NGC 3396 is a
peculiar barred irregular galaxy
A barred irregular galaxy is an irregular version of a barred spiral galaxy. Examples include the Large Magellanic Cloud and NGC 6822. Some barred irregular galaxies (like the Large Magellanic Cloud) may be dwarf spiral galaxies, which have been ...
in the constellation
Leo Minor. The galaxy lies about 80 million
light years away from Earth, which means, given its apparent dimensions, that NGC 3396 is approximately 85,000 light years across.
It was discovered by
William Herschel on December 7, 1785.
Characteristics
NGC 3396 forms an interacting pair with NGC 3395, a
spiral galaxy
Spiral galaxies form a class of galaxy originally described by Edwin Hubble in his 1936 work ''The Realm of the Nebulae''[tidal tail
A tidal tail is a thin, elongated region of stars and interstellar gas that extends into space from a galaxy. Tidal tails occur as a result of galactic tide forces between interacting galaxies. Examples of galaxies with tidal tails include the ...]
s are observed. Dynamical modelling of the pair suggests that the two galaxies had a first close encounter in the past, which resulting in gas been stripped from NGC 3395 and forming a tidal tail to the south-east.
A second close encounter took place about 50 million years ago, resulting to
starburst activity. The two galaxies will most likely
merge in the next 500 million years.
The galaxy hosts a number of
HII region
An H II region or HII region is a region of interstellar atomic hydrogen that is ionized. It is typically in a molecular cloud of partially ionized gas in which star formation has recently taken place, with a size ranging from one to hundreds ...
s that are star forming
with the region of most intense
being in the center of the galaxy.
The average size of the knots in NGC 3396 is an order of magnitude larger than those in NGC 3395. The central region of NGC 3396 is estimated to host 1,000 to 2,000
Wolf-Rayet stars and tens of thousands of
O-type stars.
The star formation rate in the circumnuclear is estimated to be 0.15 per year and in the rest of the galaxy 0.39 .
The nucleus of the galaxy has been found to be
active and based on its spectrum it has been categorised as a
LINER
A low-ionization nuclear emission-line region (LINER) is a type of galactic nucleus that is defined by its spectral line emission. The spectra typically include line emission from weakly ionized or neutral atoms, such as O, O+, N+, and S+. ...
.
Kinematic analysis of the gas indicates there is gas inflow to the centre of the galaxy along its bar and also there is an biconal outflow element that could be
galactic wind from a
supermassive black hole in the nucleus.
Nearby galaxies
The NGC 3395/3396 pair is part of the NGC 3430 Group or LGG 218. Other members of the group include the galaxies
NGC 3381
NGC commonly refers to:
* New General Catalogue of Nebulae and Clusters of Stars, a catalogue of deep sky objects in astronomy
NGC may also refer to:
Companies
* NGC Corporation, name of US electric company Dynegy, Inc. from 1995 to 1998
* Nati ...
,
NGC 3424
NGC commonly refers to:
* New General Catalogue of Nebulae and Clusters of Stars, a catalogue of deep sky objects in astronomy
NGC may also refer to:
Companies
* NGC Corporation, name of US electric company Dynegy, Inc. from 1995 to 1998
* Nati ...
,
NGC 3430
NGC commonly refers to:
* New General Catalogue of Nebulae and Clusters of Stars, a catalogue of deep sky objects in astronomy
NGC may also refer to:
Companies
* NGC Corporation, name of US electric company Dynegy, Inc. from 1995 to 1998
* Nat ...
,
NGC 3442
NGC commonly refers to:
* New General Catalogue of Nebulae and Clusters of Stars, a catalogue of deep sky objects in astronomy
NGC may also refer to:
Companies
* NGC Corporation, name of US electric company Dynegy, Inc. from 1995 to 1998
* Nat ...
, and
IC 2604. IC 2604 lies 14 arcmin to the south-west of the pair and
IC 2608 14 arcmin to the south-east.
The group is part 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 ...
, which is part of the
Virgo Supercluster.
References
External links
{{Leo Minor
Barred irregular galaxies
Interacting galaxies
Peculiar galaxies
Leo Minor
3396
05935
270
__NOTOC__
Year 270 ( CCLXX) was a common year starting on Saturday (link will display the full calendar) of the Julian calendar. At the time, it was known as the Year of the Consulship of Antiochianus and Orfitus (or, less frequently, year 102 ...
+06-24-018
32434
Discoveries by William Herschel
Astronomical objects discovered in 1785