The most powerful space telescope currently in operation has zoomed in on a single dwarf galaxy around the galaxy, photographing it in stunning detail.
About 3 million light years from Earth, dwarfs galaxynamed Wolf-Lundmark-Melotte (WLM) to the three astronomers who helped find it, and it’s close enough that James Webb Space Telescope (JWST) can distinguish individual stars while still studying large numbers bintang the same time. The dwarf galaxy, in the constellation of Cetus, is one of the most distant members of the Local Group of galaxies that contains our galaxy. Its isolated nature and lack of interaction with other galaxies, including Milky Waymakes WLM useful for studying how stars develop in smaller galaxies.
“We thought WLM didn’t interact with other systems, which made it really interesting to test our theories on the formation and evolution of galaxies,” said Kristen McQueen, an astronomer at Rutgers University in New Jersey and lead research scientist on the project. declaration of the Space Telescope Science Institute in Maryland, which operates the observatory. “Many other nearby galaxies are intertwined and intertwined with the Milky Way, which makes them more difficult to study.”
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McQueen points to a second reason why WLM is such an attractive target: its gas is very 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 heavier elements, the gas in the WLM lost its share of these elements due to a phenomenon called the galactic wind. These winds come from supernovae, or exploding stars. Because WLM has such a small mass, these winds can push the material out of the dwarf galaxy.
In the JWST images for the WLM, McQuinn describes seeing a group of single stars at different points in their evolution with varying 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 interesting features such as huge tidal tails, structures made of stars, dust and gas created by the gravitational interactions between galaxies.
JWST’s main goal in the WLM study is to reconstruct the history of the stellar birth of dwarf galaxies. “Low-mass stars can live for billions of years, which means some of the stars we see today in WLM formed in the early universe,” McQueen said. “By determining the properties of this low-mass star (such as its age), we can gain insight into what happened in the very distant past.”
This work complements the study of galaxies in the early universe that was facilitated by JWST and also allows telescope operators to verify the calibration of galaxies. NIRCam tool who takes sparkling photos. This is possible because both the Hubble Space Telescope and the now retired Spitzer Space Telescope have already studied dwarf galaxies and scientists can compare the images.
“We use WLM as a kind of benchmark to make sure we understand the JWST record,” said McQueen. “We want to make sure that we actually measure the star’s brightness very accurately and accurately. We also want to make sure we understand our model of stellar evolution in the near infrared. “
He said McQuinn’s team is currently developing publicly available software that can measure the brightness of all individually resolved stars in NIRCam images.
“This is an important tool for astronomers around the world,” he said. “If you want to do something with the stars that are planned and grouped together in the sky, you need a tool like this.”
The WLM research team is currently awaiting peer review.
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