Scientists have had another break in the case of black hole evolution, according to a new study that used NASA's Chandra X-ray Observatory for imaging.
"In paleontology, the discovery of certain fossils can help scientists fill in the evolutionary gaps between different dinosaurs," said study lead Mar Mezcua of the Harvard-Smithsonian Center for Astrophysics, according to the press release. "We do the same thing in astronomy, but we often have to 'dig' up our discoveries in galaxies that are millions of light-years away."
Scientists believe the object, NGC2276-3c, is an "intermediate-mass black hole" (IMBH). It is located in an arm of the spiral galaxy NGC2276 located about 100 million light-years from Earth.
IMBHs fall between smaller black holes with five to 30 times the mass of the sun and supermassive black holes which can have a few hundred to a few thousand solar masses. Astronomers think that IMGHs can be "seeds" for supermassive black holes that formed in the universe's younger years.
"Astronomers have been looking very hard for these medium-sized black holes," said co-author Tim Roberts from the University of Durham, U.K., according to the press release. "There have been hints that they exist, but the IMBHs have been acting like a long-lost relative that isn't interested in being found."
To study NGC2276-3c, the researchers used X-rays with Chandra and radio waves with the European Very Long Baseline Interferometry (VLBI) Network. The mass of NGC2276-3c was estimated to be about 50,000 times that of the sun, which puts it in the range of IMBHs. "We found that NGC2276-3c has traits similar to both stellar-mass black holes and supermassive black holes" said co-author Andrei Lobanov of the Max Planck Institute for Radio Astronomy in Bonn, Germany, according to the press release. "In other words, this object helps tie the whole black hole family together."
The IMBH's mass was notable as was the powerful radio jet it produces that extends up to 2,000 light-years, according to the press release. The absence of young stars in the area of the jet's path suggests NGC2276-3c has a remarkable influence on its surroundings. The jet could have cut a path in the gas that stunted new star growth.
Other questions about NGC2276-3c relate to its location. Was it part of the galaxy when it formed or is it an orphan of a dwarf galaxy that crashed into and merged with NGC2276? Anna Wolter, from the National Institute for Astrophysics (INAF) in Milan, Italy, believes that the formation of five to 15 solar masses worth of stars each year in NGC2276 supports the theory that a collision with a dwarf galaxy could have triggered the formation of NGC2276-3c.
The results of the observations have been published in separate papers by Mezcua, Wolter and their colleagues in Monthly Notices of the Royal Astronomical Society.
NASA's Marshall Space Flight Center in Huntsville, Ala., manages the Chandra program for NASA's Science Mission Directorate in Washington, D.C. The Smithsonian Astrophysical Observatory in Cambridge, Mass., controls Chandra's science and flight operations.
