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Disturbed Shape

#merging galaxies #MRK 231 #UGC 8058 #galaxy #Ursa Major

New Discovery Finds the Making of Gamma Ray Burst in Progress

Why is this important? Because the Earth has been hit by the surge of cosmic rays from a quasar (or supernova) at least 5 times in our historical past, and once in recent history during the year 774/775 AD (or CE). This event resulted in a stream of charged particles made up of cosmic rays and gamma radiation causing a “global” damage to Earth’s atmosphere.

A new discovery by astronomers using…

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#774/775 A.D.#gamma ray burst #Milky Way #milky way galaxy #mrk 231 #wr 104

Hubble Finds That the Nearest Quasar Is Powered by a Double Black Hole

Astronomers using NASA's Hubble Space Telescope have found that Markarian 231 (Mrk 231), the nearest galaxy to Earth that hosts a quasar, is powered by two central black holes furiously whirling about each other.

The finding suggests that quasars — the brilliant cores of active galaxies — may commonly host two central supermassive black holes that fall into orbit about one another as a result of the merger between two galaxies. Like a pair of whirling skaters, the black-hole duo generates tremendous amounts of energy that makes the core of the host galaxy outshine the glow of the galaxy's population of billions of stars, which scientists then identify as quasars.

Scientists looked at Hubble archival observations of ultraviolet radiation emitted from the center of Mrk 231 to discover what they describe as "extreme and surprising properties."

If only one black hole were present in the center of the quasar, the whole accretion disk made of surrounding hot gas would glow in ultraviolet rays. Instead, the ultraviolet glow of the dusty disk abruptly drops off towards the center. This provides observational evidence that the disk has a big donut hole encircling the central black hole. The best explanation for the observational data, based on dynamical models, is that the center of the disk is carved out by the action of two black holes orbiting each other. The second, smaller black hole orbits in the inner edge of the accretion disk, and has its own mini-disk with an ultraviolet glow.

"We are extremely excited about this finding because it not only shows the existence of a close binary black hole in Mrk 231, but also paves a new way to systematically search binary black holes via the nature of their ultraviolet light emission," said Youjun Lu of the National Astronomical Observatories of China, Chinese Academy of Sciences.

"The structure of our universe, such as those giant galaxies and clusters of galaxies, grows by merging smaller systems into larger ones, and binary black holes are natural consequences of these mergers of galaxies," added co-investigator Xinyu Dai of the University of Oklahoma.

The central black hole is estimated to be 150 million times the mass of our sun, and the companion weighs in at 4 million solar masses. The dynamic duo completes an orbit around each other every 1.2 years.

The lower-mass black hole is the remnant of a smaller galaxy that merged with Mrk 231. Evidence of a recent merger comes from the host galaxy's asymmetry, and the long tidal tails of young blue stars.

The result of the merger has been to make Mrk 231 an energetic starburst galaxy with a star-formation rate 100 times greater than that of our Milky Way galaxy. The infalling gas fuels the black hole "engine," triggering outflows and gas turbulence that incites a firestorm of star birth.

The binary black holes are predicted to spiral together and collide within a few hundred thousand years.

Mrk 231 is located 581 million light-years away.

The results were published in the August 14, 2015, edition of The Astrophysical Journal.

#quasars #Mrk 231 #black holes

Hubble ziet twee superzware zwarte gaten in centrum van meest nabije quasar

Met de Hubble ruimtetelescoop is ontdekt dat zich in het centrum van Markarian 231 (Mrk 231) – met een afstand van ‘slechts’ 581 miljoen lichtjaar de meest nabij gelegen quasar – niet één superzwaar zwart gat bevindt, maar twee van die kolossale jongens, die om elkaar heen draaien. Quasars zijn de zeer lichtsterke kernen van sterrenstelsels, die een actief zwart gat in hun centrum hebben en deze ontdekking doet vermoeden dat quasars het product zijn van botsingen van sterrenstelsels, waardoor hun centrale superzware zwarte gaten botsen en samenkomen. De sterrenkundigen die Mrk 231 bestudeerden keken naar ultraviolette waarnemingen die met Hubble waren gedaan aan de quasar en ze ontdekten dat er iets vreemd was. Zou er één zwart gat in de kern van Mrk 231 zitten dan zou de gehele omringende accretieschijf rondom het zwarte gat UV-straling moeten uitzenden. Maar ze ontdekten dat nabij de kern van de accretieschijf de UV-straling abrupt stopt, zoals weergegeven in de afbeelding hieronder.

