The heart of our Milky Way galaxy has a mysterious structure that could help astronomers understand the birth of stars. The James Webb Space Telescope (JWST) has captured a stunning image of this dense center of our galaxy with clarity never seen before, offering scientists a treasure trove of astronomical phenomena.
The first glimpse of this region reveals a bustling cluster of protostars within an infrared-dark cloud. Protostars are the building blocks of stars, and the new images from JWST reveal that these nascent stars are accumulating mass. This accretion creates massive outflows of gas that glow intensely in the infrared spectrum, akin to embers in a cosmic bonfire. The infrared images from the telescope also show cavities and filaments of molecular hydrogen that have been shocked by the protostar’s ejecta, creating pockets of orange in the image.
Another discovery comes from the observatory’s Near-Infrared Camera, which has spotted a massive pocket of hot gas surrounded by this stellar region, depicted in cyan in the image. Astronomers are trying to determine what is generating this vast amount of energized hydrogen, far exceeding what would be released by young massive stars in such an environment.
In addition to this giant bubble, a massive collection of stars has been found in the region to the lower right of the supermassive black hole. These are known as the poor old heart stars, a population of very metal-poor stars that formed in the early days of the Milky Way during their teenage years. These old stars fit nicely into Xiang and Rix’s earlier study, which established a chronology for thick-disk formation in the Milky Way, suggesting that these stars are more than 12.5 billion years old.
Finally, the images from the telescope have revealed an example of the phenomenon of gravitational lensing in action, caused by a massive galaxy cluster — called SMAGS 0723 — that is warping and magnifying the light of distant galaxies behind it. This effect is one of the reasons that Webb can see so much more detail in these images than any previous telescope.
The image from the telescope, published in Science on Monday, is just the latest chapter in a long series of stunning images produced by NASA’s flagship mission. Its dazzling resolution has allowed the telescope to probe the cosmos down to scales of about one to two meters per pixel, revealing structures in unprecedented detail. This is a significant step toward unraveling the mysteries of our Universe. The JWST is currently undergoing final preparations for its 2020 launch from French Guiana and is expected to begin science operations in 2021. The observatory’s mission operations center is at the Space Telescope Science Institute in Baltimore, Maryland. The National Science Foundation and NASA fund the observatory. For more information about JWST, visit http://www.nasa.gov/jwst. The JWST is the largest, most powerful telescope in the history of the United States, and it will allow us to discover new worlds of detail about our universe, from star and planet formation to distant galaxies.