For the first time ever, astronomers have found molecular oxygen, the same gas mankind needs to breathe — in a galaxy outside the Milky Way. Oxygen is the third most common element right after hydrogen and helium. Astronomers once vaguely thought molecular oxygen, O2, would be common in the space between the stars. Despite decades of the hunt, astronomers had not found the presence of oxygen in the interstellar environment— until now.
Now, for the first time ever, a team of researchers from Shanghai Astronomical Observatory have recognized the presence of oxygen molecules. It is located outside the Milky Way in a galaxy named Markarian 231. It lies at a distance of 560 million light-years away in the constellation Ursa Major.
With the help of telescopes, this galaxy was observed for four successive days. They then studied the emissions from oxygen molecules across a number of wavelengths. Researchers chose the Markarian 231 because it emits red-shifted light at a long wavelength. It can travel across space to our planet and is easily observable. The Markarian 231 is powered by a highly active supermassive black hole at its centre, called a ‘quasar’. It emits bright light and is regarded as one of the most energetic objects in the universe.
Researchers believe that the presence of oxygen in such a zone may be due to the interaction between the AGN-driven molecular outflow and the outer disc molecular clouds. The observations were made using the IRAM 30-metre radio telescope situated in Spain, and the Northern Extended Millimeter Array (NOEMA) in France. The team compared the data with past detection of the oxygen molecules. It highlighted that the number of O2 molecules present in Markarian 231 was around 100 times higher than that found in Orion. Moreover, evidence suggests that the galaxy has a higher abundance of O2 compared to hydrogen.