NASA | JPL-Caltech | Swift | NuSTAR | 2015 Oct 27
[img3="This diagram shows how a shifting feature, called a corona, can createThe baffling and strange behaviors of black holes have become somewhat less mysterious recently, with new observations from NASA's Explorer missions Swift and the Nuclear Spectroscopic Telescope Array, or NuSTAR. The two space telescopes caught a supermassive black hole in the midst of a giant eruption of X-ray light, helping astronomers address an ongoing puzzle: How do supermassive black holes flare?
a flare of X-rays around a black hole. (Credit: NASA/JPL-Caltech)"]http://www.jpl.nasa.gov/images/nustar/2 ... 051-16.jpg[/img3][hr][/hr]
The results suggest that supermassive black holes send out beams of X-rays when their surrounding coronas -- sources of extremely energetic particles -- shoot, or launch, away from the black holes. ...
Supermassive black holes don't give off any light themselves, but they are often encircled by disks of hot, glowing material. The gravity of a black hole pulls swirling gas into it, heating this material and causing it to shine with different types of light. Another source of radiation near a black hole is the corona. Coronas are made up of highly energetic particles that generate X-ray light, but details about their appearance, and how they form, are unclear.
Astronomers think coronas have one of two likely configurations. The "lamppost" model says they are compact sources of light, similar to light bulbs, that sit above and below the black hole, along its rotation axis. The other model proposes that the coronas are spread out more diffusely, either as a larger cloud around the black hole, or as a "sandwich" that envelops the surrounding disk of material like slices of bread. In fact, it's possible that coronas switch between both the lamppost and sandwich configurations.
The new data support the "lamppost" model -- and demonstrate, in the finest detail yet, how the light-bulb-like coronas move. The observations began when Swift, which monitors the sky for cosmic outbursts of X-rays and gamma rays, caught a large flare coming from the supermassive black hole called Markarian 335, or Mrk 335, located 324 million light-years away in the direction of the constellation Pegasus. This supermassive black hole, which sits at the center of a galaxy, was once one of the brightest X-ray sources in the sky. ...
Flaring from the supermassive black hole in Mrk 335 studied with Swift and NuSTAR - D.R. Wilkins et al
- arXiv.org > astro-ph > arXiv:1510.07656 > 26 Oct 2015
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