(coming soon, to a space agency near you.)
A lot of my research has to do with searching for black holes. Idealy the searches will use an instrument (lovingly) called LISA. LISA looks like this.
A theorist-assembled miniature version of LISA looks like this.
It's about ten billion times smaller and a billion times cheaper than the real deal. Unfortunately, being made by theorists, this model has only imaginary functions. It has real lasers though, and we lined them up real good.
It might be possible to do the specific black hole searches that I'm working on with detectors here on earth like the advanced version of the American LIGO detectors. This movie shows the kind of real estate you would need if you wanted to move the LIGO detector in Hanford Washington to Los Angeles.
I'm interested in using these instruments to listen for signals radiated by a special class of pairs of black holes, extreme mass-ratio inspirals (EMRIs). EMRIs look like this:
The image above sketches the orbit of the smaller object as a kind of eliptical sort of thing. Orbits that are close to black holes are actually a lot more crazy looking. Here's an example of what a real orbit would look like near the black hole in the center of our galaxy (the hole is lovingly called SgrA*, which is obviously pronouned Sagittarius-eh-star).
If you're curious about the details, this example orbit has an eccentricity of 1/2, an inclination of 45 degrees, and a semilatus-rectum of 4.5. Oh, and I cheated by supposing that SgrA* is spinning (about the z-axis) at 90% of the maximum allowed rate. Observations have yet to tell much about how fast that hole is spinning, but its mass has been measured to be 3.6-3.7 million times that of our sun. Check out the sites for the Garching group or the UCLA group to find out what's actually known about the black hole in the middle of our galaxy.
That last example is typical of the sort of things that LISA could observe. The ground based detectors like advanced versions of LIGO (see the official page for details of what that detector will really be like) would look for systems with a big black hole that is much less massive, falling somewhere in these regions shaded in bright red (extremely advanced detectors) to dark red (less advanced, but still fancy)
It's believed that orbits around these kinds of black holes won't be very eccentric. They'll look like this:
Again, if you're interesed in the details of this simulation, here the big black hole's mass is only 500 times that of the sun, it's spinning at 90% of the maximal rate, the orbit has eccectricity of 0.005, semilatus-rectum of 4.5, and inclination of 45 degrees.
As the smaller object moves around the big black hole, it radiates gravitational waves. It's these waves that I study, and that are hoped to be observable in the near future. This process is described in a bit better detail at a site run by the Caltech-Cornell project black-holes.org. There, you can also find examples of what the radition will sound like. This is one of their examples:
The frequency, or pitch, in that audio example is only right if the system is the sort that LIGO can look for. The signals that LISA will look for happen at much lower frequencies. Here's a movie of what those signals are like:
This is the spectrum of radiation produced when the captured object moves along a specific inspiraling orbit simulated by Jon Gair. The spectrum itself was made by me, using black hole perturbation theory. For the system that would produce the spectrum shown here, the big object is a one million solar mass black hole, spinning at 90% of the maximal value. The captured object is a ten solar mass black hole, with negligible spin.
This movie shows the spectral lines carrying 99% of the radiated power, at intervals of roughly 12 hours, over the last three years of inspiral. If you watch the movie with sound, keep in mind that the sound you're hearing has an artificially high pitch. This was done so that the sound will actually be something that you can hear, and to squeeze something that should last about 3 years into just 60 seconds. Astronomers do the same kind of thing when they pick colors for displaying radio images, X-ray images, etc.
The total "cost" for this particular calculation was about 1.5 CPU-years on a 3.2 GHz Pentium 4 Xeon processor. It helped to have more than one such machine. This is the cluster I used. The supercomputers used in this investigation were provided by funding from the JPL Office of the Chief Information Officer.
I've since made another batch of animations which show the motion and sound that go along with the last movie above. I made those movies with computers provided by The Max Planck/Albert Einstein Institute in Potsdam, and by the German space agency.