3C 285 | |
---|---|
Observation data (J2000 epoch) | |
Constellation | Canes Venatici |
Right ascension | 13h 21m 17.813s [1] |
Declination | +42° 35′ 15.38″ [1] |
Redshift | 0.0794 [2] |
Helio radial velocity | 23,799 ± 5 km/s [2] |
Distance | 323 megaparsecs (1.05×109 ly) h −1 0.73 [2] |
Apparent magnitude (V) | 16.23 [1] |
Characteristics | |
Type | rG, Rad, AGN, G, GiG, QSO [1] G, FR II [2] |
Apparent size (V) | 0.417' x 0.242' [1] |
Other designations | |
DA 343, LEDA 46625, 3C 285, 4C +42.37, 2MASX J13211781+4235153 |
3C 285 is a radio galaxy located in the constellation Canes Venatici. It is located about 1 bilion light years away. It is a Fanaroff-Riley 2 radio galaxy and is hosted in a disturbed spiral galaxy. [3]
3C 285 is the brightest member of a small galaxy group. Its morphology is peculiar, with an S-shaped envelope that points to another galaxy of the group, located to the northwest. A gas filament 26 arcseconds long extends towards that galaxy. [4] In optical and ultraviolet observations the galaxy features dust lanes, two across the galaxy and one perpendicular to them that also obscures part of the nucleus. Along the edges of the dust lanes knots of elevated ultraviolet emission indicate locations of where new stars are formed. [5] In the centre of 3C 285 lies a supermassive black hole whose mass is estimated to be 107.70±0.10 (40-63 million) M☉ based on stellar velocity dispersion. [6]
When observed in radiowaves, 3C 285 has two lobes with filamentary structures in them, and a jet is visible in the eastern lobe. A blue star forming region, named 3C 285/09.6, has been detected within the eastern radio lobe, and it has been suggested that the star formation was induced by the compression of a region of dense intergalactic gas by the radio jet. [7] The gas mass of the region is estimated to be less than 6.2×108 M☉ based on CO imaging and so it is estimated to be depleted if star formation continues at the current rate in less than a bilion years. [8]
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NGC 541 is a lenticular galaxy located in the constellation Cetus. It is located at a distance of circa 230 million light years from Earth, which, given its apparent dimensions, means that NGC 541 is about 130,000 light years across. It was discovered by Heinrich d'Arrest on October 30, 1864. It is a member of the Abell 194 galaxy cluster and is included in the Atlas of Peculiar Galaxies in the category galaxies with nearby fragments. NGC 541 is a radio galaxy of Fanaroff-Riley class I, also known as 3C 40A.
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