LETGS/XTE J1118+480
Credit: NASA/CfA/J. McClintock, M. Garcia

X Marks the Hole

Astronomers have a limited number of tools available to explore the Universe. One of the most powerful is spectrometry, in which light from an astronomical source is broken down into its component wavelengths. Until recently X-ray astronomers were at a disadvantage, since X-ray observatories were only able to generate crude spectra of most sources in the sky. However, the Chandra X-ray observatory has changed all that. The Chandra observatory uses diffraction gratings to spread out X-ray starlight so astronomers can precisely determine the temperature and chemical composition and other properties of the X-ray source. The image above shows an observation of the suspected black hole system known as XTE J1118+480 made by the Low Energy Transmission Grating (LETG). The source is at the center of the field at the intersection of the bright rays. The X-ray spectrum of the source can be seen as the bright diagonal line on either side of the source. The "spokes" and the fainter diagonal lines are artifacts due to the structure that supports the LETG grating elements

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Each week the HEASARC brings you new, exciting and beautiful images from X-ray and Gamma ray astronomy. Check back each week and be sure to check out the HEAPOW archive!

Page Author: Dr. Michael F. Corcoran
Last modified June 12, 2001