As summer approaches, we can see examples of punting in more than just local playing fields. In addition to balls being punted halfway across a field, it looks more and more like 6 billion solar mass black holes can also be punted to vast distances across a galaxy.
Now black holes are, as the name implies, completely black. The good news is that they can be spotted anyway for the cases in which the surrounding gas or even stars get too close to the black hole and start funneling onto it. In such cases the black hole can become piercingly bright.
In fact the black hole is so bright that there is too much glare to see the fainter galaxy underlying it. Recently, astronomers have found a way to block out this extra glare from the ultra-bright supermassive black hole.
Somewhat surprisingly, in a couple of cases a considerable offset is measured in the center of the galaxy compared to the center of the black hole. The only way this can be explained is if the black hole was kicked out of the center. How can this happen to a 6 billion solar mass object, afterall?
Well it turns out that it is not just gas and stars that can infall onto the central supermassive black hole. Also, other smaller black holes settle into the center and get consumed by the central supermassive one.
If the impactor is fairly large, then the coalescence of the two objects can induce a strong ‘kick-off’ velocity that punts the whole combined heavyweight black hole out of the galaxy center. In fact, if our own supermassive black hole at the center of the Milky Way would suffer such a collision, this kick-off velocity would be powerful enough to send the entire supermassive black hole beyond the orbit of the Sun. That corresponds to a 33,000 light year punt – Go Team!