NGC 7674 | |
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Observation data (J2000 epoch) | |
Constellation | Pegasus |
Right ascension | 23h 27m 56.7s [1] |
Declination | +08° 46′ 45″ [1] |
Redshift | 0.028924 ± 0.000030 [1] |
Heliocentric radial velocity | 8,671 ± 9 km/s [1] |
Distance | 380 Mly (117 Mpc) [1] |
Apparent magnitude (V) | 13.1 [2] |
Characteristics | |
Type | SA(r)bc pec [1] |
Apparent size (V) | 1.1′ × 1.0′ [1] |
Notable features | Seyfert galaxy |
Other designations | |
Arp 182, UGC 12608, MCG +01-59-080, Mrk 533, PGC 71504, CGCG 406-112, VV 343a [1] |
NGC 7674 is a spiral galaxy located in the constellation Pegasus. It is located at a distance of about 350 million light years from Earth, which, given its apparent dimensions, means that NGC 7674 is about 125,000 light years across. It was discovered by John Herschel on August 16, 1830. [3]
The galaxy is seen nearly face-on, at an inclination of 31 degrees. The central bar-shaped structure, measuring 15×5 arcseconds is made up of stars. The galaxy has two spiral arms that become broader as the distance increases. One arm vanishes at the point it overlaps with the nearby galaxy NGC 7674A. The shape of NGC 7674, including the long narrow streamers emanating northeast and northwest of the galaxy can be accounted for by tidal interactions with its companions. There is no dwarf galaxy seen inside the streamers. [4] It is featured in Arp's Atlas of Peculiar Galaxies as number 182, in the category "galaxies with narrow filaments". [5]
NGC 7674 has a powerful active nucleus of the kind known as a type 2 Seyfert that is perhaps fed by gas drawn into the center through the interactions with the companions. [5] In 1975, observations of excess ultraviolet emission led to designation as Markarian 533 in Markarian's catalog. [6] Later, using spectropolarimetry, emission characteristic of a hidden broad-line region (BLR), visible only in the polarized flux spectrum was detected, implying that the nucleus of NGC 7674 is an obscured type 1 Seyfert, hidden by a dust torus. [7] In the center of NGC 7674 lies a supermassive black hole whose mass is estimated to be nearly 3.63×107 M☉ based on stellar velocity dispersion. [8] When observed in radio waves, NGC 7674 features two radio jets with an S-shape, 0.7 kpc long. The reason for this shape may be a change in the black hole spin axis due to a minor merger, the presence of a binary black hole or due to interactions with the interstellar medium. [9] Two radio sources with characteristics similar to accreting supermassive black holes have been observed in the centre of NGC 7674, at a projected separation of 0.35 parsec. [10]
NGC 7674 falls into the family of luminous infrared galaxies, with its infrared luminosity being 1011.54 L☉. [11] The luminous infrared galaxies are characterised by intense star forming activity. The total star formation rate in NGC 7674 is estimated to be 54 M☉ per year, and the star formation rate at the nucleus is 4.3 M☉ per year. [9]
Two supernovae have been observed in NGC 7674, SN 2011ee (type Ic, mag 18.6) and SN 2011hb (type Ia, mag 18.8). [12]
NGC 7674 is the brightest and largest member of the isolated Hickson 96 compact group of galaxies, consisting of four galaxies. NGC 7674 forms a pair with its smaller companion NGC 7674A, which lies 34 arcseconds to the north. NGC 7675, an elliptical galaxy, lies 2.2 arcminutes to the east. [4] [13]
Seyfert galaxies are one of the two largest groups of active galaxies, along with quasar host galaxies. They have quasar-like nuclei with very high surface brightnesses whose spectra reveal strong, high-ionisation emission lines, but unlike quasars, their host galaxies are clearly detectable.
NGC 4395 is a nearby low surface brightness spiral galaxy located about 14 million light-years from Earth in the constellation Canes Venatici. The nucleus of NGC 4395 is active and the galaxy is classified as a Seyfert Type I known for its very low-mass supermassive black hole. It is one of the lowest
NGC 7469 is an intermediate spiral galaxy in the constellation of Pegasus. NGC 7469 is located about 200 million light-years away from Earth, which means, given its apparent dimensions, that NGC 7469 is approximately 90,000 light-years across. It was discovered by William Herschel on November 12, 1784.
NGC 3367 is a barred spiral galaxy located in the constellation Leo. It is located at a distance of about 120 million light years from Earth, which, given its apparent dimensions, means that NGC 3367 is about 85,000 light years across. It was discovered by William Herschel on March 19, 1784.
