Hydrogen detected three billion light years
5 Jan 2015 by hjqbcptqcm.d hjqbcptqcm.d
Astronomers have detected faint signals of hydrogen gas at a record distance of three billion light years from Earth.
Dr Barbara Catinella and Dr Luca Cortese, astronomers from the Swinburne University of Technology in Australia, have detected a signal emitted by atomic hydrogen gas at three billion light years from Earth. They managed to break the record of 500 million light years by applying the world’s largest radio telescope as part of the Square Kilometre Array (SKA) project. Cortese explained: "The signals are not only weak, but they appear at radio frequencies that are used by communication devices and radars, which generate signals billions of times stronger than the cosmic ones that we are trying to detect."
Their paper, published in the journal Monthly Notices of the Royal Astronomical Society, reveals a population of galaxies hosting huge reservoirs of hydrogen gas. The 305m diameter Arecibo radio telescope was applied in their study to locate and estimate these gas-rich systems, each between 20 and 80 billion times the mass of the Sun. Detecting atomic hydrogen emissions from distant galaxies is a challenging task. "Because of the limitations of current instruments, astronomers still know very little about the gas content of galaxies beyond our local neighbourhood" said Catinella.
The Square Kilometre Array project focuses mainly on measuring the atomic hydrogen signal emitted by distant galaxies. The project started as an experiment to explore the abilities of astronomers to detect the atomic hydrogen signal in galaxies.
"Not only did we detect radio signals emitted by distant galaxies when the Universe was three billion years younger, but their gas reservoirs turned out to be unexpectedly large, about 10 times larger than the mass of hydrogen in our Milky Way. Such a huge amount of fuel will be able to feed star formation in these galaxies for several billion years in the future" said Catinella.
Paper:
http://www.nature.com/nature/journal/vaop/ncurrent/full/nature14015.html?WT.ec_id=NATURE-20141127
