The most powerful space telescope currently operating has zoomed in on a lone dwarf galaxy in the vicinity of the galaxy, photographing it in amazing detail.
About 3 million light-years from Earth, the dwarf galaxynamed Wolf-Lundmark-Melotte (WLM) to three astronomers instrumental in discovering it, and it’s close enough that James Webb Space Telescope (JWST) can distinguish individual stars while still studying large numbers of stars same time. The dwarf galaxy, in the constellation Cetus, is one of the most distant members of the Local Group of galaxies that contains our galaxy. Its isolated nature and lack of interactions with other galaxies, including Milky Waymakes WLM useful for studying how stars develop in smaller galaxies.
“We think that the WLM did not interact with other systems, which makes it a really cool thing to test our theories about the formation and evolution of galaxies,” said Kristen McQueen, an astronomer at Rutgers University in New Jersey and lead scientist on the research project. statement from the Space Telescope Science Institute in Maryland, which runs the observatory. “Many other neighboring galaxies are tangled and entangled with the Milky Way, which makes them more difficult to study.”
McQueen pointed to a second reason why WLM is an intriguing target: Its gas is very similar to that of galaxies in the early universe, without any elements heavier than hydrogen and helium.
But while the gas of those early galaxies never contained heavier elements, the gas in WLM lost its share of these elements to a phenomenon called galactic winds. These winds originate from supernovae, or exploding stars. Because WLM has so little mass, these winds can push material out of the dwarf galaxy.
In a JWST image for WLM, McQuinn described seeing a group of individual stars at different points in their evolution with a variety of colors, sizes, temperatures, and ages. The image also shows clouds of molecular gas and dust, called nebulae, that contain the raw material for star formation within the WLM. In background galaxies, JWST can detect fascinating features such as massive tidal tails, structures made of stars, dust, and gas created by gravitational interactions between galaxies.
JWST’s main goal in the WLM study is to reconstruct the star birth history of the dwarf galaxy. “Low-mass stars can live for billions of years, which means that some of the stars we see in the WLM today formed in the early universe,” McQueen said. “By determining the properties of these low-mass stars (such as their ages), we can gain insight into what was happening in the very distant past.”
The work complements the study of galaxies in the early universe already facilitated by JWST, and also allows telescope operators to examine the calibration of galaxies. NIRCam Tool that took the sparkling photo. This is possible because both the Hubble Space Telescope and the now retired Spitzer Space Telescope have studied the dwarf galaxy before, and scientists can compare the images.
“We use the WLM as a kind of benchmark to help us make sure we understand the JWST notes,” McQueen said. “We want to make sure that we really, really accurately and accurately measure the brightness of the stars. We also want to make sure that we understand our models of stellar evolution in the near infrared.”
She said the McQuinn team is currently developing a publicly available software tool that can measure the brightness of all individually resolved stars in the NIRCam images.
“This is an essential tool for astronomers around the world,” she said. “If you want to do anything with stars designed and crowded together in the sky, you need a tool like this.”
The team’s WLM research is currently awaiting peer review.
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