NGC 3656 | |
---|---|
Observation data (J2000 epoch) | |
Constellation | Ursa Major |
Right ascension | 11h 23m 38.7s [1] |
Declination | +53° 50′ 32″ [1] |
Redshift | 0.009640 ± 0.000037 [1] |
Helio radial velocity | 2,890 ± 11 km/s [1] |
Distance | 139 Mly (42.6 Mpc) [1] |
Apparent magnitude (V) | 12.3 [2] |
Characteristics | |
Type | (R')I0: pec [1] |
Apparent size (V) | 1.6′ × 1.6′ [1] |
Notable features | Merger remnant |
Other designations | |
UGC 6403, Arp 155, VV 22a, CGCG 268-029, MCG +09-19-063, PGC 34989 [1] |
NGC 3656 is a peculiar galaxy formed by the collision of two galaxies in the constellation of Ursa Major. It is located about 135 million light years away from Earth, which means, given its apparent dimensions, that NGC 3656 is approximately 70,000 light years across. It was discovered by William Herschel on April 14, 1789. [3]
NGC 3656 is a galaxy merger, created by the collision of two disk galaxies. The merger has created shells around the galaxy and two faint tidal tails. [4] The first tail emanates from a position angle of 260° and after bends to the north-northwest. Its total extent is about 180 arcseconds, towards a dwarf galaxy, and maybe even more, towards a second dwarf galaxy. Its width is 15 arcseconds. The other tail lies at the north-northeast part of the galaxy and is not as well defined as the other. [4] Other characteristics of the galaxy include the presence of a condensation at the south part of the galaxy connected with the rest of the galaxy with a ring-like feature and is associated with a bright shell. [4] [5]
A prominent feature of the galaxy is a dark lane running across the minor axis of the galaxy, similar to that observed in Centaurus A. [5] At the centre of the galaxy a warped molecular gas disk extending for about 7 kiloparsecs has been observed in H I imaging, with an estimated mass of 2×109M☉. [6] The inner part of the disk features more intense star formation. [7] The total star formation rate of the galaxy is estimated to be 1.1 M☉ per year. [8]
The nucleus of NGC 3656 has been found to rotate around an axis that is almost perpendicular to the rotation axis of the rest of the galaxy, which is another indication of a galaxy merger. [9]
Two supernovae have been observed in the galaxy, SN 1963K, with a peak apparent magnitude of 15, and SN 1973C, with a peak apparent magnitude of 17. Both supernovae were not specified as far as their type was concerned. [10]
NGC 3656 is the foremost member in a galaxy group known as the NGC 3656 group. Another member is UGC 6422. A bit further away lies the galaxy NGC 3549 with its group. [11] Five dwarf galaxies with estimated masses between 2×108 and 2×109M☉ have been detected in HI imaging around the galaxy and are probably in the process of being accreted by NGC 3656. [6]
NGC 520 is a pair of colliding spiral galaxies about 105 million light-years away in the constellation Pisces. They were discovered by astronomer William Herschel on 13 December 1784.
NGC 4651 is a spiral galaxy located in the constellation of Coma Berenices that can be seen with amateur telescopes, at a distance not well determined that ranges from 35 million light years to 72 million light years.
NGC 1084 is an unbarred spiral galaxy in the constellation Eridanus. It is located at a distance of about 63 million light-years away from the Milky Way. The galaxy was discovered by William Herschel on 10 January 1785. It has multiple spiral arms, which are not well defined. It belongs in the same galaxy group with NGC 988, NGC 991, NGC 1022, NGC 1035, NGC 1042, NGC 1047, NGC 1052 and NGC 1110. This group is in turn associated with the Messier 77 group.
NGC 2655 is a lenticular galaxy in the constellation Camelopardalis. It is at a distance of 60 million light years from Earth. NGC 2655 is a Seyfert galaxy. The galaxy has asymmetric dust lanes in the centre of the galaxy, tidal arms and extended neutral hydrogen gas and may have recently experienced a merger. The complex dynamics of the HI and optical tails suggest the galaxy may have undergone more mergers in the past. A weak bar has been detected in infrared H band. The diameter of the disk of the galaxy is estimated to be 60 Kpc.
NGC 1003 is a spiral galaxy at the western edge of the Perseus constellation. It is located at a distance of about 36 million light years from the Milky Way and is receding with a heliocentric radial velocity of 624 km/s. This galaxy was discovered by the Anglo-German astronomer William Herschel on October 6, 1784, who described it as "pretty faint, large, extended 90°±, much brighter middle, mottled but not resolved". It is a member of the NGC 1023 group of galaxies.
