See a black hole's blast
Posted: Thursday, January 29, 2009 9:04 AM by Alan Boyle
ESO
This composite image of Centaurus A shows lobes and jets emanating from the
galaxy's central black hole. The image combines data from the APEX radio
telescope, the Chandra X-ray Observatory and the MPG/ESO 2.2-meter telescope.
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Radio observations are filling out an impressive picture of huge jets blasting out from a galactic black hole. The latest findings support the view that Centaurus A is a giant particle accelerator, powered by the active galaxy's matter-sucking monster.
Centaurus A is a giant elliptical galaxy that's in the process of merging with a companion spiral galaxy, about 13 million light-years from Earth in the southern constellation Centaurus. Like our own Milky Way galaxy, Centaurus A has a supermassive black hole at its center, with a mass equal to 100 million suns. (Our galaxy's supermassive black hole is wimpy in comparison, weighing only as much as 4 million suns.)
All that crashing, smashing and swirling around Centaurus A sparks intense star formation, making it one of the most spectacular objects in the sky - particularly when it comes to radio and X-ray emissions.
The latest image from the European Southern Observatory combines a true-color background view from the Wide Field Imager on the ESO's 2.2-meter telescope at La Silla in Chile with an X-ray view (in blue) from the Chandra X-ray Observatory and the radio view from the Large APEX Bolometer Camera. That camera, also known as LABOCA, is mounted on the international APEX submillimeter-wave radio telescope in Chile.
LABOCA's submillimeter view plainly shows the heat glow from the galaxy's dusty main disk and the bright radio emission from the galaxy's center. It also shows the radio emissions from jets of accelerated particles shooting north and south from the center.
As detailed in an image advisory issued Wednesday, such emissions occur when fast-moving electrons spiral around the lines of a magnetic field. The electrons emanating from Centaurus A are traveling at half the speed of light, and then slamming into the surrounding gas to create a shock wave. That's what's causing the bluish X-ray emissions that are most prominent in the lobe the lower right of the galaxy.
ESA / NASA / AVO Project / Paolo Padovani |
This artist's conception of a galactic black hole is
similar to the ESO's picture of the real thing.
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Those jets and lobes are the coolest features of the image, and they don't always show up in pictures of Centaurus A. (Here's an example). LABOCA's sensitivity to submillimeter wavelengths is well-suited for charting the radio emissions from the outflow. That's one of the subjects covered in a research paper published by the journal Astronomy and Astrophysics.
The team behind the LABOCA observations was led by Axel Weiss of Germany's Max Planck Institute for Radio Astronomy. Other members of the Max Planck team include Attila Kovacs, Rolf Güsten, Karl M. Menten, Frederic Schuller, Giorgio Siringo and Ernst Kreysa.
We've had a veritable banquet of black hole tales over the past month - so take advantage of this all-you-can-eat smorgasbord:
