EDWARD'S LECTURE NOTES:
More notes at http://tanguay.info/learntracker
C O U R S E 
Analyzing the Universe
Terry Matilsky, Rutgers University
https://www.coursera.org/course/analyze
C O U R S E   L E C T U R E 
Capturing Images of X-Ray Sources from Space
Notes taken on January 12, 2015 by Edward Tanguay
visible light can be bounced of a curved mirror and directed to a focal point
x-ray light, however, will be absorbed by the mirror
will not bounce back to the focal point
X-ray photons penetrate into the mirror in much the same way that bullets slam into a wall
likewise, just as bullets ricochet when they hit a wall at a grazing angle, so too will X-rays ricochet off mirrors
therefore X-ray telescopes must be constructed very different from optical telescopes
mirrors have to be precisely shaped and aligned nearly parallel to incoming X-rays
they look more like barrels than the familiar dish shape of optical telescopes
x-ray telescope
designed to observe remote objects in the X-ray spectrum
the Earth's atmosphere absorbs X-rays, X-ray observatories
must therefore be mounted on high altitude rockets or artificial satellites in order to get above the Earth's atmosphere
mirrors, detectors, and electronics that convey the information back to Earth must be able to
withstand the rigors of a rocket launch
operate in the hostile environment of space
NASA's Chandra X-ray Observatory
most important X-ray astronomy mission to date
launched on July 23, 1999
four sets of nested mirrors
the mirror surface was coated with iridium, a material more reflective than gold
Sco X-1 (Scorpius X-1)
roughly 9000 light years away in the constellation Scorpius
aside from the Sun, it is the strongest apparent source of X-rays in the sky
is associated with an optically visible star, V818 Scorpii