Astronomers witness slow death of a dwarf galaxy close to the Milky Way

The galaxy is losing its hydrogen and the ability to form new stars

A dwarf galaxy dubbed the Small Magellanic Cloud (SMC) is slowly approaching its death due to the gradual loss of energy to form stars, says new research by the scientists from the Australian National University and CSIRO (the Commonwealth Scientific and Industrial Research Organisation).

According to astronomers, the dwarf galaxy SMC sits close to the Milky Way. It is very small in size and mass compared to our own galaxy, which will eventually consume it.

The astronomers tracked SMC using CSIRO's Australian SKA Pathfinder (ASKAP) radio telescope array. ASKAP is an advanced telescope featuring radio receivers that enable it to capture finer pictures and a panoramic view of the sky.

ASKAP's images of SMC were more than three times finer than the images captured by other telescopes. With ASKAP, it was possible to photograph the entire galaxy in a single shot.

Using new images, astronomers were able to accurately investigate interactions between the SMC and its environment.

Professor Naomi McClure-Griffiths from ANU - the lead researcher on the study - revealed that her team was actually studying the evolution of galaxies in the universe when they noticed the outflow of hydrogen gas from the SMC. Hydrogen is the primary constituent of stars, and the galaxies that lose all of their hydrogen can no longer form new ones.

Such galaxies eventually "fade away into oblivion," according to McClure-Griffiths.

McClure-Griffiths considers the finding to be highly significant, as it suggests that SMC could be a possible source of gas for the huge Magellanic Stream that encircles the Milky Way.

The team plans to use ASKAP to capture detailed images of hydrogen gas present in the Magellanic Clouds and in the Milky Way to understand how SMC is merging with our own galaxy.

Detailed findings of the study are published in Nature Astronomy.