Webb Gives Us a Stunning New Look at This Lonely Dwarf Galaxy: ScienceAlert

Webb Gives Us a Stunning New Look at This Lonely Dwarf Galaxy: ScienceAlert
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James Webb Space Telescope Early Broadcast Science The (ERS) program – first published on July 12, 2022 – has proven to be a treasure trove of scientific findings and breakthroughs.

Among the many research areas it provides is its subject, the Resolved Star Populations (RSTs) study. ERS 1334.

This refers to large groups of stars that are close enough that individual stars can be distinguished, but far enough that telescopes can capture several of them at once. good example, Wolf-Lundmark-Melotte (WLM) Dwarf galaxy adjacent to the Milky Way.

Kristen McQuinn, an assistant professor of astrophysics at Rutgers University, is one of the leading scientists in the Webb ERS program, whose work focuses on RSTs. Lately, Talked to Natasha Piroand NASA senior communications expert on how JWST is enabling new work on WLM.

Webb’s advanced observations revealed that this galaxy did not interact with other galaxies in the past.

According to McQuinn, this makes it a great candidate for astronomers to test their theory of galaxy formation and evolution. Here are the highlights from that interview.

about WLM

WLM is roughly 3 million light-years from Earth, which means it’s pretty close (astronomically) to the Milky Way. However, it is also relatively isolated, leading astronomers to conclude that it has not interacted with other systems in the past.

When astronomers observed other nearby dwarf galaxies, they noticed that they are typically entangled with the Milky Way, suggesting that they are in the process of merging.

This makes it difficult to study them, as populations of stars and gas clouds are indistinguishable from our own.

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Another important thing about WLM is that it is low in heavier elements than hydrogen and helium (very common in the early Universe). Elements such as carbon, oxygen, silicon, and iron formed in the cores of early population stars and were dissipated when these stars exploded in supernovas.

In the case of WLM, which has experienced star formation throughout its history, the force of these explosions pushed these elements out over time. This process is known as “galactic winds” and has been observed in small, low-mass galaxies.

JWST Images

New Webb images provide the clearest WLM view ever seen. Previously, the dwarf galaxy, Infrared Array Camera (IAC) on Spitzer Space Telescope (SST).

These provided limited resolution compared to the Webb images visible in a side-by-side comparison (shown below).

Side-by-side comparison of photographs of the dwarf galaxy Wolf–Lundmark–Melotte.
Part of the dwarf galaxy Wolf–Lundmark–Melotte (WLM) captured by the Spitzer Space Telescope’s Infrared Array Camera (left) and the James Webb Space Telescope’s Near Infrared Camera (right). (NASA, ESA, CSA, IPAC, Kristen McQuinn (RU)/Zolt G. Levay (STScI), Alyssa Pagan (STScI))

As you can see, Webb’s infrared optics and advanced toolset provide a much deeper view that allows individual stars and features to be distinguished. As McQuinn describes:

“We can see countless individual stars of different colors, sizes, temperatures, ages, and evolutionary stages; interesting nebula gas clouds within the galaxy; foreground stars with Webb’s diffraction spikes and background galaxies with neat features, such as tidal tails. It’s a truly spectacular view. “

ERS Program

As McQuinn explains, the main scientific focus of ERS 1334 is to build on previous expertise developed with Spitzer, Hubble, and other space telescopes to learn more about the history of star formation in galaxies.

Specifically, they run deep multiband imaging of three resolved star systems within one Megaparsec (~3,260 light-years) of Earth using Webbs. Near Infrared Camera (NIRCam) and Near Infrared Imaging Slitless Spectrograph (NIRIS).

These include the globular cluster M92ultra-dim dwarf galaxy Draco IIand the star-forming WLM dwarf galaxy.

The population of low-mass stars in the WLM makes it particularly interesting because of their very long lifetimes, meaning that some of the stars seen there today may have formed in the early Universe.

“By determining the properties (such as their age) of these low-mass stars, we can gain insight into what happened in the very distant past,” McQuinn said.

“It’s very complementary to what we’ve learned about the early formation of galaxies. high redshift systemswhere we see galaxies as they were when they first formed.”

Another goal is to use the WLM dwarf galaxy to calibrate the JWST to make sure it can measure the brightness of stars with extreme accuracy, which will enable astronomers to test models of stellar evolution in the near infrared.

McQuinn and colleagues are also developing and testing non-proprietary software that will be made publicly available to measure the brightness of resolved stars imaged with NIRCam.

The results of the ESR projects will be announced before the 2nd Cycle Call for Proposals (27 January 2023).

The James Webb Space Telescope has been in space for less than a year but has already proven invaluable. The breathtaking views of the cosmos it provides include deep-field images, highly accurate observations of galaxies and nebulae, and detailed spectra from extrasolar planet atmospheres.

The scientific breakthroughs he had already allowed were nothing short of groundbreaking. Before his planned 10-year mandate ends (may be extended to 20), some truly paradigm-shifting breakthroughs are expected.

This article was originally published by Universe Today. To read original article.

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