Measuring Radiation From Matter Entering Black Hole Home Search Measuring Radiation From Matter Entering Black Hole NASA's Chandra X-ray Observatory has examined the stormy environs of a giant black hole in the active galaxy NGC 3783 and measured the dramatic effects of intense radiation produced by matter before it plunges into the black hole. A team of researchers used the High Energy Transmission Grating in combination with the CCD X-ray camera aboard Chandra to study the properties of the wind. Computers translate this display into a jagged-line plot that resembles an electrocardiogram.
Specific elements reveal their presence by sharp absorption dips in the plot.
By examining the widths and locations of these dips, the researchers can use the same principle used by a radar gun to measure velocities in the extreme environment of the galaxy's core. It reveals that the wind contains oxygen, neon, magnesium, silicon, sulfur, argon and iron. An analysis of the wind by team member Professor Hagai Netzer of Tel-Aviv University in Israel showed that the wind almost completely surrounds the black hole. The event horizon of the central black hole in NGC 3783 has a diameter about a hundred times that of the sun, but it produces more radiation than a billion suns as gas is sucked into the black hole at nearly the speed of light. A portion of this powerful radiation is absorbed by gas that surrounds the black hole.