Thursday, July 24, 2008

Black Hole Thursdays.

Astronomers have for the first time developed a technique to view rapidly spinning disks of gas found near black holes.

Their observations allowed them to confirm the that the electromagnetic spectra of these accretion disks match what astronomers have long predicted, giving a boost of hard evidence to current quasar formation theory.

The team of researchers gazed into the night on Mauna Kea in Hawaii, looking through the United Kingdom Infrared Telescope. They were able to measure the spectrum of the accretion disk by getting rid of extra, interfering light, using a polarizing filter attached to the telescope.

Why exactly are polarized filters so special? Well, they aren't. It is the way that accretion disks emit light that lets the filter do its job. Accretion disks emit non-polarized light that doesn't care how its electrical field is aligned, known as direct light. But a small amount of accretion disk light reflects off gas very close to the black hole- this light is polarized. By only analyzing polarized light, researchers are able to ignore all the direct-light emitting irrelevant stuff, like dust particles and ionized gas.

Quasars are extremely bright, distant objects that also emit frenzied, massive amounts of energy. They are powerful, but until now no one has been able show that accretion disks falling toward black holes, particular near the horizon or black hole boundary, is the source of much that power.

1 comment:

  1. The article Low Mass Black Holes Still Grow Today explains how smaller black holes grow faster than larger black holes.

    The math behind black hole growth is currently somewhat of a mystery. One recently proposed possibility is that reverse Hawking Radiation might feed black holes, black holes might grow from consuming virtual particles. If the universe is filled with as much dark energy as some physicists speculate, then the rapid growth of black holes might be better explained.

    If reverse Hawking Radiation might actually cause black holes to grow, then we definitely would not want to create micro black holes in colliders.