Celestial Gases Fuel A Masing Discovery

Although lasers tend to overshadow their microwave-emitting counterparts known as masers, naturally occurring celestial masers do help scientists learn more about black holes and galaxies, which could lead to a better understanding of hypothetical dark energy. Researchers from China have discovered two new types of masers using the IRAM 30-meter telescope in Spain: one formed by silicon monoxide and the other by methanol (Nat. Commun. 2014, DOI: 10.1038/ncomms6449). Prior to this study, astronomers had identified only water, hydroxide, and formaldehyde masers in space. Natural masers consist of gas clouds in which a majority of the molecules have been excited by energy from objects, such as a black holes. As the molecules relax, they emit microwave radiation. The two new masers are considered “megamasers” because they are at least a million times more luminous than masers found in our Milky Way galaxy. A supermassive black hole is likely energizing the molecules in the newfound SiO megamaser, which is located in a galaxy roughly 50 million light-years from Earth, says study leader Junzhi Wang, an astronomer at the Shanghai Astronomical Observatory of the Chinese Academy of Sciences. But the scientists aren’t yet sure what’s powering the methanol megamaser in the same galaxy and will need higher-resolution observations to confirm its source.