Friday, 24 May 2013
Galactic crash solves cosmic mystery
The galactic merger, rumored within the journal Nature, can end in the creation of an enormous elliptical galaxy, eleven times larger than our own galaxy, the Milky Way System.
Scientists, together with the paper\'s lead author Dr Hai Fu of the University of Golden State, Irvine, area unit closely observance the collision between the 2 gas-rich galaxies placed eleven billion light-years away.
\"We see 2 huge galaxies that area unit forming stars at an awfully high speed and area unit close to merge,\" says Fu.
\"No one has seen this before. it is the brightest, most glowing and most gas-rich, sub-millimetre-bright galaxy merger glorious.
\"We area unit seeing these galaxies merging at a time once the universe was but 3 billion years recent.\"
Fu says the 2 galaxies area unit regarding sixty,000 light-years aloof from one another - roughly adequate the gap between the Sun and also the centre of our galaxy.
\"We see material being stripped aloof from the 2 galaxies ... you\'ll see there\'s a bridge of fabric connecting the 2, meaning they\'ve already passed one another your time agone and area unit in a very [gravitational] dance,\" Fu says.
The merger is manufacturing the new mega-elliptical galaxy, that has been named HXMM01, and can have four hundred billion times the mass of the Sun.
The discovery is very vital as a result of it represents a transformation introduce galaxy evolution.
\"Galaxies are available 2 flavours, they\'re either red ellipticals or blue spirals,\" says Fu.
\"And there area unit only a few galaxies that lie between those 2 populations. we predict this represents a transition from one sort to the opposite.
\"This bridges the 2 varieties, and shows North American nation however galaxies evolve from blue spirals into red ellipticals.\"
The cosmic collision was discovered by UC Irvine postdoctoral scholar Julie Wardlow in pictures taken by the ecu area Agency\'s Earth orbiting Herschel area telescope, that was retired last month.
Wardlow detected \"an wonderful, bright blob\" in Herschel pictures of regions wherever cold gas and mud area unit coming back along to create new stars.
\"Herschel captured carpets of galaxies, and this one extremely stood out,\" says Wardlow.
The discovery additionally explains the long-standing cosmic mystery of however ellipticals, the foremost huge galaxies nowadays, may kind thus quickly, and then early within the history of the universe, and why they then stop creating new stars.
According to Fu, the gravitative waltz created by the merging galaxies, generates extraordinarily intense star formation.
He estimates new stars area unit being born at a rate resembling 2000 Sun-like stars a year.
The huge amounts of latest stars being generated by this galactic collision uses up huge amounts of star-making atomic number 1, enough to empty that sector of the universe in regarding two hundred million years.
\"That can result in the new galaxy\'s slow starvation for the remainder of its life,\" says Fu.