In case you haven’t heard, astronomers have discovered the missing matter in our universe. According to the current cosmological model, matter is dispersed through the universe in a 70% dark energy, 25% dark matter, and 5% ordinary matter ratio. The ordinary matter, like we all know and love, has only been measured to around 50% of what they thought was out there. This missing matter was hiding where they thought it might be, but had no direct evidence to show. Until now. This matter was assumed to be in gaseous form residing in the vast distances of space, but we had no way to measure it.
There are these occurences known as FRB’s (Fast Radio Bursts) A FBR was caught recently (last year sometime). With very quick follow ups with other observational telescopes they were able to pinpoint the location of the FRB. Using the redshift analysis they determined this galaxy is 6 billion light years out.
While we can detect FRB’s, they havent been able to get a location on one quick enough to determine it’s location. They got this one. Which is only part of the challenge. Knowing the distance is only 1 key aspect, but a big one.
Now what they know about these FRB’s is the radio waves disperse as they travel through matter in space. The radio waves with higher energy/frequency arrive before the lower frequency waves. The amount of dispersion depends on the amount of matter they encounter. This discrepency combined with the location of the event that caused the FRB allowed them ( I am not sure who they are) to indirectly measure the matter these radio waves traveled through. It fits the model!
This is kind of a big deal actually. When data comes together to confirm a working theory we have what is known as science. Science being the best way known to understand this big old universe we live in. It works so much better than those other ways of knowing, and they can show their work!
I caught this first from Science Daily:
https://www.sciencedaily.com/releases/2016/02/160224231734.htm
Also Phil Plait over at Bad Astronomy did a great write up. I borrowed some of his knowledge of the radio wave dispersion in my write up. Mr. Plait goes into much detail, and considers the causes of FRB’s: