While we were gorging on delicious food and arguing with relatives, Hubble produced some of the finest observations of galaxy IRAS 16399-0937.
This object, which is located 370 million light-years from the Milky Way, is a maser, a sort of natural laser, where the light emission is observable not in visible light but in microwaves (thus the 'm' in maser). IRAS 16399 is not just your regular maser, it's a megamaser – 100 million times brighter than the masers found in galaxies like the Milky Way!
Lasers work on the principle of stimulating light emissions at a specific frequency from a particular gas, and similarly, some galactic gas clouds have the right conditions to produce microwaves, just like this object, again all at the same frequency.
The Hubble observation provides a crystal clear view of this galaxy. The object is peculiarly shaped because it's the product of a collision of two galaxies of roughly the same mass. This galaxy merger is not only responsible for the curious structure of the galaxy, but also for the activities in the two bright cores visible in the space telescope image.
The north core, IRAS 16399N, is known as a LINER, Low-Ionization Nuclear Emission Region, an almost quiet region by galactic standards. On the other end, the south core, IRAS 16399S is in full swing with new stars forming at a rate of dozens, if not hundreds, of times higher than the Milky Way.
But don’t let this difference in activity fool you. The real kicker hides in IRAS 16399N, where a supermassive black hole 100 million times the mass of our Sun hides in waiting surrounded by gas. IRAS 16399N and IRAS 16399S are 11,000 light-years apart, but they are getting closer and closer to each other.
Eventually, the two cores will merge and the supermassive black hole will wake up. When that happens in a few hundred million years, powerful jets will heat up the galaxy and choke any new star formation. But for now, and for many years to come, we can enjoy this breathtaking picture of this incredible galaxy.
