Golden age of galaxies explored by scientists
29 Sep 2016 by Evoluted New Media
New data has been used to better understand how star formation in younger galaxies is linked to their total stellar mass by astronomers from Edinburgh University.
New data has been used to better understand how star formation in younger galaxies is linked to their total stellar mass by astronomers from Edinburgh University.
Using the Atacama Large Millimetre/submillimetre Array (ALMA) telescope in Chile, astronomers studied the Hubble Ultra Deep Field and discovered a rapid rise of gas content in galaxies 10 billion years ago.Professor Jim Dunlop, from the University’s School of Physics and Astronomy and co-author of the study, said: “This is a breakthrough result. For the first time we are properly connecting the visible and ultraviolet light view of the distant Universe from Hubble and far-infrared views of the Universe from ALMA.”
The findings trace previously known abundances of star-forming gas at different points in time, allowing scientists to understand more about the golden age, a period which saw rapid increase in star formation believed to be linked to increasing gas content.
The astronomers conducted a fully blind search for cool gas, choosing a quiet area of space to investigate — as opposed to a galaxy or star-forming nebula. ALMA was chosen as it can search for carbon monoxide, a ‘tracer’ molecule that can identify regions rich in molecular gas, primed for star formation.
Roberto Decarli, a member of the research team, said: "These newly detected carbon-monoxide rich galaxies represent a substantial contribution to the star-formation history of the Universe. With ALMA we have opened a pathway for studying the early formation and assembly of galaxies in the Hubble Ultra Deep Field."
The first images of the Hubble Ultra Deep Field were captured with the Hubble Space Telescope and published in 2004. After refurbishment in 2009, the telescope was also able to record near-infrared images. This allowed for early galaxies — created less than one billion years after the Big Bang — to be seen.
The emissions from young stars that are absorbed and re-emitted by clouds of interstellar gas and dust can be ‘seen’ by the astronomers using ALMA. The telescope consists of 66 six and seven metre diameter radio telescopes. ALMA is an international partnership including Europe, the US, Canada, Japan, South Korea and Chile.
The research was published in Monthly Notices of the Royal Astronomical Society.
