Magnetic Fields Detected At Milky Way’s Giant Black Hole

Posted: Dec 4 2015, 7:26am CST | by , in News | Latest Science News


Magnetic Fields Detected at Milky Way’s Giant Black Hole
n this artist's conception, the black hole at the center of our galaxy is surrounded by a hot disk of accreting material. Blue lines trace magnetic fields. The Event Horizon Telescope has measured those magnetic fields for the first time. Credit: M. Weiss/CfA
  • Event Horizon Telescope probes magnetic field around Milky Way’s giant Black Hole!

The magnetic fields which are a point of no return around Sagittarius A* have been detected.

Black holes are cosmic engines situated at the centers of galaxies. The black holes convert energy from in falling matter into intense radiation. The combined radiation can produce light to outshine all the surrounding stars.

A spinning black hole can generate strong jets which have the potential to even shape entire galaxies. Astronomers believe black holes are powered by strong magnetic fields. One such giant black hole exits at the heart of the Milky Way galaxy. The supermassive black hole at the center of the Milky Way is called Sagittarius A*.

For the first time scientists have been successful in detecting magnetic fields around the black hole. The magnetic field was found outside the event horizon of Sagittarius A*.The event horizon is known as the ‘point of no return’.

Beyond the black hole point nothing, not even light, can escape. The black hole Sagittarius A* lies at a distance of about 25,000 light-years from Earth. The black of the Milky Way is about 4 million times more massive than the sun in size. The black hole is also known as Sgr A*. 

The results were posted today in the 4th of December issue of the journal Science. Michael Johnson of the Harvard-Smithsonian Center for Astrophysics is the lead author. According to Johnson understanding magnetic fields is critical aspect. Johnson also claimed no one had been able to resolve the magnetic fields around event horizon before them. 

Shep Doeleman is the assistant director of MIT's Haystack Observatory. Doeleman was also a principal investigator on the search for the magnetic fields. According to Doeleman the magnetic fields were theoretically predicted to exist around Sgr A*.

However there was no proof of their existence before. The data unearthed in the research backs up decades of theoretical work on black holes. The theoretical work was previously only based on assumptions and observations, now there is solid proof. 

The magnetic field around Sgr A* was found by using the giant Event Horizon Telescope (EHT). The EHT is a global network of radio telescopes linked together. The radio telescopes function as one giant telescope equal to the size of the Earth.

The EHT has a capability of magnifying features as small as 15 micro-arcseconds. Since black holes are the most compact object in the universe such resolution power is necessary.

EHT observed Sgr A* at a wavelength of 1.3 mm. The team behind EHT measured how light is linearly polarized around Sgr A*. The polarized light around Sgr A* was emitted by electrons spiralling around the magnetic field lines. The polarized light traced the structure of the magnetic field. 

The magnetic field was found to be in an ordered and disordered direction in some regions. Some regions were disorderly, with jumbled loops and whorls. The direction of the magnetic field even resembled intertwined spaghetti. While other regions showed organized patterns. It was speculated the organized regions could be where the jets are generated.

The magnetic fields were also found to fluctuate on short time scales of only 15 minutes. The magnetic field of the black hole was found to be a more dynamic place than expected. Johnson stated the magnetic field was like dancing all over the place. 

The results of this study appear in the Dec. 4th issue of the journal Science. The findings have brought astronomers one step closer to solving the most central puzzle in astronomy. The phenomenon of why Black Holes are so bright?

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<a href="/latest_stories/all/all/20" rel="author">Sumayah Aamir</a>
Sumayah Aamir (Google+) has deep experience in analyzing the latest trends.




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