Black hole family tree's intriguing member discovered

An intriguing member of the Black hole family tree has been discovered, which may help provide answers to some long-standing questions about how black holes evolve and influence their surroundings.

Mar Mezcua of the Harvard-Smithsonian Center for Astrophysics said that in paleontology, the discovery of certain fossils can help scientists fill in the evolutionary gaps between different dinosaurs and they do the same thing in astronomy, but they often have to "dig" up our discoveries in galaxies that are millions of light years away.

The intriguing object, called NGC-2276-3c, is located in an arm of the spiral galaxy NGC 2276, which is about 100 million light years from Earth. NGC-2276-3c appears to be what astronomers call an "intermediate-mass black hole" (IMBH).

To learn about NGC-2276-3c, the researchers observed it at almost the same time in X-rays with Chandra and in radio waves with the European Very Long Baseline Interferometry (VLBI) Network.

The X-ray and radio data, along with an observed relation between radio and X-ray luminosities for sources powered by black holes, were used to estimate the black hole's mass. A mass of about 50,000 times that of the sun was obtained, placing it in the range of IMBHs.

Co-author Andrei Lobanov of the Max Planck Institute for Radio Astronomy in Bonn said that they found that NGC 2276-3c has traits similar to both stellar-mass black holes and supermassive black holes, in other words, this object helps tie the whole black hole family together.

In addition to its mass, another remarkable property of NGC-2276-3c is that it has produced a powerful radio jet that extends for up to 2,000 light years. The region along the jet that extends up about 1,000 light years from NGC-2276-3c seems to be missing young stars.

This provides evidence that the IMBH may have had a strong influence on its environment, as the jet could have cleared out a cavity in the gas and suppressed the formation of new stars. Further studies of the NGC-2276-3c jet could provide insight into the potentially large effects that supermassive black hole seeds in the early universe have had on their surroundings.