November 29, 2012
Elliptical Galaxy Shows Off For Hubble
[ Watch the Video: Hercules A Zoom Sequence ]
Lee Rannals for redOrbit.com - Your Universe Online
A new Hubble Space Telescope image released today shows off a multi-wavelength view of radio galaxy Hercules A.
The image was produced through a collaboration of the Hubble Space Telescope's Wide Field Camera 3, and the upgraded Karl G. Jansky Very Large Array (VLA) radio telescope in New Mexico.
The yellowish elliptical galaxy seen in the image is about 1,000 times more massive than the Milky Way, and it holds a 2.5-billion-solar-mass central black hole that is 1,000 times more massive than Milky Way's black hole.
The galaxy has been known as the brightest radio-emitting object in the constellation Hercules. It emits nearly a billion times more power in radio wavelengths than our Sun, and is one of the brightest extragalactic radio sources in the sky.
VLA's radio data helped to reveal enormous jets at one-and-a-half-million light-years wide. 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 jets are not visible in the image because of the extreme velocity of the material, causing relativistic effects that beam the light away from us. Jets from the galaxy become unstable and break up into the rings and wisps.
Hubble's view of the field also shows a companion elliptical galaxy close to the center of the optical-radio source, which may be merging with the central galaxy.
Several other elliptical and spiral galaxies that are visible in the Hubble data may be members of a cluster of galaxies, but Hercules A is the brightest, most massive galaxy in the cluster.