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X-Ray Crab

Published on Nov 7, 2008 at 5:13 pm. 1 Comment.
Filed under astronomy, nebula, neutron stars.

Messier 1, the Crab Nebula, is a famous supernova remnant in Taurus. It was left behind by the supernova visible from Earth in 1054. The Crab Nebula is about 6000 light years away. The image above is a composite make from three different instruments. The green and dark blue images were made using the Hubble Space Telescope, the light blue and purple were from the Chandra X-Ray Telescope, and the red is and infrared image from the Spitzer Space Telescope (all three telescopes are orbital space telescopes). None of these are true colors, of course, since the non-visual infrared and X-ray images have been displayed as visual colors, and the Hubble image was mapped to other colors to be able to show it is as different from the others. Still, this is a very nice image, and it gives some perspective to the complexity of the Crab Nebula. However, sometimes too much information allows subtle details to be lost. The following image is only the X-ray image from the Chandra telescope. As with many of the images that I post, you can click on them to see a larger size image.

This is a slightly enlarged view of the part of the top image that is shown in light blue and purple. Don’t worry about the colors. This is an X-ray image. We use computer generated colors that tell us information about what we are seeing. In this image, the different colors correspond to different intensities of X-rays. Since these X-rays do not penetrate through Earth’s atmosphere, they need to be observed from space. That is what the Chandra does. The X-rays are given off by the extremely high energy particles streaming away from the neutron star at the heart of the nebula. When the progenitor star died in a massive supernova, most of the star was blasted out into space to form the nebula; however, the core of the star collapsed to form a neutron star. That neutron star betrays its presence by the pulses that it emits as it rapidly spins.

This image shows the jets of material streaming away from the poles of the neutron star. These jets are composed of particles of matter and antimatter from near the neutron star’s surface, largely in the form of electrons and positrons (anti-electrons). These jets extend for several light years, with the particles moving at an appreciable percentage of the speed of light. Particles also move outward from the equator of the neutron star, perpendicular to the magnetic field, but not nearly as quickly. The inner ring around the neutron star is perhaps where these particles are running into the surrounding nebular material and slowing down. The dark voids on the left and right of the image are described as possibly due to interactions of the nebula material with the remnants of the magnetic field from the original progenitor star. You can read a bit more in a recent press release.

-Astroprof

Image Credit: NASA/CXC/SAO/F.Seward