NGC 7130 is a spiral galaxy located in the constellation Piscis Austrinus. It is located at a distance of about 220 million light years from Earth, which, given its apparent dimensions, means that NGC 7130 is about 100,000 light years across. It was discovered by John Herschel on September 25, 1834, and discovered independently by Lewis Swift on September 17, 1897. The location of the galaxy given in the New General Catalogue was off by 30 arcminutes in declination from the location of the 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 985 is a ring galaxy in the constellation of Cetus. It is located about 550 million light years away from Earth, which means, given its apparent dimensions, that NGC 985 is approximately 160,000 light years across. It was discovered by Francis Leavenworth in 1886. It is a type 1 Seyfert galaxy.
NGC 6951 is a barred spiral galaxy located in the constellation Cepheus. It is located at a distance of about 75 million light-years from Earth, which, given its apparent dimensions, means that NGC 6951 is about 100,000 light-years across. It was discovered by Jérôme Eugène Coggia in 1877 and independently by Lewis Swift in 1878.
NGC 5363 is a lenticular galaxy located in the constellation Virgo. It is located at a distance of circa 65 million light years from Earth, which, given its apparent dimensions, means that NGC 5363 is about 100,000 light years across. It was discovered by William Herschel on January 19, 1784. It is a member of the NGC 5364 Group of galaxies, itself one of the Virgo III Groups strung out to the east of the Virgo Supercluster of galaxies.
NGC 2273 is a barred spiral galaxy located in the constellation Lynx. It is located at a distance of circa 95 million light years from Earth, which, given its apparent dimensions, means that NGC 2273 is about 100,000 light years across. It was discovered by Nils Dunér on September 15, 1867.
NGC 2974 is a lenticular galaxy located in the constellation Sextans. It is located at a distance of circa 90 million light years from Earth, which, given its apparent dimensions, means that NGC 2974 is about 90,000 light years across. It was discovered by William Herschel on January 6, 1785. NGC 2974 is located in the sky about 2 and a half degrees south-south east of Iota Hydrae and more than 6 degrees northeast of Alphard. A 10th magnitude star lies next to the galaxy, thus making it a challenging object at low magnifications. NGC 2974 is part of the Herschel 400 Catalogue.
NGC 1241 is a spiral galaxy located in the constellation Eridanus. It is located at a distance of circa 150 million light years from Earth, which, given its apparent dimensions, means that NGC 1241 is about 140,000 light years across. It was discovered by William Herschel on January 10, 1785. It is classified as a Seyfert galaxy.
NGC 1142 is a distorted spiral galaxy in the constellation of Cetus. It is located about 370 million light years away from Earth, which means, given its apparent dimensions, that NGC 1142 is approximately 170,000 light years across. It is a type 2 Seyfert galaxy. It interacts with the elliptical galaxy NGC 1141.
NGC 7592 is an interacting galaxy system located 300 million light years away in the constellation Aquarius. It was discovered by William Herschel on September 20, 1784. The total infrared luminosity is 1011.33 L☉, and thus it is categorised as a luminous infrared galaxy. One of the galaxies hosts a type 2 Seyfert nucleus.
NGC 7679 is a lenticular galaxy with a peculiar morphology in the constellation Pisces. It is located at a distance of about 200 million light years from Earth, which, given its apparent dimensions, means that NGC 7679 is about 60,000 light years across. It was discovered by Heinrich d'Arrest on September 23, 1864. The total infrared luminosity is 1011.05 L☉, and thus it is categorised as a luminous infrared galaxy. NGC 7679 is both a starburst galaxy and a Seyfert galaxy.
Markarian 273 is a galaxy merger located in the constellation Ursa Major. It is located at a distance of about 500 million light years from Earth, which, given its apparent dimensions, means that Markarian 273 is about 130,000 light years across. It is an ultraluminous infrared galaxy and a Seyfert galaxy.
UGC 5101 is a galaxy merger located in the constellation Ursa Major. It is located at a distance of about 530 million light years from Earth. It is an ultraluminous infrared galaxy. The total infrared luminosity of the galaxy is estimated to be 1011.95 L☉ and the galaxy has a total star formation rate of 105 M☉ per year.
NGC 5135 is a barred spiral galaxy located in the constellation Hydra. It is located at a distance of about 200 million light years from Earth. It was discovered by John Herschel on May 8, 1834. It is a Seyfert galaxy.
NGC 5953 is a peculiar spiral galaxy in the constellation Serpens. The galaxy lies about 80 million light years away from Earth, which means, given its apparent dimensions, that NGC 5953 is approximately 35,000 light years across. It was discovered by William Herschel on April 17, 1784. NGC 5953 interacts with NGC 5954 forming a pair known as Arp 91.
NGC 7682 is a barred spiral galaxy in the constellation Pisces. It is located at a distance of about 180 million light years from Earth, which, given its apparent dimensions, means that NGC 7682 is about 65,000 light years across. It was discovered by Heinrich d'Arrest on September 23, 1864.