 | E | 0.7′ | 7 | 67 | 853 |
| NGC 1399 | 03 38.5 | −35 26 | 9.9 | E | 6.8′ | 130 | 66 | 1335 |
| NGC 1404 | 03 38.9 | −35 36 | 10.9 | E | 4.1′ | 75 | 65 | 1942 |
| NGC 1406 | 03 39.4 | −31 19 | 12.9 | SBbc | 3.9′ | 75 | 50 | 963 |
| NGC 1427A | 03 40.1 | −35 38 | 13.4 | Irr | 2.1′ | 40 | 52 | 2028 |
| ESO 358-50 | 03 41.1 | −33 47 | 13.9 | S0 | 1.6′ | 30 | | 1151 |
| ESO 358-51 | 03 41.5 | −34 53 | 14.1 | Sa | 1.5′ | 30 | | 1626 |
| NGC 1425 | 03 42.2 | −29 54 | 11.4 | SA(rs)b | 6.0′ | 115 | 69 | 1402 |
| NGC 1427 | 03 42.3 | −35 24 | 11.8 | E | 3.6′ | 70 | 71 | 1327 |
| NGC 1428 | 03 42.4 | −35 09 | 14.0 | E | 1.5′ | 30 | 75 | 1602 |
| NGC 1437A | 03 43.0 | −36 16 | 14.2 | SBd | 1.7′ | 30 | 41 | 798 |
| NGC 1436 | 03 43.6 | −35 51 | 11.7 | SBab | 2.8′ | 50 | 58 | 1296 |
| ESO 358-60 | 03 45.2 | −35 34 | 15.6 | Irr | 1.7′ | 30 | | 710 |
| NGC 1437B | 03 45.9 | −36 22 | 14.0 | Sc | 2.5′ | 45 | 69 | 1415 |
| NGC 1460 | 03 46.2 | −36 42 | 13.5 | SB0 | 1.7′ | 30 | 63 | 1341 |
| PGC 13809 | 03 46.3 | −34 57 | 12.6 | Sc | 4.8′ | 90 | | 1838 |
| IC 1993 | 03 47.1 | −33 42 | 12.6 | (R')SA(s)bc | 2.5′ | 45 | 50 | 1057 |
| ESO 302-09 | 03 47.6 | −38 35 | 14.6 | SBd | 2.2′ | 40 | | 908 |
| ESO 302-14 | 03 51.7 | −38 27 | 15.5 | Irr | 1.5′ | 30 | | 798 |
| ESO 359-03 | 03 52.0 | −33 28 | 14.1 | Sab | 1.8′ | 35 | | 1495 |
| NGC 1484 | 03 54.3 | −36 58 | 13.9 | Sb | 2.5′ | 45 | 48 | 952 |
| IC 2006 | 03 54.3 | −35 58 | 12.5 | E | 1.9′ | 35 | 65 | 1382 |
| NGC 1531 | 04 11.2 | −32 51 | 12.9 | S0 | 1.3′ | 15 | 57 | 1169 |
| NGC 1532 | 04 12.1 | −32 52 | 10.7 | SBb | 12.6′ | 210 | 57 | |

(*) - Membership is uncertain

## Gallery

* NGC 1399 galaxy by the HST; 2.76′ view.
