Markarian 231 (UGC 8058) is a Type-1

Seyfert galaxy Seyfert galaxies are one of the two largest groups of active galaxies, along with quasars. They have quasar-like nuclei (very luminous, distant and bright sources of electromagnetic radiation) with very high surface brightnesses whose spectra ...

that was discovered in 1969 as part of a search of galaxies with strong

ultraviolet Ultraviolet (UV) is a form of electromagnetic radiation with wavelength from 10 nanometer, nm (with a corresponding frequency around 30 Hertz, PHz) to 400 nm (750 Hertz, THz), shorter than that of visible light, but longer than ...

radiation. It contains the nearest known

quasar A quasar is an extremely Luminosity, luminous active galactic nucleus (AGN). It is pronounced , and sometimes known as a quasi-stellar object, abbreviated QSO. This emission from a galaxy nucleus is powered by a supermassive black hole with a m ...

. Markarian 231 is located about 581 million

light years A light-year, alternatively spelled light year, is a large unit of length used to express astronomical distances and is equivalent to about 9.46 trillion kilometers (), or 5.88 trillion miles ().One trillion here is taken to be 1012 ...

away from

Earth Earth is the third planet from the Sun and the only astronomical object known to harbor life. While large volumes of water can be found throughout the Solar System, only Earth sustains liquid surface water. About 71% of Earth's surfa ...

, in the constellation of

Ursa Major Ursa Major (; also known as the Great Bear) is a constellation in the northern sky, whose associated mythology likely dates back into prehistory. Its Latin name means "greater (or larger) bear," referring to and contrasting it with nearby Ursa ...

Characteristics

The Markarian 231

galaxy A galaxy is a system of stars, stellar remnants, interstellar gas, dust, dark matter, bound together by gravity. The word is derived from the Greek ' (), literally 'milky', a reference to the Milky Way galaxy that contains the Solar System. ...

is undergoing an energetic starburst. A nuclear ring of active star formation has been found in the center with a rate of formation greater than 100

solar masses The solar mass () is a standard unit of mass in astronomy, equal to approximately . It is often used to indicate the masses of other stars, as well as stellar clusters, nebulae, galaxies and black holes. It is approximately equal to the mass of ...

per year. It is one of the most ultraluminous

infrared Infrared (IR), sometimes called infrared light, is electromagnetic radiation (EMR) with wavelengths longer than those of visible light. It is therefore invisible to the human eye. IR is generally understood to encompass wavelengths from around ...

galaxies with power derived from an accreting

black hole A black hole is a region of spacetime where gravitation, gravity is so strong that nothing, including light or other Electromagnetic radiation, electromagnetic waves, has enough energy to escape it. The theory of general relativity predicts t ...

in the center and the closest known

. A study in 2015 suggested that the central black hole, estimated to be 150 million times the mass of the Sun, may have a black hole companion weighing in at 4 million solar masses, and that the duo completed an orbit around each other every 1.2 years. However, that model has subsequently been shown to be unfeasible. Another study has found evidence for the presence of molecular

oxygen Oxygen is the chemical element with the symbol O and atomic number 8. It is a member of the chalcogen group in the periodic table, a highly reactive nonmetal, and an oxidizing agent that readily forms oxides with most elements as wel ...

(O₂) by using

submillimetre astronomy Submillimetre astronomy or submillimeter astronomy (see spelling differences) is the branch of observational astronomy that is conducted at submillimetre wavelengths (i.e., terahertz radiation) of the electromagnetic spectrum. Astronomers plac ...

, the first time molecular oxygen had been detected outside of the

Milky Way galaxy The Milky Way is the galaxy that includes our Solar System, with the name describing the galaxy's appearance from Earth: a hazy band of light seen in the night sky formed from stars that cannot be individually distinguished by the naked eye. ...

References

External links

Markarian 231 at ESA
''Quasar's Belch Solves Longstanding Mystery'', from Gemini North Observatory, ApJ March 2011, to be published. * Chang-Shuo Yan, Youjun Lu, Xinyu Dai, and Qingjuan Yu. "A probable milli-parsec supermassive binary black hole in the nearest quasar MRK 231" 2015 August 14 ''

The Astrophysical Journal ''The Astrophysical Journal'', often abbreviated ''ApJ'' (pronounced "ap jay") in references and speech, is a peer-reviewed Peer review is the evaluation of work by one or more people with similar competencies as the producers of the work ...

'', Vol. 809, Iss. 2 *http://www.cnn.com/2015/08/31/us/double-black-hole-nasa-hubble-feat/ *http://www.sci-news.com/astronomy/science-supermassive-binary-black-hole-markarian231-03180.html *http://dso-browser.com/dso/info/UGC/8058 Spiral galaxies Seyfert galaxies Luminous infrared galaxies 8058 Markarian galaxies 44117 Ursa Major (constellation) {{Spiral-galaxy-stub

Characteristics

See also

References

External links