Milky Way in mid-life crisis
(麻豆淫院Org.com) -- The Milky Way is suffering from a mid-life crisis with most of its star formation behind it, new research from Swinburne University of Technology has shown.
Galaxies typically fall into one of two categories 鈥� energetic blue galaxies that form new stars at an impressive rate, or lethargic red galaxies which are slowly dying.
In a paper accepted for publication in the Astrophysical Journal, Mr Simon Mutch, Dr Darren Croton and Dr Gregory Poole, have shown that our own Milky Way galaxy is neither of these. Rather it is a rare 鈥榞reen valley鈥� galaxy that is half way between a youthful blue galaxy and a geriatric red one.
This is the first time that astronomers have compared both the colour and the star formation rate of the Milky Way to that of other galaxies in the Universe.
鈥淒etermining the state of our own galaxy while we鈥檙e stuck inside it is very difficult to do,鈥� Dr Croton said. 鈥淭he phrase 鈥榠t鈥檚 hard to see the forest for the trees鈥� really rings true here.鈥�
To overcome this, the researchers have taken the best available measurements of the Milky Way from the past 20 years and compiled them into a big picture view of the galaxy's current state.
鈥淭he properties we've looked at all point to the Milky Way having global colours that we'd classify as green 鈥� they鈥檙e midway along an evolutionary track between 鈥榖lue and star forming鈥� and 鈥榬ed and dead鈥�,鈥� Dr Croton said.
According to Mr Mutch, this means that the production of stars in the Milky Way will slow down to a mere trickle over the next few billion years.
鈥淪tar formation in our galaxy will continue to decrease,鈥� he said. 鈥淏ut those concerned about the Milky Way鈥檚 decline needn鈥檛 worry just yet 鈥� retirement is still a long way off.鈥�
And according to Dr Poole, even in its twilight years our home galaxy will still have some life left in it.
鈥淚n about five billion years, the Milky Way is expected to merge with neighbouring spiral galaxy Andromeda,鈥� he said. 鈥淭his will liven things up a lot, withy any residual hydrogen gas in both galaxies providing a new, but short-lived, burst of star formation.鈥�
鈥楾he Mid-Life Crisis of the Milky Way and M31鈥� can be downloaded from:
Provided by Swinburne University of Technology
