Chandra X-Ray Observatory: Double Black Holes

This image from the Chandra X-ray Observatory shows the central region of the starburst galaxy M82 and contains two bright X-ray sources of special interest.

New studies with Chandra and ESA's XMM-Newton show that these two sources may be intermediate-mass black holes, with masses in between those of the stellar-mass and supermassive variety.

These "survivor" black holes avoided falling into the center of the galaxy and could be examples of the seeds required for the growth of supermassive black holes in galaxies, including the one in the Milky Way.

This is the first case where good evidence for more than one mid-sized black hole exists in a single galaxy.

The evidence comes from how their X-ray emission varies over time and analysis of their X-ray brightness and spectra, i.e., the distribution of X-rays with energy.

These results are interesting because they may help address the mystery of how supermassive black holes in the centers of galaxies form. M82 is located about 12 million light years from Earth and is the nearest place to us where the conditions are similar to those in the early Universe, with lots of stars forming.