1/ Right, I thought I'd have a go at a #tweetstorm. The thread covers my PhD research @Swinburne & @ICRAR into how #galaxies evolve. If you’re into space and/or interested in what astronomers do, read on. If not, well you never know what you'll like so take a peek anyway...
2/ BACKGROUND: One of the great discoveries of the twentieth century was that our Milky Way is just one of billions of galaxies, each one different from the last.
3/ Despite this diversity, galaxies in the local Universe mostly fall into one of two categories; either they contain large amounts of gas which fuels ongoing star formation, or else their gas has been exhausted and star formation has ceased.
4/ This picture is governed by the physics that drives galaxy formation and evolution so in order to have a successful theory of how galaxies evolve, we must explain its origin. This is the underlying aim of my research.
5/ ME: My research uses more than 30,000 galaxies, the largest sample of gas, star formation and environment information that’s available.
6/ We look to reveal where and how gas content regulates galaxy evolution, and how the internal and external mechanisms at play combine to shape the local galaxy population.
7/ We did the first study to be representative of the entire galaxy population and comprehensive enough that the independent influence of different galaxy properties on gas content can be established
8/ By quantifying these relationships between galaxy gas, star formation and the environment, we found that star formation activity, not stellar mass (the mass of stars), is the most important property when it comes to the gas content.
9/ As the gas inside galaxies is used up, it's topped back up (like a tank of fuel) by gas flowing in through the galactic halo from the so-called “cosmic web” that connects them.
10/ Our results in this area demonstrates that fluctuations in the rate of gas supply is a key driver of galaxy chemistry (metals). (ASIDE: Astronomers call all elements apart from hydrogen and helium 'metals' - weird huh?
11/ The other thing we did was to investigate how environment kills galaxies. We find a phenomenon called ram-pressure stripping is more prevalent than previously thought, rapidly sweeping gas from galaxies and depriving them of the material to make new stars.