But why is the Corona ejected?
Space news (November 02, 2015) –
Bizarre and mysterious stellar objects, studying black holes keeps astronomers up all night. One of the more puzzling mysteries of these unique objects are gigantic flares of X-rays (relativistic jets) detected erupting from disks of hot, glowing dust surrounding them. X-ray flares astronomers are presently studying in order to better understand these enigmatic, yet strangely attractive stellar objects.
Astronomers observing supermassive black holes using NASA’s Swift spacecraft and Nuclear Spectroscopic Telescope Array (NuSTAR) recently caught one in the middle of a gigantic X-ray flare. After analysis, they discovered this particular flare appeared to be a result of the Corona surrounding the supermassive black hole – region of highly energetic particles – being launched into space. A result making scientists and astronomers rethink their theories on how relativistic jets are created and sustained.
This result suggests to scientists that supermassive black holes emit X-ray flares when highly energized particles (Coronas) are launched away from the black hole. In this particular case, X-ray flares traveling at 20 percent of the speed of light, and directly pointing toward Earth. The ejection of the Corona caused the X-ray light emitted to brighten a little in an effect called relativistic Doppler boosting. This slightly brighter X-ray light has a different spectrum due to the motion of the Corona, which helped astronomers detect this unusual phenomenon leaving the disk of dust and gas surrounding this supermassive black hole.
“This is the first time we have been able to link the launching of the Corona to a flare,” said Dan Wilkins of Saint Mary’s University in Halifax, Canada, lead author of a new paper on the results appearing in the Monthly Notices of the Royal Astronomical Society. “This will help us understand how supermassive black holes power some of the brightest objects in the universe.“
Astronomers currently propose two different scenarios for the source of coronas surrounding supermassive black holes. The “lamppost” scenario indicates coronas are analogous to light bulbs sitting above and below the supermassive black hole along its axis of rotation. This idea proposes coronas surrounding supermassive black holes are spread randomly as a large cloud or a “sandwich” that envelopes the disk of dust and material surrounding the black hole. Some astronomers think coronas surrounding supermassive black holes could alternate between both the lamppost and sandwich configurations.
The latest data seems to lean toward the “lamppost” scenario and gives us clues to how the coronas surrounding black holes move. More observations are needed to ascertain additional facts concerning this unusual phenomenon and how massive X-ray flares and gamma rays emitted by supermassive black holes are created.
“Something very strange happened in 2007, when Mrk 335 faded by a factor of 30. What we have found is that it continues to erupt in flares but has not reached the brightness levels and stability seen before,” said Luigi Gallo, the principal investigator for the project at Saint Mary’s University. Another co-author, Dirk Grupe of Morehead State University in Kentucky, has been using Swift to regularly monitor the black hole since 2007.
“The Corona gathered inward at first and then launched upwards like a jet,” said Wilkins. “We still don’t know how jets in black holes form, but it’s an exciting possibility that this black hole’s Corona was beginning to form the base of a jet before it collapsed.”
“The nature of the energetic source of X-rays we call the Corona is mysterious, but now with the ability to see dramatic changes like this we are getting clues about its size and structure,” said Fiona Harrison, the principal investigator of NuSTAR at the California Institute of Technology in Pasadena, who was not affiliated with the study.
Astronomers will now continue their study of supermassive black holes in the cosmos in order to remove the veil of mystery surrounding the X-ray flares they emit and other bizarre mysteries surrounding these enigmatic stellar objects. In particular, they would love to discover the reasons for the ejection of Coronas surrounding black holes.
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Discover the Swift spacecraft here.
Take the voyage of NASA’s NuSTAR spacecraft here.
Take part in NASA’s mission to the stars here.
Learn more about climatic collisions between galaxy clusters.