NGC 6166 | |
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![]() NGC 6166 by Spitzer Space Telescope | |
Observation data (J2000 epoch) | |
Constellation | Hercules |
Right ascension | 16h 28m 38.276s |
Declination | +39° 33′ 04.97″ |
Redshift | z = −0.030354 (minus sign indicates blueshift ) |
Heliocentric radial velocity | −9100 km/s |
Distance | 490 Mly (142 Mpc) |
Apparent magnitude (V) | 12.78 [1] |
Absolute magnitude (V) | −24.1 |
Characteristics | |
Type | cD2 pec. |
Apparent size (V) | 1.9’ x 1.4’ |
Other designations | |
UGC 10409, PGC 58265, CGCG 2205.6+3107 0504, MCG +07-34-060, 3C 338 |
NGC 6166 is an elliptical galaxy in the Abell 2199 cluster. It lies 490 million light years away in the constellation Hercules. The primary galaxy in the cluster, it is one of the most luminous galaxies known in terms of X-ray emissions. [2]
NGC 6166 is a supermassive, type cD galaxy, with several smaller galaxies within its envelope. [3]
Suspected to have formed through a number of galaxy collisions, NGC 6166 has a large number of globular clusters (estimated as between 6,200 and 22,000 in 1996) [4] orbiting the galaxy. [5] A 2016 study, however, gave an even higher number (around 39,000) suggesting also that the halo of this galaxy blends smoothly with the intra-cluster medium. [6] Because of that, the galaxy has the richest globular cluster system known. The galaxy harbors a supermassive black hole at its center with a mass of nearly 30 billion M☉ based on dynamical modelling. [7]
NGC 6166 is known to host an active nucleus, classified as an FR I source, which powers two symmetric parsec-scale radio jets and radio lobes. These are caused by the infall of gas into its center due to a cooling flow that deposits 200 solar masses of gas every year there. [8]
It has been proposed that a number of O-type stars may be present in the center of NGC 6166. [9] [10]
The Virgo Cluster is a large cluster of galaxies whose center is 53.8 ± 0.3 Mly away in the constellation Virgo. Comprising approximately 1,300 member galaxies, the cluster forms the heart of the larger Virgo Supercluster, of which the Local Group is a member. The Local Group actually experiences the mass of the Virgo Supercluster as the Virgocentric flow. It is estimated that the Virgo Cluster's mass is 1.2×1015M☉ out to 8 degrees of the cluster's center or a radius of about 2.2 Mpc.
Messier 87 is a supergiant elliptical galaxy in the constellation Virgo that contains several trillion stars. One of the largest and most massive galaxies in the local universe, it has a large population of globular clusters—about 15,000 compared with the 150–200 orbiting the Milky Way—and a jet of energetic plasma that originates at the core and extends at least 1,500 parsecs, traveling at a relativistic speed. It is one of the brightest radio sources in the sky and a popular target for both amateur and professional astronomers.
The Sombrero Galaxy is a peculiar galaxy of unclear classification in the constellation borders of Virgo and Corvus, being about 9.55 megaparsecs from the Milky Way galaxy. It is a member of the Virgo II Groups, a series of galaxies and galaxy clusters strung out from the southern edge of the Virgo Supercluster. It has an isophotal diameter of approximately 29.09 to 32.32 kiloparsecs, making it slightly bigger in size than the Milky Way.
Messier 89 is an elliptical galaxy in the constellation Virgo. It was discovered by Charles Messier on March 18, 1781. M89 is a member of the Virgo Cluster of galaxies.
NGC 1569 is a dwarf irregular galaxy in Camelopardalis. The galaxy is relatively nearby and consequently, the Hubble Space Telescope can easily resolve the stars within the galaxy. The distance to the galaxy was previously believed to be only 2.4 Mpc. However, in 2008 scientists studying images from Hubble calculated the galaxy's distance at nearly 11 million light-years away, about 4 million light-years farther than previously thought, meaning it is a member of the IC 342 group of galaxies.
A super star cluster (SSC) is a very massive young open cluster that is thought to be the precursor of a globular cluster. These clusters called "super" because they are relatively more luminous and contain more mass than other young star clusters. The SSC, however, does not have to physically be larger than other clusters of lower mass and luminosity. They typically contain a very large number of young, massive stars that ionize a surrounding HII region or a so-called "Ultra dense HII region (UDHII)" in the Milky Way Galaxy or in other galaxies. An SSC's HII region is in turn surrounded by a cocoon of dust. In many cases, the stars and the HII regions will be invisible to observations in certain wavelengths of light, such as the visible spectrum, due to high levels of extinction. As a result, the youngest SSCs are best observed and photographed in radio and infrared. SSCs, such as Westerlund 1 (Wd1), have been found in the Milky Way Galaxy. However, most have been observed in farther regions of the universe. In the galaxy M82 alone, 197 young SSCs have been observed and identified using the Hubble Space Telescope.
