Keyword Tag Sort by


Categories: Astronomy Black Hole Gamma radiation Gamma-ray bursts GRBs Supermassive black hole

Extreme gamma radiation from black hole in a distant galaxy

An extremely powerful burst of gamma radiation has been observed in a distant galaxy. Usually gamma-ray bursts are seen as one burst from an exploding giant star. This new observation is a series of bursts of gamma radiation coming from the centre of a distant galaxy. The gamma radiation is most likely due to a star that has been swallowed up by a super massive black hole at the centre of the galaxy. The gamma radiation was observed with the Swift satellite by an international team of researchers including members from the Niels Bohr Institute and the results have been published in Science Express.

Gamma-ray-bursts are among the most extreme physical processes in the universe. When large, massive stars that are more than ten times as massive as the Sun die, there is an enormous supernova explosion, which in rare instances is accompanied by a powerful explosion of gamma radiation, called gamma-ray bursts, which typically last a few minutes. The new observation is not just one, but an entire series of gamma-ray bursts spread over several weeks.

Star blasted to bits

"We have localized the gamma radiation as coming from the centre of a small star-forming galaxy approximately 3.8 billion light years from the Earth”, explains Antonio de Ugarte Postigo, an astrophysicist at the Dark Cosmology Centre at the Niels Bohr Institute at the University of Copenhagen.

He explains that the it is most likely a case in which a star has come too close to the galaxy’s black hole, which then pulled at the star so that it was torn to pieces and blasted to bits and every time a clump of the star fell in towards the black hole it created a violent, energetic burst of gamma radiation and X-ray radiation. When the eruption was at its peak, the light intensity was around 100 times greater than the brightest centres of active galaxy nuclei.

The burst was first observed using the Swift Satellite and was later observed from Earth using the Nordic Optical Telescope, NOT, on the Canary Island, La Palma, among others.

"With the Nordic Optical Telescope we could identify where the burst originated from and we observed the light through different filters and in that way could describe its spectrum, i.e. light intensity as a function of wavelength. We could establish that the properties of the radiation were quite different than any other burst observed. The light itself was very broad spectrum and ranged from radio waves to infrared- and visible light to X-ray waves”, explains astrophysicist Giorgos Leloudas, Dark Cosmology Centre at the Niels Bohr Institute, University of Copenhagen and says that similar bursts have never been observed.

Rare occurrence

Because the burst is associated with the centre of the galaxy astronomers believe that it means the phenomenon is a rare mechanism connected to a supermassive black hole in the nucleus of a galaxy. And even though it is an extremely powerful event, the only reason we can observe it here on Earth is that our solar system happens to be located right in the direction where the energy beam was shot out into space.

Astronomers explain reassuringly that this type of event is so rare that even though it could happen in all galaxies – including our galaxy, the Milky Way, it will only happen a few times during a galaxy’s lifetime and the Sun is nowhere near the centre of the Milky Way, so we are safe.

Publication: "An Extremely Luminous Panchromatic Outburst from the Nucleus of a Distant Galaxy," published in Science Express.

Contact: Gertie Skaarup, Tel: + 45 3532-5320, Email: skaarup@nbi.dk

Source: Niels Bohr Institute, University of Copenhagen

Photos (1)  [ view all photos ]


Optical (left) and infrared (right) images of Sw 1644+57 obtained from ground based (top) and from the Hubble Space Telescope (bottom). The infrared light is being emitted mostly by the stellar disruption at the nucleus of the galaxy, whereas the optical light is dominated by the emission of the galaxy itself. Source: Niels Bohr Institute - University of Copenhagen

Related News:

Astronomers Discover a New Kind of Supernova 2 April 2013, 02:40
Cambridge, MA - Until now, supernovas came in two main "flavors." A core-collapse supernova is...

Supermassive Black Hole Spins Super-Fast 4 March 2013, 03:30
Cambridge, MA - Imagine a sphere more than 2 million miles across - eight times the distance...

New Black Hole Discovered In Our Galaxy 8 October 2012, 13:07
UNIVERSITY PARK, Pa. -- A tsunami of high-energy X-rays streaming toward Earth from a rare X-ray...

The Helix Nebula: Bigger in Death than Life 4 October 2012, 02:21
A dying star is refusing to go quietly into the night, as seen in this combined infrared and...

NASA's Infrared Observatory Measures Expansion of Universe 4 October 2012, 02:15
PASADENA, Calif. -- Astronomers using NASA's Spitzer Space Telescope have announced the...

MSU research sheds new light on star clusters, black holes 3 October 2012, 12:55
EAST LANSING, Mich. — Research by Michigan State University astronomers has scientists...

Solar Corona Revealed in Super-High-Definition 20 July 2012, 13:48
Cambridge, MA - Today, astronomers are releasing the highest-resolution images ever taken of...

Ghostly Gamma-ray Beams Blast from Milky Way's Center 29 May 2012, 09:45
Cambridge, MA - As galaxies go, our Milky Way is pretty quiet. Active galaxies have cores that...

IceCube Neutrino Observatory Explores Origin of Cosmic Rays 18 April 2012, 14:04
Although cosmic rays were discovered 100 years ago, their origin remains one of the most...

Astronomers Discover 'Emerald-Cut' Galaxy 22 March 2012, 04:17
An international team of astronomers has discovered a rare square galaxy with a striking...

Credits / Source:

Optical (left) and infrared (right) images of Sw 1644+57 obtained from ground based (top) and from the Hubble Space Telescope (bottom). The infrared light is being emitted mostly by the stellar disruption at the nucleus of the galaxy, whereas the optical light is dominated by the emission of the galaxy itself. Source: Niels Bohr Institute - University of Copenhagen