Record-Breaking Natural Laser Discovered 11 Billion Light-Years Away
This illustration of the distant galaxy HATLAS J142935.3-002836, located 11 billion light-years away, shows how a red ring of light was created via the gravitational lensing of a foreground mass. Splitting up the radio light into different colours, as a prism does, reveals the hydroxyl megamaser, whose spectral signature confirms its nature, exhibiting blended 1667 and 1665 MHz emission features. This new megamaser is so remarkable that some are calling it a gigamaser instead of a megamaser. Credit: Inter-University Institute for Data-Intensive Astronomy (IDIA)
Here on Earth, the very idea of a laser is relatively novel,having only been invented in 1958. The underlying physics is straightforward:
-
an electron within a molecule gets excited to a higher-energy state,
-
the electron de-transitions back to the lower energy state,
-
where it emits light of a very specific wavelength in the process.
Then, pumped or injected energy re-excites an electron within that very same molecule back into that higher-energy state, over and over. This causes light of precisely that same, monochromatic wavelength to get emitted over and over again. So long as you continue stimulating the same transition, you’ll keep getting light of that exact same frequency over and over again, every time.
But out there in the Universe, this exact phenomenon occurs naturally in a number of galaxies at much longer wavelengths than the eye can see: in the microwave portion of the spectrum. Astrophysically, these objects are known as masers, and arise when energy gets injected into large populations of molecules that are only allowed to de-excite in specific ways. Using the MeerKAT array, scientists in 2022 identified the strongest, most distant maser ever seen: an object so strong that it emits more power, just in that one emission line we can observe, than the total sum of all the light emitted from 6000 Suns. Then, just a couple of weeks ago, a new hydroxyl megamaser was discovered at an even greater distance: 11 billion light-years away. This record-breaking megamaser really is a laser from space, with a story that’s billions of years in the making.
(Source: Big Think)
