NGC 1097
Encyclopedia
NGC 1097 is a barred spiral galaxy
about 45 million
light-year
s away in the constellation
Fornax
. As of 2006, three supernova
e (SN 1992bd
, SN 1999eu
, and SN 2003B
) have been observed in NGC 1097.
NGC 1097 is also a Seyfert galaxy
. Deep photographs by Wolstencroft & Zealey (1975), Arp (1976),
and Lorre (1978) revealed four narrow optical jets that appear to emanate from the nucleus. Arp interpreted these as
manifestations of the (currently weak) active nucleus. Subsequent analysis of the brightest jet's radio-to-X-ray
spectral energy distribution by Carter, Allen & Malin (1984), Wehrle, Keel, & Jones (1997) and Higdon & Wallin (2003) were
able to rule out synchrotron and thermal free-free emission. The jets are in fact composed of stars. The failure to detect
atomic hydrogen gas in the jets (under the assumption that they were an example of tidal tails) using deep 21 cm
HI imaging with the Very Large Array radio telescope and numerical simulations led to the current interpretation that the jets are actually the shattered remains of a cannibalized dwarf galaxy (Higdon & Wallin 2003).
Like most massive galaxies, NGC 1097 has a supermassive black hole
at its center. Around the central black hole is a ring of star
-forming regions with a network of gas and dust that spirals from the ring to the black hole.
NGC 1097 has two satellite galaxies
. Dwarf elliptical galaxy NGC 1097A is the larger of the two. It is a peculiar elliptical galaxy
that orbits 42,000 light-years from the center of NGC 1097. Dwarf galaxy NGC 1097B, the outermost one,
was discovered by its HI emission (5 x 10^6 solar masses; Higdon & Wallin 2003), and appears to be a typical dwarf irregular.
Little else is known about it.
Barred spiral galaxy
A barred spiral galaxy is a spiral galaxy with a central bar-shaped structure composed of stars. Bars are found in approximately two-thirds of all spiral galaxies...
about 45 million
1 E22 m
To help compare different orders of magnitude, this page lists distances starting at 10 Zm .Distances shorter than 10 Zm* 24 Zm — 2.5 million light years — Distance to the Andromeda Galaxy...
light-year
Light-year
A light-year, also light year or lightyear is a unit of length, equal to just under 10 trillion kilometres...
s away in the constellation
Constellation
In modern astronomy, a constellation is an internationally defined area of the celestial sphere. These areas are grouped around asterisms, patterns formed by prominent stars within apparent proximity to one another on Earth's night sky....
Fornax
Fornax
Fornax is a constellation in the southern sky. Its name is Latin for furnace. It was created in the 18th century and is now one of the 88 modern constellations.-History:Fornax was formed by Nicolas Louis de Lacaille in 1756...
. As of 2006, three supernova
Supernova
A supernova is a stellar explosion that is more energetic than a nova. It is pronounced with the plural supernovae or supernovas. Supernovae are extremely luminous and cause a burst of radiation that often briefly outshines an entire galaxy, before fading from view over several weeks or months...
e (SN 1992bd
SN 1992bd
SN 1992bd was a supernova that happened in NGC 1097.-External links:*...
, SN 1999eu
SN 1999eu
SN 1999eu was a supernova that happened in NGC 1097. 23"E and 157"S of NGC 1097.-External links:*...
, and SN 2003B
SN 2003B
SN 2003B was a supernova that happened in NGC 1097 on January 5, 2003. It was a type II supernova....
) have been observed in NGC 1097.
NGC 1097 is also a Seyfert galaxy
Seyfert galaxy
Seyfert galaxies are a class of galaxies with nuclei that produce spectral line emission from highly ionized gas, named after Carl Keenan Seyfert, the astronomer who first identified the class in 1943...
. Deep photographs by Wolstencroft & Zealey (1975), Arp (1976),
and Lorre (1978) revealed four narrow optical jets that appear to emanate from the nucleus. Arp interpreted these as
manifestations of the (currently weak) active nucleus. Subsequent analysis of the brightest jet's radio-to-X-ray
spectral energy distribution by Carter, Allen & Malin (1984), Wehrle, Keel, & Jones (1997) and Higdon & Wallin (2003) were
able to rule out synchrotron and thermal free-free emission. The jets are in fact composed of stars. The failure to detect
atomic hydrogen gas in the jets (under the assumption that they were an example of tidal tails) using deep 21 cm
HI imaging with the Very Large Array radio telescope and numerical simulations led to the current interpretation that the jets are actually the shattered remains of a cannibalized dwarf galaxy (Higdon & Wallin 2003).
Like most massive galaxies, NGC 1097 has a supermassive black hole
Supermassive black hole
A supermassive black hole is the largest type of black hole in a galaxy, in the order of hundreds of thousands to billions of solar masses. Most, and possibly all galaxies, including the Milky Way, are believed to contain supermassive black holes at their centers.Supermassive black holes have...
at its center. Around the central black hole is a ring of star
Star
A star is a massive, luminous sphere of plasma held together by gravity. At the end of its lifetime, a star can also contain a proportion of degenerate matter. The nearest star to Earth is the Sun, which is the source of most of the energy on Earth...
-forming regions with a network of gas and dust that spirals from the ring to the black hole.
NGC 1097 has two satellite galaxies
Satellite galaxy
A satellite galaxy orbits a larger galaxy due to gravitational attraction. Although a galaxy is made of a large number of objects which are not connected to each other, it has a center of mass, which represents a weighted average of the positions of each component object...
. Dwarf elliptical galaxy NGC 1097A is the larger of the two. It is a peculiar elliptical galaxy
Elliptical galaxy
An elliptical galaxy is a galaxy having an approximately ellipsoidal shape and a smooth, nearly featureless brightness profile. They range in shape from nearly spherical to highly flat and in size from hundreds of millions to over one trillion stars...
that orbits 42,000 light-years from the center of NGC 1097. Dwarf galaxy NGC 1097B, the outermost one,
was discovered by its HI emission (5 x 10^6 solar masses; Higdon & Wallin 2003), and appears to be a typical dwarf irregular.
Little else is known about it.
External links
- VLT observations – NGC 1097's "dog-leg" tidal stream
- weblore.com – NGC 1097: The Galaxy with the Longest known Optical Jets
- Antilhue-Chile – NGC 1097 in Fornax
- ESO – Very Large Telescope observations of NGC 1097
- Astronomy Picture of the Day – In the Arms of NGC 1097 (2006-12-01)