Researchers found that supermassive black holes emit incredible amounts of hydrogen gas at astounding rates. The finding is a key clue in the mysterious evolution of galaxies, and it may help us understand the future of our own.
Our galaxy, the Milky Way, most likely has a supermassive black hole at its galactic nucleus. This kind of black hole is hundreds of thousands to billions of solar masses and now, scientists are finding that in the process of releasing vast amounts of hydrogen gas, these black holes expel much of the cold gas entirely from their galaxies. Yet cold gases are necessary for the formation of new stars.
Scientists have already incorporated hydrogen gas emission into supermassive black hole models, but what they found the most intriguing and peculiar was how the gas molecules accelerate. Researchers from the University of Sheffield in the UK, the Netherlands Institute of Radio Astronomy, and the Center for Astrophysics at Harvard worked together to understand how fast the hydrogen gas is expelled due to the black hole.
By observing another galaxy with a supermassive black hole-the IC5063 galaxy-with the European Southern Observatory (ESO) Very Large Telescope, researchers were not only able to see most of the cold gas expelled from the system, but were also able to measure the velocity of the gas. The gas was emitted at one million kilometers an hour, or a little over 621,000 mph. Further analysis of the data showed that high energy jets of electrons, moving almost at the speed of light, are responsible for the acceleration of the gas emission.
Why is this so interesting and, furthermore, why is it important? Researchers predict that our galaxy will collide with its neighbor, the Andromeda galaxy, in 5 billion years. The impact will concentrate gas at the nucleus of the galaxy, triggering the electron jets in the supermassive black hole. The study, which was published in Nature, now tells us that this collision will likely expel the remaining cold gas from the galaxy, possibly halting the formation of new stars.
Another galaxy, Messier 106, is undergoing a similar transition, and NASA has a front row seat. Using its Spitzer Space Telescope, the Chandra X-ray Observatory and the Herschel Space Observatory, NASA retrieved stunning images of the energetic jets from Messier 106's black hole. The shock waves from the jets push the gases out of the galaxy.
"Jets from the supermassive black hole at the center of Messier 106 are having a profound influence on the available gas for making stars in this galaxy," says Patrick Ogle, an astrophysicist at California Institute of Technology and a researcher of the black hole-jet phenomenon. "This process may eventually transform the spiral galaxy Messier 16 into a lenticular galaxy, depriving it of the raw material to form stars."
The same thing is likely to happen to our galaxy, it seems. Luckily, 5 billion years is a long wait.