Astronomers have discovered a galaxy with the lowest level of oxygen ever detected. Oxygen is a by-product of stellar processes – the more oxygen that is present, the older a galaxy is. Thanks to machine learning software, researchers have now discovered a galaxy that has 1.6 percent of the oxygen present in the Sun.
The galaxy is known as HSC J1631+4426 and it is located 450 million light-years from Earth. The record-breaking level of oxygen suggests this galaxy has just started forming stars. The findings are reported in The Astrophysical Journal.
The discovery of such a galaxy was only possible due to incredible software that can analyze the vast amount of data collected by the Subaru Telescope. Out of over 40 million galaxies observed by Subaru, the software picked 27 interesting candidates. HSC J1631+4426 had the lowest level of oxygen.
"To find the very faint, rare galaxies, deep, wide-field data taken with the Subaru Telescope was indispensable," lead author Dr Takashi Kojima, from the University of Tokyo, said in a statement.
The galaxy is exciting because it represents an object starting to form late in the history of the universe, which could provide us with new insights into galaxy formation. Due to the expansion of the universe, matter won’t always coalesce into forming new stars and galaxies. This one might be among the last galaxies to be born. Another property that distinguishes HSC J1631+4426t from galaxies like our own Milky Way is how incredibly light it is.
"What is surprising is that the stellar mass of the HSC J1631+4426 galaxy is very small, 0.8 million solar masses. This stellar mass is only about 1/100,000 of our Milky Way galaxy, and comparable to the mass of a star cluster in our Milky Way," said Professor Masami Ouchi of the National Astronomical Observatory of Japan and the University of Tokyo.
Galaxies such as this are an incredibly rare find. The team are hopeful it will provide more insight into galaxy evolution.