SYDNEY (XINHUA) - Galaxies are being killed in one of the most extreme regions of the universe and an international team of astronomers believe they now know why, according to a latest research.
In a paper published on Wednesday (Nov 3) in the Astrophysical Journal Supplement Series, the 36 astronomers including those from Australia provided evidence that the extreme environments surrounding galaxies can reach far within them and "steal" their molecular gas, the fuel needed to birth new stars and keep a galaxy alive.
"We know that galaxies in the most extreme environments suffer tremendously, losing their gas reservoirs and eventually being unable to form any more stars," said Dr Claudia Lagos from the International Centre for Radio Astronomy Research at the University of Western Australia.
The findings are based on observations of molecular gas in 51 galaxies belonging to the Virgo Cluster, which researchers have mapped as part of their Virgo Environment Traced in Carbon Monoxide Survey (Vertico).
"For a galaxy that's the equivalent of dying, Vertico offers us an unprecedented window on how the molecular gas, the direct fuel for new stars, is affected," Dr Lagos said.
"We were able to create among the most detailed maps of the distribution of gas in cluster galaxies ever observed."
She added: "These images provide the missing pieces of the puzzle of how the environment affects the gas content of galaxies, especially the dense and cold gas, and hence their ability to form stars."
The researchers said galaxy clusters are among the largest, hottest, and most extreme environments in the universe, "making them the perfect cosmic laboratory for observations such as Vertico".
The Virgo Cluster, which is about 65 million light years from Earth, contains thousands of galaxies hurtling through superheated plasma at speeds of up to several million kilometres per hour.
It is an environment so inhospitable that entire galaxies can be stopped from forming stars in a process known as "galaxy quenching".
Said lead author Toby Brown from the National Research Council of Canada: "Gas stripping is one of the most spectacular and violent external mechanisms that can shut down star formation in galaxies.
"The exquisite quality of Vertico's observations allows us to better see and understand such mechanisms."