NGC 4699 is an intermediate spiral galaxy located in the constellation Virgo. It is located at a distance of circa 65 million light years from Earth, which, given its apparent dimensions, means that NGC 4699 is about 85,000 light years across. It was discovered by William Herschel in 1786. It is a member of the NGC 4699 Group of galaxies, which is a member of the Virgo II Groups, a series of galaxies and galaxy clusters strung out from the southern edge of the Virgo Supercluster.
NGC 720 is an elliptical galaxy located in the constellation Cetus. It is located at a distance of circa 80 million light years from Earth, which, given its apparent dimensions, means that NGC 720 is about 110,000 light years across. It was discovered by William Herschel on October 3, 1785. The galaxy is included in the Herschel 400 Catalogue. It lies about three and a half degrees south and slightly east from zeta Ceti.
NGC 7469 is an intermediate spiral galaxy in the constellation of Pegasus. NGC 7469 is located about 200 million light-years away from Earth, which means, given its apparent dimensions, that NGC 7469 is approximately 90,000 light-years across. It was discovered by William Herschel on November 12, 1784.
NGC 3367 is a barred spiral galaxy located in the constellation Leo. It is located at a distance of about 120 million light years from Earth, which, given its apparent dimensions, means that NGC 3367 is about 85,000 light years across. It was discovered by William Herschel on March 19, 1784.
NGC 541 is a lenticular galaxy located in the constellation Cetus. It is located at a distance of circa 230 million light years from Earth, which, given its apparent dimensions, means that NGC 541 is about 130,000 light years across. It was discovered by Heinrich d'Arrest on October 30, 1864. It is a member of the Abell 194 galaxy cluster and is included in the Atlas of Peculiar Galaxies in the category galaxies with nearby fragments. NGC 541 is a radio galaxy of Fanaroff-Riley class I, also known as 3C 40A.
NGC 5965 is a spiral galaxy located in the constellation Draco. It is located at a distance of circa 150 million light years from Earth, which, given its apparent dimensions, means that NGC 5965 is about 260,000 light years across. It was discovered by William Herschel on May 5, 1788.
NGC 7130 is a spiral galaxy located in the constellation Piscis Austrinus. It is located at a distance of about 220 million light years from Earth, which, given its apparent dimensions, means that NGC 7130 is about 100,000 light years across. It was discovered by John Herschel on September 25, 1834, and discovered independently by Lewis Swift on September 17, 1897. The location of the galaxy given in the New General Catalogue was off by 30 arcminutes in declination from the location of the galaxy.
NGC 5982 is an elliptical galaxy located in the constellation Draco. It is located at a distance of circa 130 million light years from Earth, which, given its apparent dimensions, means that NGC 5982 is about 100,000 light years across. It was discovered by William Herschel on May 25, 1788.
NGC 7674 is a spiral galaxy located in the constellation Pegasus. It is located at a distance of circa 350 million light years from Earth, which, given its apparent dimensions, means that NGC 7674 is about 125,000 light years across. It was discovered by John Herschel on August 16, 1830.
NGC 6907 is a spiral galaxy located in the constellation Capricornus. It is located at a distance of about 120 million light years from Earth, which, given its apparent dimensions, means that NGC 6907 is about 115,000 light years across. It was discovered by William Herschel on July 12, 1784. The total infrared luminosity of the galaxy is 1011.03 L☉, and thus it is categorised as a luminous infrared galaxy.
NGC 7531 is an intermediate spiral galaxy located in the constellation Grus. It is located at a distance of circa 70 million light-years from Earth, which, given its apparent dimensions, means that NGC 7531 is about 95,000 light years across. It was discovered by John Herschel on September 2, 1836.
NGC 5363 is a lenticular galaxy located in the constellation Virgo. It is located at a distance of circa 65 million light years from Earth, which, given its apparent dimensions, means that NGC 5363 is about 100,000 light years across. It was discovered by William Herschel on January 19, 1784. It is a member of the NGC 5364 Group of galaxies, itself one of the Virgo III Groups strung out to the east of the Virgo Supercluster of galaxies.
NGC 2273 is a barred spiral galaxy located in the constellation Lynx. It is located at a distance of circa 95 million light years from Earth, which, given its apparent dimensions, means that NGC 2273 is about 100,000 light years across. It was discovered by Nils Dunér on September 15, 1867.
NGC 1142 is a distorted spiral galaxy in the constellation of Cetus. It is located about 370 million light years away from Earth, which means, given its apparent dimensions, that NGC 1142 is approximately 170,000 light years across. It is a type 2 Seyfert galaxy. It interacts with the elliptical galaxy NGC 1141.
NGC 7592 is an interacting galaxy system located 300 million light years away in the constellation Aquarius. It was discovered by William Herschel on September 20, 1784. The total infrared luminosity is 1011.33 L☉, and thus it is categorised as a luminous infrared galaxy. One of the galaxies hosts a type 2 Seyfert nucleus.