Everything Science Forum

Most Distant Black Hole Discovered
http://news.yahoo.com/s/space/20070607/sc_space/mostdistantblackholediscovered (http://news.yahoo.com/s/space/20070607/sc_space/mostdistantblackholediscovered)

The most distant black hole ever found is nearly 13 billion light-years from Earth, astronomers announced today.

The Canada-France-Hawaii Telescope spotted the bright burst of light the black hole created as it sucked up nearby gas, heating it and causing it to glow very brightly in what's known as a quasar.

The distance to the quasar, which sits in the constellation Pisces, was determined by measuring the amount of redshift in the lines of the quasar's spectrum, or prism of light. Because light is "redshifted" to longer wavelengths as an object moves away from an observer, the higher the redshift, the further away the object is-and this quasar had quite a large redshift.

"As soon as I saw the spectrum with its booming emission line, I knew this one was a long way away," said team member Chris Willott of the University of Ottawa.

Because the Big Bang is believed to have occurred around 13.7 billion years ago, astronomers are seeing the quasar as it appeared a mere 1 billion years after the Big Bang, which gives them a unique view into universe's past.

I dare say, of all the gifts the gods have blessed us with, none are more beautiful than the galaxies they have seeded for us to admire and explore.

Okay, I'm getting this right?

Quasars are associated with galaxies, being the geysers of black holes. The further away we find galaxies, the less time they have to be born and raised after the Big Bang.

If that's right, then a galaxy can form in less than a billion years? Wikipedia gives an estimate of probably more than one hundred billion galaxies. This means there was an awful lot of activity at the start?

Would an accelerating universe mean even more activity to come?

All good questions!  The more we learn, the more we know we don't understand.

Certainly if this quasar is at 13 billion years, then we are looking back 13 billion years.  This object may not exist anymore - in fact many stars beyond a few billion light year would presumably be reaching the end of their lives or beyond the lifetime.  Objects out at 10-13 billion years, may no longer exist, but we will not know because that light won't fade for billions of years.  Anyway . . .

Active galaxies are galaxies which have a small core of emission embedded in an otherwise typical galaxy. This core may be highly variable and very bright compared to the rest of the galaxy. Models of active galaxies concentrate on the possibility of a supermassive black hole which lies at the center of the galaxy. The dense central galaxy provides material which accretes onto the black hole releasing a large amount of gravitational energy. Part of the energy in this hot plasma is emitted as x-rays and gamma-rays.

For "normal" galaxies, we can think of the total energy they emit as the sum of the emission from each of the stars found in the galaxy. For the "active" galaxies, this is not true. There is a great deal more emitted energy than there should be... and this excess energy is found in the infrared, radio, UV, and X-ray regions of the electromagnetic spectrum. The energy emitted by an active galaxy (or AGN) is anything but "normal". So what is happening in these galaxies to produce such an energetic output?

There are several types of active galaxies: Seyferts, quasars, and blazars. Most scientists believe that, even though these types look very different to us, they are really all the same thing viewed from different directions! Quasars are active galaxies which are all very, very, very far away from us. Some of the quasars we have seen so far are 12 billion light-years away! . . . .

http://imagine.gsfc.nasa.gov/docs/science/know_l1/active_galaxies.html