NGC 3640 is an
elliptical galaxy located in the constellation
Leo
Leo or Léo may refer to:
Acronyms
* Law enforcement officer
* Law enforcement organisation
* ''Louisville Eccentric Observer'', a free weekly newspaper in Louisville, Kentucky
* Michigan Department of Labor and Economic Opportunity
Arts an ...
. It is located at a distance of circa 75 million
light year
A light-year, alternatively spelled light year, is a large unit of length used to express astronomical distances and is equivalent to about 9.46 trillion kilometers (), or 5.88 trillion miles ().One trillion here is taken to be 1012 ...
s from Earth, which, given its apparent dimensions, means that NGC 3640 is about 90,000 light years across. It was discovered by
William Herschel on February 23, 1784.
It is a member of the
NGC 3640 Group
The Leo II Groups, or Leo II Cloud, are a series of at least 110 galactic clusters and individual galaxy, galaxies stretching approximately 30 Mly (9.2 Mpc) off the right edge of the Virgo Supercluster. It is located approximately 65 Mly (20 Mpc) ...
of galaxies, which is a member of the
Leo II Groups
The Leo II Groups, or Leo II Cloud, are a series of at least 110 galactic clusters and individual galaxies stretching approximately 30 Mly (9.2 Mpc) off the right edge of the Virgo Supercluster. It is located approximately 65 Mly (20 Mpc) to 95 M ...
, a series of galaxies and
galaxy clusters strung out from the right edge of the
Virgo Supercluster.
It lies 2 degrees south of
Sigma Leonis and is a member of the
Herschel 400 Catalogue. It is condensed and can be spotted with a small telescope from suburban skies.
Characteristics
NGC 3640 is an elliptical galaxy with a highly disturbed stellar component. The galaxy features boxy isophotes, and patchy
shell-like features. These features indicate a recent
merger
Mergers and acquisitions (M&A) are business transactions in which the ownership of companies, other business organizations, or their operating units are transferred to or consolidated with another company or business organization. As an aspect ...
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. The HI mass of the galaxy is estimated to be and the mass of HII less than .
In the centre of NGC 3640 lies a
supermassive black hole whose mass is estimated to be roughly 100 million (10
7.99 ± 0.39) based on the Sérsic profile.
Nearby galaxies
NGC 3640 is the foremost galaxy in a
galaxy group known as the NGC 3640 group. Other members of the group include
NGC 3630,
NGC 3641,
NGC 3643, and
NGC 3664
NGC 3664 is a magellanic barred spiral galaxy in the constellation of Leo. It is located about 80 million light years away from Earth, which means, given its apparent dimensions, that NGC 3664 is approximately 50,000 light years across. It was d ...
.
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 the
Virgo supercluster scattered across 30 million light years of space west of the
Virgo cluster.
See also
*
NGC 2865 and
NGC 5018 - two other elliptical galaxies with disturbed morphology
References
External links
*
NGC 3640 on SIMBAD
{{Ngc40
Elliptical galaxies
Shell galaxies
Leo (constellation)
3640
06368
34778
Astronomical objects discovered in 1784
Discoveries by William Herschel