BOZEMAN – A study published this month by researchers at Montana State University shows black holes in a new light. Instead of acting as a destructive cosmic force, at least one black hole appears to be helping to form new stars.

Published in the Jan. 20 issue of the journal Nature, the study examines Henize 2–10, a dwarf galaxy 30 million light-years from Earth in the southern constellation Pyxis, whose core contains a massive black hole with a mass of approximately one million Suns. The relatively tiny galaxy contains less than a tenth the number of stars found in our own Milky Way galaxy.

Amy Reines, Asst Professor of Physics, Montana State University (MSU Photo)
Amy Reines, Asst Professor of Physics, Montana State University
(MSU Photo



With data from NASA’s Hubble Space Telescope, authors Zachary Schutte, a graduate student, and Amy Reines, an assistant professor, both in the Department of Physics in MSU’s College of Letters and Science and the eXtreme Gravity Institute at MSU, found that the black hole  in Henize 2–10 is expelling ionized gases in a long filament.

Outflowing material traveling at about 1 million miles per hour is striking an area of dense gases about 230  light-years away from the black hole, where many stars have been recently formed.

“From the beginning I knew something unusual and special was happening in Henize 2–10, and now Hubble has provided a very clear picture of the connection between the black hole and a neighboring star forming region,” Reines said in a NASA press release.

In many larger galaxies, central massive black holes produce jets of radiation moving near the speed of light. Any gas clouds caught in the path would be heated beyond their ability to form new stars. But the authors say that the outflow from the black hole in the dwarf galaxy Henize 2–10 is much slower and gentler, and observations indicate that it’s actively helping star formation instead of hindering it.

“At only 30 million light-years away, Henize 2–10 is close enough that Hubble was able to capture both images and spectroscopic evidence of a black hole outflow very clearly. The additional surprise was that, rather than suppressing star formation, the outflow was triggering the birth of new stars,” Schutte told NASA.

Reines has been searching the skies for black holes for a decade. As a graduate student at the University of Virginia, she found evidence that Henize 2–10 was home to a massive black hole, which at the time ran contrary to the general theories about dwarf galaxies.

Her findings were published in Nature in 2011, and her discoveries have energized the search for black holes in dwarf galaxies, as she and other scientists attempt to discover how these massive black holes form. Dwarf galaxies like Henize 2–10 can offer clues to massive black hole formation that larger galaxies cannot, since they haven’t undergone as much growth as giant galaxies like the Milky Way. They may offer a glimpse of what black holes were like in the early universe.

In addition to the Nature publication, Reines also published an article on Jan. 21 in the journal Nature Astronomy where she discusses the current state of studies into massive black holes in dwarf galaxies, as well as future prospects for the field.

The eXtreme Gravity Institute at MSU brings together physicists and astronomers to study phenomena where the forces of gravity are so strong, they blur the separation between space and time, such as the big bang, neutron stars and black holes.

- by  MSU News Service -