Education Activities To Accompany Chandra Data Analysis Software Cas A
Activity 1: Pixels, Pixels, Everywhere
1. To see the astonishing detail in this picture, play with the contrast/bias control by right clicking anywhere in the image and dragging the mouse around (while still holding the button down). This is fun! Try to obtain the most detail possible in the picture.
2. Select the "he" color map. Go to Color-->contrast/bias, and set the pointers at contrast 6.7 and bias 0.06. This viewpoint is extremely instructive. First, you see a rotated square which shows you the extent of the satellite's field of view. Also, you see a very bright (almost white) lumpy, but somewhat circular region surrounding the central point-like object. Outside the lumpy region, we see a fainter, more wispy region. What is all this telling us?
We have pieced together the following story...
About 300 years ago, the star that is now the central object exploded. Remarkably, it was not seen by anyone, apparently, even though these explosions, as we have seen, are usually large enough so that the radiation can provide enough light for reading at midnight. How, then, do we know when it happened? Optical data shows material (via the Doppler effect) streaming outward from the object at thousands of kilometers/sec. If we run this expansion backwards, the material would get back to the center in about 350 years. Thus, the object should have been visible around 1650 AD.
