Gorgeous Galactic Gamma-Ray Globs
Beautiful and complex Gamma Ray bubbles attached to our galaxy continue to defy explanation
Four years ago, scientists pouring through the data from the orbiting Fermi Gamma Ray telescope discovered these wonderful lobes of light emanating from our galactic core. They kinda look like twin bubble gum bubbles being blown up by our supermassive black hole.
They consist primarily of my favorite type of radiation, Gamma rays, which are the most energetic form of light in the entire electromagnetic spectrum of which visible light is just a tiny sliver. This kind of light can be found naturally on earth from sources like lightning strikes and also from unnatural sources like a nuclear bomb. This type of radiation is ionizing meaning it doesn’t play well with biological things so if anyone shines a gamma ray flashlight at you (not invented yet), I suggest you run away.
The universe is awash however in gamma radiation but we never really knew that since our atmosphere blocks all but the most energetic from our detectors. Once we lofted the proper instrumentation into earth orbit though, it was clear that there was plenty of it from lots of different sources (pulsars, supernovas etc).
This is actually part of the reason why these bubbles are so hard to examine in fine detail. There’s so much gamma radiation out there that astronomers had to selectively and painstakingly filter all other extraneous sources. Once they did, the bubbles popped out in all their glory.
In an attempt to figure these guys out, astronomers have been recently going through the most recent Fermi data and data from other sources. Here’s some of what they’ve learned:
- The 30,000 light-year-tall bubbles are clearly delineated from surrounding space
- They glow uniformly throughout their surface changing from microwave and gamma at the base to just gamma about two-thirds of the way up
- The uppermost reaches contain the most energetic gamma rays but they have no apparent source or cause
Causes for the bubbles have been theorized but none are as fully satisfying as astronomers would like. This includes matter that has been blown away by the supermassive black hole or perhaps it could be from many stars near the black hole that all went supernova around the same time.
Some even contend that some of this radiation could be due to dark matter annihilation. That would be cool.
We’ll have to wait a bit before we truly know what’s going on here. It’s just amazing to me the beauty and complexity that can be wrought from a simple gargantuan cloud of hydrogen when you add a lot of time plus a dash of the laws of physics.
I look forward to the time I can travel closer to the center of our galaxy with my selectively-filtered gamma ray eyes and behold this beauty for myself.
Image Credit:NASA’s Goddard Space Flight Center