A Powerful Wind of Molecules has been detected at a Distance of 12 Billion Light Years
Scientists might have found the self-regulating mechanism of galaxies.
Continuous advancements in technology enable humanity to go deep into space. A couple of months back, astronomers found the brightest object (a quasar) ever discovered in the universe at a distance of 13 billion light years. Before that, Icarus (the most distant star) was also detected. Now, the latest discovery in this domain is revealed as a powerful “wind” of molecules was seen in a galaxy, which is 12 billion light years away from us. Justin Spilker, the name behind this research, explained the behavior of the earliest galaxies. He mentioned that they regulated the birth of stars in order to avoid self-destruction. Talking about galaxies, he said,
“Galaxies are complicated, messy beasts, and we think outflows and winds are critical pieces to how they form and evolve, regulating their ability to grow.”
It is the first occasion when scientists have been able to directly observe these powerful outflows in the very early universe. Spilker was able to observe a powerful wind of molecules in a galaxy when the universe was only 1 billion years old by making use of the Atacama Large Millimeter/Submillimeter Array (ALMA). His findings revealed how these ancient galaxies self-regulated their growth to ensure that they keep forming stars for a longer period of time.
The rates of starbirth vary from one galaxy to another. For instance, starburst galaxies have the ability to produce hundreds or even thousands of stars annually. On the other hand, galaxies like Andromeda and Milky Way make one star every year. In order to prolong their lifespan, some galaxies do decrease their rate of star formation either temporarily or permanently. They do so by ejecting vast quantities of gas into their expansive halos. This gas may escape entirely or comes back in on the galaxy which re-initiates a burst of star formation in the future.
Although researchers have seen similar winds in the nearby starbursting galaxies, all of them agree that the one originating from the SPT2319-55 is the most distant outflow ever observed in the early universe. ALMA made use of a process called Gravitational Lensing to view such a far-off galaxy. Another galaxy which is almost concurrent to the Earth and SPT2319-55 played the role of a gravitational lens. It magnified the background galaxy (SPT2319-55) to an extent where researchers were able to observe it in detail. Specialized computer programs remove the scrambling effects from the image to reconstruct an accurate one. This galaxy was discovered by the South Pole Telescope of the National Science Foundation.
The in-depth research revealed that the wind is escaping in form of discrete clumps to match the speed of star formation. According to the study published in the journal ‘Science’ on the 7th of September, the star-forming gas is exiting the galaxy at about 800 kilometers per hour. It clearly negates the idea that a gentle breeze of molecules is flowing out of the galaxy, SPT2319-55. Hydroxyl (OH) molecules proved extremely beneficial for this research because its millimeter-wavelength signature was absorbed by the galaxy. This essentially offered the shadow of an OH fingerprint in the Infrared light of the SPT2319-55.
Spilker talked about the importance of these winds for the survival of galaxies. They can self-regulate their growth to ensure that they are not becoming too big, too fast. According to his research, there are two possible explanations for these winds. First one of them is that all the supernova explosions associated with rapid star formation combine together to generate these powerful bursts of wind. Secondly, they are possibly triggered by a powerful release of energy which occurs when some of the star-forming gas falls into the supermassive black hole at the center of the galaxy. Spilker suggested that they need to know a lot more before arriving at any certain conclusion by saying,
“So far, we have only observed one galaxy at such a remarkable cosmic distance, but we’d like to know if winds like these are also present in other galaxies to see just how common they are. If they occur in basically every galaxy, we know that molecular winds are both ubiquitous and also a really common way for galaxies to self-regulate their growth.”
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