NGC 1023, also known as the Perseus Lenticular Galaxy, is a barred lenticular galaxy, a member of the NGC 1023 group of galaxies in the Local Supercluster. Distance measurements vary from 9.3 to 19.7 million parsecs (30 to 64 million light-years). The supermassive black hole at the core has a mass of (4.4±0.5)×107 M☉. The black hole was discovered by analyzing the dynamics of the galaxy.
NGC 1404 is an elliptical galaxy in the Southern constellation Eridanus. It was discovered on November 28, 1837, by the astronomer John Herschel. Based on the tip of the red-giant branch distance indicator, it lies at a distance of approximately 60 million light-years from the Milky Way. It is one of the brightest members of the Fornax Cluster.
Abell 2199 is a galaxy cluster in the Abell catalogue featuring the brightest cluster galaxy NGC 6166, a cD galaxy. Abell 2199 is the definition of a Bautz-Morgan type I cluster due to NGC 6166.
NGC 4494 is an elliptical galaxy located in the constellation Coma Berenices. It is located at a distance of circa 45 million light years from Earth, which, given its apparent dimensions, means that NGC 4494 is about 60,000 light years across. It was discovered by William Herschel in 1785.
The Gaia Sausage or Gaia Enceladus is the remains of a dwarf galaxy that merged with the Milky Way about 8–11 billion years ago. At least eight globular clusters were added to the Milky Way along with 50 billion solar masses of stars, gas and dark matter. It represents the last major merger of the Milky Way.
NGC 708 is an elliptical galaxy located 240 million light-years away in the constellation Andromeda and was discovered by astronomer William Herschel on September 21, 1786. It is classified as a cD galaxy and is the brightest member of Abell 262. NGC 708 is a weak FR I radio galaxy and is also classified as a type 2 Seyfert galaxy.
NGC 5982 is an elliptical galaxy located in the constellation Draco. It is located at a distance of circa 130 million light years from Earth, which, given its apparent dimensions, means that NGC 5982 is about 100,000 light years across. It was discovered by William Herschel on May 25, 1788.
NGC 4636 is an elliptical galaxy located in the constellation Virgo. It is a member of the NGC 4753 Group of galaxies, which is a member of the Virgo II Groups, a series of galaxies and galaxy clusters strung out from the southern edge of the Virgo Supercluster. It is located at a distance of about 55 million light years from Earth, which, given its apparent dimensions, means that NGC 4636 is about 105,000 light years across.
NGC 5846 is an elliptical galaxy located in the constellation Virgo. It is located at a distance of circa 90 million light years from Earth, which, given its apparent dimensions, means that NGC 5846 is about 110,000 light years across. It was discovered by William Herschel on February 24, 1786. It lies near 110 Virginis and is part of the Herschel 400 Catalogue. It is a member of the NGC 5846 Group of galaxies, itself one of the Virgo III Groups strung out to the east of the Virgo Supercluster of galaxies.
IC 1459 is an elliptical galaxy located in the constellation Grus. It is located at a distance of circa 85 million light-years from Earth, which, given its apparent dimensions, means that IC 1459 is about 130,000 light-years across. It was discovered by Edward Emerson Barnard in 1892.
NGC 4278 is an elliptical galaxy located in the constellation Coma Berenices. It is located at a distance of circa 55 million light years from Earth, which, given its apparent dimensions, means that NGC 4278 is about 65,000 light years across. It was discovered by William Herschel on March 13, 1785. NGC 4278 is part of the Herschel 400 Catalogue and can be found about one and 3/4 of a degree northwest of Gamma Comae Berenices even with a small telescope.
NGC 1549 is an elliptical galaxy located in the constellation Dorado. It is located at a distance of about 50 million light years from Earth, which, given its apparent dimensions, means that NGC 1549 is about 75,000 light years across. NGC 1549 was discovered by John Herschel on 6 December 1835 and may have been observed by James Dunlop in 1826. It is a member of the Dorado Group.
NGC 545 is a lenticular galaxy located in the constellation Cetus. It is located at a distance of about 250 million light years from Earth, which, given its apparent dimensions, means that NGC 545 is about 180,000 light years across. It was discovered by William Herschel on October 1, 1785. It is a member of the Abell 194 galaxy cluster and is included along with NGC 547 in the Atlas of Peculiar Galaxies.
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