Feeding Black Holes

Illumination of the Invisible

Jul 30, 2007

Like the footsteps in the snow of an invisible man, feeding black holes are easily seen

The Great Whites of the Universe, Black Holes affects everything within their gravitational field. Carcharadon Carchariusis not only an apex predator of the seas but also an elusive monster that scientist have a difficult time spotting. According to Dr. Alice Christie of Arizona State University “these sharks are hard to study because they are hard to find….” So too the Black Hole, but just as the blood trail will point to a great white in the area so will the trail of stellar debris from a feeding black hole point to its location in the cosmos.

Size

Black holes do not go around the universe "sucking" in everything in its path; however, any matter that falls within the gravitational field of the black hole will be affected, including being consumed. In Black Holes Space Time Distortion we understood that black holes come in different sizes. Depending on the mass of the star’s core, we can determine the gravitational forces the remains will create. There is a direct correlation between the mass of the hole and the gravitation arm (the reach) the hole will have.

Spotting

We have already determined that light can not escape from just inside the photon sphere and as a result it is impossible to spot one of these monsters. However, when an object is affected by the gravitational forces the object’s changed trajectory can be observed. Black Holes can be as benign as creating a wobble on a planet to as destructive as consuming whole solar systems.

There are two basic ways of spotting these holes in space. First are visual observations on surrounding objects and second is from exceedingly large X-ray emissions coming from an area in space. This article will concentrate on the former method of detection.

Feeding

As objects fall into the gravitational field of a black hole several things occur. The orbital trajectory of the object changes and if the object gets too close it starts a decaying orbit around the core remnant. The closer the object gets (let’s make it a star) the stronger the gravitational forces are and the star starts to tear apart. Matter is ripped off the orbiting star until the very star itself is torn to dust and gas. This matter continues to orbit the core at an ever decreasing radius with increasing speed. The matter (mainly super heated gas) starts to both heat up and pile up around the event horizon in an area called the Accretion Disk. Once all the matter is reduced the accretion disk starts to diminish until all the matter has fallen past the event horizon and into the singularity. Much as water falling down a drain, this orbital decay and the birth of the accretion disk can be visually observed for as long as the matter is white hot and in the disk.

Another more readily method of observation is that seen in the “bi-polar jets”; symmetrically opposite each other and at 90 degree angles to the accretion disk. It is believed that the accretion disk produces tangled fields of magnetic energy that if sufficiently large, will create a magnetic dynamo and “lift” the jets away from the gravitational force of the core. These jets, while a relatively small percentage of the matter in the accretion disk, burn white hot and propel matter millions of miles into space. The jets produce the tell tale signal that a Black Hole is there!

The copyright of the article Feeding Black Holes in Deep Space Astronomy is owned by Frank W. Hardy. Permission to republish Feeding Black Holes in print or online must be granted by the author in writing.