De daling in de UV-straling wordt veroorzaakt door de aanwezigheid van een tweede, kleiner superzwaar zwart gat, dat met z’n eigen accretieschijf een gat in de grotere accretieschijf heeft gemaakt. Schattingen geven aan dat het grootste zwart gat zo’n 150 miljoen zonsmassa’s zwaar is en het kleinere 4 miljoen zonsmassa’s – de laatste is vergelijkbaar met het zwarte gat in het centrum van de Melkweg. Ze draaien in slechts 1,2 jaar (!) om elkaar heen. Dat kleine zwarte gat is een overblijfsel van een sterrenstelsel waar Mrk 231 mee in botsing is gekomen. Daar zijn meer aanwijzingen voor, zoals de asymmetrische vorm van Mrk 231 en een lange ‘getijdenstaart’ vol met jonge, blauwe sterren. Hieronder een foto in optisch licht van Mrk 231, waarop dat goed te zien is.

Hier het vakartikel over deze ontdekking, dat op 14 augustus j.l. gepubliceerd is in The Astrophysical Journal. Bron: Hubble.

Astroblogs: http://www.astroblogs.nl/2015/08/28/hubble-ziet-twee-superzware-zwarte-gaten-centrum-van-meest-nabije-quasar/

#Hubble #Markarian 231 #Mrk 231

Astrophysicists Find Supermassive Black Holes in Quasar Nearest Earth

Astronomers using NASA’s Hubble Space Telescope have found that Markarian 231 (Mrk 231), the nearest galaxy to Earth that hosts a quasar, is powered by two central black holes furiously whirling about each other.

The finding suggests that quasars—the brilliant cores of active galaxies—may commonly host two central supermassive black holes that fall into orbit about one another as a result of…

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#black hole #Markarian #Milky Way #mrk 231 #quasar

Quasar's Outflow Solves Longstanding Mystery #science #space

Read the rest here: http://www.spacedaily.com/reports/Quasar_Belch_Solves_Longstanding_Mystery_999.html

Amplify’d from www.spacedaily.com

Quasar's Belch Solves Longstanding Mystery

Artist's conceptualization of the environment around the supermassive black hole at the center of Mrk 231. The broad outflow seen in the Gemini data is shown as the fan-shaped wedge at the top of the accretion disk around the black hole. This side-view is not what is seen from the Earth where we see it 'looking down the throat' of the outflow. A similar outflow is probably present under the disk as well and is hinted at in this illustration. The total amount of material entrained in the broad flow is at least 400 times the mass of the Sun per year. Note that a more localized, narrower jet is shown, this jet was known prior to the Gemini discovery of the broader outflow featured here. Credit:Gemini Observatory/AURA, artwork by Lynette Cook

For the first time, observations with the Gemini Observatory clearly reveal an extreme, large-scale galactic outflow that brings the cosmic dinner to a halt. The outflow is effectively blowing the galaxy apart in a negative feedback loop, depriving the galaxy's monstrous black hole of the gas and dust it needs to sustain its frenetic growth. It also limits the material available for the galaxy to make new generations of stars.

The groundbreaking work is a collaboration between David Rupke of Rhodes College in Tennessee and the University of Maryland's Sylvain Veilleux. The results are to be published in the March 10 issue of The Astrophysical Journal Letters and were completed with support from the U.S. National Science Foundation.

"This object is arguably the closest and best example that we know of a big galaxy in the final stages of a violent merger and in the process of shedding its cocoon and revealing a very energetic central quasar. This is really a last gasp of this galaxy; the black hole is belching its next meals into oblivion!"

According to Veilleux, Markarian 231 (Mrk 231), the galaxy observed with Gemini, is an ideal laboratory for studying outflows caused by feedback from supermassive black holes.

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