MACS1149-JD1, aka JD1, is a galaxy about 13.3 billion years away from us, meaning the light from that galaxy takes 13.3 billion years to reach Earth. This also means that this galaxy was formed only 500 million years after the Big Bang. It was discovered and confirmed to be at this far-away distance in 2012. Recently, a team of astronomers led by a graduate student Tsuyoshi Tokuoka from Waseda University, Japan used the Atacama Large Millimeter/submillimeter Array (ALMA), located in the Atacama Desert in Chile, to find evidence of rotation in this galaxy.
Usually, when objects are moving away from us, the light coming from them is stretched towards lower energy or is what we call redshifted. Therefore, if a galaxy is moving away from us, we would measure the same redshift value from every part of it. If this galaxy was also rotating, we would see differences in the redshift values from different parts of it because the amount of light that is stretched depends on its relative distance from us. This team measured exactly that, i.e., small differences in this redshift value from different parts of the galaxy. They noticed that the northern part of it is moving away slower than the southern part even though the whole galaxy is moving away. It spins at about 112,000 miles per hour, about 4 times slower than our own galaxy.
This is an incredible discovery because the rotation of galaxies sheds light on the formation of galaxies in the early universe. This result confirms that rotation was onset early in the young universe. The detailed research around this discovery was published in the Astrophysical Journal Letters in 2022.
P.S.: The James Webb Telescope, a space telescope that needs no introduction has already agreed to look at this galaxy for more in-depth studies. Stay tuned for more on this soon!
Source: Science News, The Astrophysical Journal Letters
