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Multi-wavelength view of radio galaxy Hercules A

Date:
November 29, 2012
Source:
Space Telescope Science Institute (STScI)
Summary:
Spectacular jets are powered by the gravitational energy of a supermassive black hole in the core of the elliptical galaxy Hercules A.
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VLA RADIO IMAGE OF HERCULES A (3C 348). This VLA radio composite image shows the active galaxy 3C 348, also known as Hercules A. The VLA data, which record frequencies from 4-9 GHz were taken in 2010-2011.
Credit: R. Perley and W. Cotton (NRAO/AUI/NSF)

Spectacular jets powered by the gravitational energy of a supermassive black hole in the core of the elliptical galaxy Hercules A illustrate the combined imaging power of two of astronomy's cutting-edge tools, the Hubble Space Telescope's Wide Field Camera 3, and the recently upgraded Karl G. Jansky Very Large Array (VLA) radio telescope in New Mexico.

Some two billion light-years away, the yellowish elliptical galaxy in the center of the image appears quite ordinary as seen by Hubble in visible wavelengths of light. The galaxy is roughly 1,000 times more massive than our Milky Way and harbors a 2.5-billion-solar-mass central black hole that is 1,000 times more massive than the black hole in the Milky Way. But the innocuous-looking galaxy, also known as 3C 348, has long been known as the brightest radio-emitting object in the constellation Hercules. Emitting nearly a billion times more power in radio wavelengths than our Sun, the galaxy is one of the brightest extragalactic radio sources in the entire sky.

The VLA radio data reveal enormous, optically invisible jets that, at one-and-a-half million light-years long, dwarf the visible galaxy from which they emerge. The jets are very-high-energy plasma beams, subatomic particles and magnetic fields shot at nearly the speed of light from the vicinity of the black hole. The outer portions of both jets show unusual ring-like structures suggesting a history of multiple outbursts from the supermassive black hole at the center of the galaxy.

The innermost parts of the jets are not visible because of the extreme velocity of the material; relativistic effects confine all of the light to a narrow cone aligned to the jets, so the light does not reach us. Far from the galaxy, the jets become unstable and break up into rings and wisps.

The entire radio source is surrounded by a very hot, X-ray-emitting cloud of gas, not seen in this optical-radio composite.


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The above post is reprinted from materials provided by Space Telescope Science Institute (STScI). Note: Materials may be edited for content and length.


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Space Telescope Science Institute (STScI). "Multi-wavelength view of radio galaxy Hercules A." ScienceDaily. ScienceDaily, 29 November 2012. <www.sciencedaily.com/releases/2012/11/121129092958.htm>.
Space Telescope Science Institute (STScI). (2012, November 29). Multi-wavelength view of radio galaxy Hercules A. ScienceDaily. Retrieved September 3, 2015 from www.sciencedaily.com/releases/2012/11/121129092958.htm
Space Telescope Science Institute (STScI). "Multi-wavelength view of radio galaxy Hercules A." ScienceDaily. www.sciencedaily.com/releases/2012/11/121129092958.htm (accessed September 3, 2015).

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