The most powerful space telescope in operation has been zoomed in on a single dwarf galaxy in our galaxy, capturing it in jaw-dropping detail.
Nano, about 3 million light years from Earth galaxyWolf-Lundmark-Melotte (WLM) is named after the three astronomers who played an instrumental role in its discovery. James Webb Space Telescope JWST can distinguish individual stars while studying large numbers at the same time stars At the same time. The dwarf galaxy in the Cetus constellation is one of the most distant members of the Local Group of galaxies that contains our galaxy. It is isolated and has no connection with other galaxies Milky WayMake WLM useful for studying how stars form in small galaxies.
“We think WLM does not interact with other systems, which makes it very good at testing our theories on the formation and evolution of galaxies,” said Kristen McQueen, an astronomer at Rutgers University in New Jersey and lead scientist on the project. Research. a report From the Space Telescope Science Institute in Maryland, he runs the observatory. “Many nearby galaxies are intertwined with the Milky Way, which makes it difficult to study.”
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McQueen pointed to a second reason why WLM is an interesting target: its gas is similar to that of galaxies in the early universe, with no elements heavier than hydrogen and helium.
But while the gas from those early galaxies never contained heavy elements, the gas in WLM lost its share of these elements due to a phenomenon known as galactic winds. These winds come from supernovae, or exploding stars. Because the WLM is so small, these winds push the material out of the dwarf galaxy.
In this JWST image for WLM, McQuinn described seeing a group of single stars at different points in their evolution with different colors, sizes, temperatures and ages. The image also shows clouds of molecular gas and dust called nebulae, which contain the raw material for star formation within the WLM. In the background galaxies, JWST can detect fascinating features such as huge tide tails, structures composed of stars and dust and gases formed by the gravitational interactions between galaxies.
JWST’s primary goal in the WLM study is to reconstruct the star’s birth date for the dwarf galaxy. “Low-mass stars can live for billions of years, which means some of the stars we see in the WLM formed in the early universe,” McQueen said. “By determining the characteristics (such as their age) of these low-mass stars, we can gain insight into what was happening in the very distant past.”
This work complements the study of galaxies in the early universe, which JWST already facilitates, and allows telescope operators to examine their calibration. NIRCam tool which caused the image to flash. This is possible because both the Hubble Space Telescope and the now retired Spitzer Space Telescope have previously studied the dwarf galaxy, so scientists can compare the images.
“We are using the WLM as a kind of benchmark to make sure we understand the JWST notes,” said McQueen. “We want to make sure we measure the brightness of the stars accurately and accurately. We also want to make sure we understand our patterns of stellar evolution in the near infrared. “
McQuinn’s team is currently developing a software tool that can be used by anyone who can measure the brightness of all individually resolved stars in NIRCam images.
“It is an essential tool for astronomers around the world,” he said. “If you want to do anything with crucial stars clustered together in the sky, you need a tool like this.”
The team’s WLM research is currently awaiting peer review.
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