Rotating Question Curious About Astronomy? Ask an Astronomer

How powerful are quasars?

As quasars are the most distant objects in the night sky, they are therefore subject to the greatest speed of recession. Is it possible, therefore, that the weird measurements we obtain for their energy output and size could be a result of relativistic effects rather than being intrinsic to their natures?

The measurements which are reported for quasars are already corrected for redshift and other relativistic effects. An assumption which is occasionally used the calculations of total energy output, however, is that they emit all their radiation "isotrpically." That means we assume the same amount of energy is radiated in all directions. Quasars, however, are probably the result of high-energy jets from supermassive black holes which happen to be pointed directly at us. If we were to view the same object from a different angle, we would not observe the same high energies. Clearly, such jets are not isotropic. Therefore, isotropic energy estimates for quasars are probably vast overestimates. Astronomers understand this and try not to compare such estimates to other phenomena. Eiter way, though, quasars are some of the most energetic objects in the sky.

January 1999, Dave Kornreich (more by Dave Kornreich) (Like this Answer)

Still Curious?

Get More 'Curious?' with Our New PODCAST:

Related questions:

More questions about Black Holes and Quasars: Previous | Next

How to ask a question:

If you have a follow-up question concerning the above subject, submit it here. If you have a question about another area of astronomy, find the topic you're interested in from the archive on our site menu, or go here for help.

Table 'curious.Referrers' doesn't existTable 'curious.Referrers' doesn't exist

This page has been accessed 23097 times since September 29, 2002.
Last modified: October 25, 2002 4:35:14 PM

Legal questions? See our copyright, disclaimer and privacy policy.
Ask an Astronomer is hosted by the Astronomy Department at Cornell University and is produced with PHP and MySQL.

Warning: Your browser is misbehaving! This page might look ugly. (Details)