Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

HLX-1 brightest ultra-luminous X-ray source known.

  1. Sep 9, 2010 #1
    The most extreme ultra-luminous X-ray source, HLX-1 is 300light years from Earth. HLX-1 is the brightest ultra-luminous X-ray source known. Also it is not a supermassive black hole but it is the center of the galaxy. How can it be the brightest x-ray source and be a small black hole?
     
  2. jcsd
  3. Sep 9, 2010 #2

    turbo

    User Avatar
    Gold Member

    Luminosity falls off as the square of the distance from the emitter and the observer. Close enough, and any strong X-ray source (no matter how small) could be the "brightest".
     
  4. Sep 9, 2010 #3

    phyzguy

    User Avatar
    Science Advisor

    Note that it is not 300 light years away, but 300 MILLION light years away. Slightly further.
     
  5. Sep 9, 2010 #4

    D H

    User Avatar
    Staff Emeritus
    Science Advisor

    HLX-1 is in the galaxy ESO 243-49, about 300 million light years from the Earth. It is not at the center of a galaxy; that is one of the hallmarks of an ultraluminous X-ray source. The other hallmark is that they are ultraluminous, which means that their X-ray output exceeds that which would result from a stellar black hole.

    In other words, ultraluminous X-ray sources are neither stellar-mass black holes nor active galactic nuclei. They are something in between, such as an intermediate mass black hole.
     
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook