It鈥檚 too big a job to do alone. Binary stars may be responsible for shaping the early universe.
When the first stars formed hundreds of thousands of years after the big bang, the universe was too dark for anyone around at the time to spot them. The stars themselves had to emit bright ultraviolet photons first, which carved channels through the gas in their galaxies and escaped into the intergalactic medium. There, the bright light transformed opaque gas into a transparent plasma, like the sun breaking up the fog on a misty morning.
But there is a catch: not enough photons seemed to make it out. Observations of nearby galaxies and models of early galaxies suggest only 1 per cent of all the ultraviolet photons born in early galaxies would have become escapees.
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But other observations of the early cosmos show that 20 per cent of these photons actually are freely streaming through the space between galaxies.
快猫短视频s thought the problem might stem from the fact that massive stars, which produce most of the ultraviolet photons, are too short-lived. Their photons didn鈥檛 have enough time to clear a pathway out of the galaxy.
鈥淚t was frustrating, but also interesting,鈥� says of Caltech. 鈥淔or a while we were convinced that we were missing something important.鈥�
Pairs of thieves
And they were. Most stars don鈥檛 travel solo, but instead circle a stellar sibling in a tight binary dance. But due to the sheer complexity, astronomers hadn鈥檛 incorporated binary stars into their models.
Once they did, the percentage of escaping photons jumped from one to 20 鈥� perfectly matching predictions. 鈥淲e were kind of shocked,鈥� says Hopkins. 鈥淚t changed everything completely.鈥�
They key could be that a massive star with a companion can steal fuel from its neighbour, extending its life. This simple trick would buy enough time for the photons to escape the galaxy and clear the intergalactic medium.
鈥淚t鈥檚 an experiment that combines the best possible effort to simulate a galaxy with our best theoretical understanding of the stars that should live within a galaxy,鈥� says from the University of California, Riverside. Still, he would like to actually see such photons escaping early galaxies.
Hopkins agrees. 鈥淭his potentially closes [the problem] on the modelling and theory side,鈥� he says. 鈥淭he last piece though that I think we really need is the definitive proof that this is happening, which means measuring how many photons are really escaping from these galaxies during this epoch.鈥� It鈥檚 not a terribly easy feat, but with a couple tricks the James Webb Space Telescope, set to launch in 2018, will get much closer to an answer.
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