Friday, June 26, 2009

Supernova Remnant W49B

(Credit: Caltech/SSC/J.Rho and T. Jarrett)

This is from a couple of years ago but I felt like posting an astrophoto today, so this is what you get. The image above shows a supernova remnant known as W49B.

It is a composite image taken by the orbiting Chandra X-ray Observatory and the 200-inch Hale Telescope at Palomar Observatory. It is a false-color combination of X-ray (blue) and near-infrared (red and green) light. The image is 5.7 arcmin on each side.

It is images such as this one that really highlight how ground-based and orbiting telescopes work hand in hand for astronomers as they attempt to unravel the secrets of the universe.

Here's what the Chandra website has to say about the image:

supernova remnant W49B reveals a barrel-shaped nebula consisting of bright infrared rings around a glowing bar of intense X-radiation along the axis.The X-rays in the bar are produced by 15 million degree Celsius gas that is rich in iron and nickel ions. At the ends of the barrel, the X-ray emission flares out to make a hot cap. The X-ray cap is surrounded by a flattened cloud of hydrogen molecules detected in the infrared. These features indicate that jets of hot gas produced in the supernova have encountered a large, dense cloud of gas and dust.

The following sequence of events has been suggested to account for the X-ray and infrared data: A massive star formed from a dense cloud of dust and gas, shone brightly for a few million years while spinning off rings of gas and pushing them away to form a nearly empty cavity around the star. The star then exhausted its nuclear fuel and its core collapsed to form a black hole. Much of the gas around the black hole was pulled into it, but some, including material rich in iron and nickel was flung away in oppositely directed jets of gas traveling near the speed of light. When the jet hit the dense cloud surrounding the star, it flared out and drove a shock wave into the cloud.

An observer aligned with one these jets would have seen a gamma-ray burst, a blinding flash in which the concentrated power equals that of ten quadrillion Suns for a minute or so. The view perpendicular to the jets would be a less astonishing, although nonetheless spectacular supernova explosion. For W49B, the jet is tilted out of the plane of the sky by about 20 degrees, but the remains of the jet are visible as a hot X-ray emitting bar of gas.

W49B is about 35 thousand light years away, whereas the nearest known gamma-ray burst to Earth is several million light years away - most are billions of light years distant. If confirmed, the discovery of a relatively nearby remnant of a gamma-ray burst would give scientists an excellent opportunity to study the aftermath of one of nature's most violent explosions.
The infrared data was observed with the 200-inch Hale Telescope's Wide-field Infrared Camera (WIRC). The individual frames, in very high resolution) from Palomar and Chandra can be found here.

1 comment:

Mr Squid said...

What a pretty picture. It is too bad that our eyes do not see the cosmos like that.