Messier 108
Encyclopedia
Messier 108 is a barred spiral galaxy
in the constellation
Ursa Major. It was discovered by Pierre Méchain
in 1781 or 1782. From the perspective of the Earth, this galaxy is seen almost edge-on.
This galaxy is an isolated member of the Ursa Major Cluster
cluster of galaxies in the Virgo supercluster
. It has a morphological classification of type SBbc in the de Vaucouleurs system, which means it is a barred spiral galaxy with somewhat loosely wound arms. The maximum angular size of the galaxy in the optical band is 11′.1 × 4′.6, and it is inclined 75° to the line of sight.
This galaxy has an estimated mass of 125 billion times the mass of the Sun
and includes about 290 ± 80 globular cluster
s. Examination of the distribution of neutral hydrogen in this galaxy shows shells of expanding gas extending for several kiloparsecs, known as H1 supershells. These may be driven by bursts of star formation activity, resulting in supernovae explosions. Alternatively they may result from an infall of gas from outside the galaxy or by radio jets.
Observations with the Chandra X-ray Observatory
have identified 83 X-ray
sources, including a source located at the nucleus. The brightest of these sources may be an intermediate-mass black hole that is accreting matter. The galaxy is also emitting a diffuse soft X-ray radiation within 10 kpc of the optical galaxy. The spectrum of the X-ray source at the core is consistent with an active galactic nucleus
, but an examination with the Spitzer Space Telescope
shows no indication of activity. The supermassive black hole
at the core has an estimated mass equal to 24 million times the mass of the Sun.
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...
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....
Ursa Major. It was discovered by Pierre Méchain
Pierre Méchain
Pierre François André Méchain was a French astronomer and surveyor who, with Charles Messier, was a major contributor to the early study of deep sky objects and comets.-Life:...
in 1781 or 1782. From the perspective of the Earth, this galaxy is seen almost edge-on.
This galaxy is an isolated member of the Ursa Major Cluster
Ursa Major cluster
The Ursa Major Cluster is a spiral-rich galaxy cluster of the Virgo Supercluster.One of its biggest galaxies are NGC 3631, NGC 3953, M109 on North and NGC 3726, NGC 3938 NGC 4051 on South....
cluster of galaxies in the Virgo supercluster
Virgo Supercluster
The Virgo Supercluster or Local Supercluster is the irregular supercluster that contains the Virgo Cluster in addition to the Local Group, which in turn contains the Milky Way and Andromeda galaxies. At least 100 galaxy groups and clusters are located within its diameter of 33 megaparsecs...
. It has a morphological classification of type SBbc in the de Vaucouleurs system, which means it is a barred spiral galaxy with somewhat loosely wound arms. The maximum angular size of the galaxy in the optical band is 11′.1 × 4′.6, and it is inclined 75° to the line of sight.
This galaxy has an estimated mass of 125 billion times the mass of the Sun
Solar mass
The solar mass , , is a standard unit of mass in astronomy, used to indicate the masses of other stars and galaxies...
and includes about 290 ± 80 globular cluster
Globular cluster
A globular cluster is a spherical collection of stars that orbits a galactic core as a satellite. Globular clusters are very tightly bound by gravity, which gives them their spherical shapes and relatively high stellar densities toward their centers. The name of this category of star cluster is...
s. Examination of the distribution of neutral hydrogen in this galaxy shows shells of expanding gas extending for several kiloparsecs, known as H1 supershells. These may be driven by bursts of star formation activity, resulting in supernovae explosions. Alternatively they may result from an infall of gas from outside the galaxy or by radio jets.
Observations with the Chandra X-ray Observatory
Chandra X-ray Observatory
The Chandra X-ray Observatory is a satellite launched on STS-93 by NASA on July 23, 1999. It was named in honor of Indian-American physicist Subrahmanyan Chandrasekhar who is known for determining the maximum mass for white dwarfs. "Chandra" also means "moon" or "luminous" in Sanskrit.Chandra...
have identified 83 X-ray
X-ray
X-radiation is a form of electromagnetic radiation. X-rays have a wavelength in the range of 0.01 to 10 nanometers, corresponding to frequencies in the range 30 petahertz to 30 exahertz and energies in the range 120 eV to 120 keV. They are shorter in wavelength than UV rays and longer than gamma...
sources, including a source located at the nucleus. The brightest of these sources may be an intermediate-mass black hole that is accreting matter. The galaxy is also emitting a diffuse soft X-ray radiation within 10 kpc of the optical galaxy. The spectrum of the X-ray source at the core is consistent with an active galactic nucleus
Active galactic nucleus
An active galactic nucleus is a compact region at the centre of a galaxy that has a much higher than normal luminosity over at least some portion, and possibly all, of the electromagnetic spectrum. Such excess emission has been observed in the radio, infrared, optical, ultra-violet, X-ray and...
, but an examination with the Spitzer Space Telescope
Spitzer Space Telescope
The Spitzer Space Telescope , formerly the Space Infrared Telescope Facility is an infrared space observatory launched in 2003...
shows no indication of activity. The 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 the core has an estimated mass equal to 24 million times the mass of the Sun.
See also
- NGC 2403NGC 2403NGC 2403 is an intermediate spiral galaxy in the constellation Camelopardalis. NGC 2403 is an outlying member of the M81 Group, and is approximately 8 million light-years distant...
- a similar spiral galaxy - NGC 4631NGC 4631NGC 4631 is an edge-on spiral galaxy in the constellation Canes Venatici. This galaxy's slightly distorted wedge shape gives it the appearance of a herring or a whale, whence its nickname...
- a similar spiral galaxy - NGC 7793NGC 7793NGC 7793 is a spiral galaxy about 12.7 million light-years away in the constellation Sculptor. It was discovered in 1826 by James Dunlop.-Galaxy group information:...
- a similar spiral galaxy