Austin, Jun 5 (EFE).- The observations made by an international team of astronomers from the National Optical Astronomy Observatory suggest that enormous quantities of space dust in galaxies harboring black holes at their centers could play an important role in hiding them.
NOAO researcher Stephanie Juneau said at a press conference at the 230th American Astronomical Society meeting that the team’s research into galaxy NGC 7582 some 74 million light years from Earth shows that it hides an active black hole that is very obscured.
Moreover, a powerful wind from the black hole creates a ring of gas and dust around the galaxy center that contributes to obscuring it and that ring is some 2,000 light years in diameter, far larger than scientists had thought.
The French researcher is attending the AAS convention from June 4-8 in Austin, where 600 scientists will be discussing their latest astronomical discoveries.
Juneau held a press conference with several other researchers, including Richard O’Shaugnessy, with the Rochester Institute of Technology, and Chris Shrader, with NASA’s Goddard Space Flight Center.
The research headed by Juneau provides a new perspective on the interaction between black holes and their host galaxies, given that to date scientists had thought that hidden, but active, black holes could only produce a compact dust and gas ring quite close – just a few light years – to their location in the galaxy center.
Supermassive black holes are literally invisible to us, because they emit no light, but with material falling into them they heat do up and produce radiation that can be observed, Juneau said.
The process, which occurs in an “active” black hole, makes the material detectable in a way that can be seen billions of light years away, but only if the conditions are just right.
Juneau said that the analysis of cosmic rays, which enables scientists to measure how black holes “feed,” shows the existence of a huge ring of matter – gas and dust – that obscures the black hole in NGC 7582.
According to Juneau, obscured active black holes have also been found in galaxies that have merged and that are “very perturbed” as a result.
The NOAO team is now studying other active obscured galactic nuclei to learn about the nature of the material there and determine if the results found to date are common or rare.
