| NGC 3640 | |
|---|---|
.jpg) VLT Survey Telescope image of NGC 3640 andNGC 3641 (bottom) | |
| Observation data (J2000epoch) | |
| Constellation | Leo |
| Right ascension | 11h 21m 06.8s[1] |
| Declination | +03° 14′ 05″[1] |
| Redshift | 0.004330 ± 0.000017[1] |
| Heliocentric radial velocity | 1,298 ± 5km/s[1] |
| Distance | 75.4 ± 25Mly (23.1 ± 7.7Mpc)[1] |
| Apparent magnitude (V) | 10.3[2] |
| Characteristics | |
| Type | E3[1] |
| Apparent size (V) | 4.0′ × 3.2′[1] |
| Other designations | |
| UGC 6368, CGCG 039-130,MCG +01-29-033,PGC 34778[1] | |
NGC 3640 is anelliptical galaxy located in the constellationLeo. It is located at a distance of circa 75 millionlight years from Earth, which, given its apparent dimensions, means that NGC 3640 is about 90,000 light years across. It was discovered byWilliam Herschel on February 23, 1784.[3] It is a member of theNGC 3640 Group of galaxies, which is a member of theLeo II Groups, a series of galaxies andgalaxy clusters strung out from the right edge of theVirgo Supercluster.[4]
It lies 2 degrees south ofSigma Leonis and is a member of theHerschel 400 Catalogue. It is condensed and can be spotted with a small telescope from suburban skies.[5]
NGC 3640 is an elliptical galaxy with a highly disturbed stellar component.[6] The galaxy features boxy isophotes, and patchyshell-like features. These features indicate a recentmerger with a smaller gas-poor galaxy. A dust lane is observed along the minor-axis, spanning 30 arcseconds in a north-south direction. The galaxy has a high rotational velocity, estimated to be 120 ± 10 km/s, higher than that of other elliptical galaxies of similar luminosity.[7] The HI mass of the galaxy is estimated to be1.85×107 M☉ and the mass of HII less than7.44×107 M☉.[8]
In the centre of NGC 3640 lies asupermassive black hole whose mass is estimated to be roughly 100 million (107.99 ± 0.39)M☉ based on the Sérsic profile.[9]
NGC 3640 is the foremost galaxy in agalaxy group known as the NGC 3640 group. Other members of the group includeNGC 3630,NGC 3641,NGC 3643, andNGC 3664.[10] NGC 3640 forms a pair with NGC 3641, which lies 2.5 arcminutes south from NGC 3640. The group belongs to the Leo II groups, a large collection of galaxies belonging to theVirgo Supercluster scattered across 30 million light years of space west of theVirgo Cluster.[11]
Media related toNGC 3640 at Wikimedia Commons