James Webb takes a closer look at the ‘WLM’ dwarf galaxy

What is a dwarf galaxy?🇧🇷

A dwarf planet, represented by Pluto, does not fit the definition of a planet, but is a smaller planet-like celestial body. That is, it must have sufficient mass to maintain its circular shape while revolving around the sun and must not be a satellite of another planet. However, it must be a celestial body that cannot absorb the other celestial bodies around its orbit. Of course, it is very difficult to determine the size, mass and radius numerically because the exact numbers depend on the astrophysical properties of the celestial body.

On the other hand, dwarf galaxies are galaxies that meet the definition of a galaxy but are small, such as the small size of a dwarf planet. Galaxies usually consist of billions of stars, and these galaxies have very few stars compared to our galaxy. Due to its small size, mass, and gravity, it is prone to interactions with the larger galaxies around it.

For example, they have been observed to be distorted or destroyed when neighboring spiral galaxies attract them. Because of the above, dwarf galaxies are recognized as very important objects in the evolution of galaxies and the universe. Most dwarf galaxies are known to be associated with dark matter, but new types of dwarf galaxies have been discovered recently.

dwarf galaxy WLMIn second place filmed The mosques network space telescope

Specializing in near infrared light, the James Webb Space Telescope (JWST) is showing off one stunning image after another. Professor Christine McEwen of Rutgers University in New Jersey, USA, is among the 1,334 astronomers leading the Webb Early Release Science (ERS) programme, which focuses on observations of correctly resolved star clusters with James Webb’s sensitive resolution. , including many stars within the Wolf-Lundmark-Melotte Galaxy (WLM).

This revealed some observations of the Wolf-Lundmark-Melotte Dwarf Galaxy (WLM), attesting to James Webb’s exceptional precision. A comparison with images from the Spitzer Space Telescope, predecessor to James Webb, shows just how far human astronomy has come in just 20 years. Although the Spitzer Space Telescope has been widely used in general fields of observation due to its relatively small aperture and narrow wavelength range, opening up a new horizon for infrared astronomy, James Webb can see that it is much easier to observe more specific objects.

Spitzer space telescope with the results of observation to compare

The image on the left was taken by the IRAC instrument on the Spitzer Space Telescope, and the image on the right was taken by the NIRCam instrument on the James Webb Space Telescope. As a result of observations with the Spitzer Space Telescope, many galaxies and stars appear blurry against a black background.

Most celestial bodies are white, but some are blue or red. However, since most of them do not show complete accuracy, exact identification of celestial bodies is impossible. The Spitzer Space Telescope does not have good resolution due to the small size of the primary mirror (0.85m in diameter), but it is an ideal telescope for identifying cold objects in the universe because the observing wavelength (3.6~160μm) is infrared. In addition, although the average life expectancy was 6 years, it is a grateful telescope that has been continuously observing the infrared universe for more than 16 years and diligently investigating the mysteries of the universe.

However, the resolution of James Webb is not comparable to that of the Spitzer Space Telescope because the primary mirror is much larger and the observed wavelength is shorter (generally shorter wavelengths and larger primary mirrors show good resolution). Observations with the Spitzer Space Telescope have completely resolved most unknown objects, revealing thousands of clearly distinguishable objects in a variety of colors, sizes, shapes, and brightnesses. Most celestial bodies appear dark orange, blue, and white, and these are the stars that make up the WLM galaxy.

In particular, since most of the celestial bodies that can be seen in the James Webb images are celestial bodies that did not appear in the observational images of the Spitzer Space Telescope, it seems that the James Webb Space Telescope can be estimated as a huge amount of capital and effort. 🇧🇷Go see high resolution comparison photos🇧🇷

dwarf galaxy WLMhe is Because This will be fun🇧🇷

WLM is a dwarf galaxy in the galactic neighborhood. Although it is very close to our galaxy (about 3 million light-years from Earth, but a light-year is the distance light travels in one year, about 9.46 trillion km), it is a relatively isolated galaxy.

Until now, the astronomy community has not considered the WLM to interact with other systems, making it an ideal object for testing theories of galaxy formation and evolution. Many other nearby galaxies, if not dwarf galaxies, show traces of evolution through interactions with nearby galaxies. 🇧🇷Zoom in Go watch the video🇧🇷

© NASA, ESA, CSA, STScI, Kristen McQuinn / Rutgers University, Image processing: Alyssa Pagan, Zulte Levay / STScI

Another interesting point is that the gas that made up the galaxy above is similar to the gas that made up the galaxy in the early universe. That is, elements heavier than hydrogen and helium are less abundant than in other galaxies. This is likely because the galaxies have lost many components of the galactic wind.

The stars in the WLM formed relatively recently, and this is expected to be due to some material being ejected from smaller galaxies when nearby massive stars explode, such as supernovae. As a result, the WLM galaxy is expected to provide answers to the question of how stars formed and evolved in young galaxies in the distant past. 🇧🇷Go see high-resolution photos of JWST🇧🇷

Low-mass stars usually live billions of years or more. This indicates that some of the stars visible in the WLM formed in the early universe. By examining the lives and properties of these low-mass stars, we can gain insight into what happened in the very distant past. In particular, looking at very high redshift galaxies that retain their appearance when they first formed in the puzzle of early galaxy formation.

Professor McQueen’s team observed the galaxy above using the Hubble Space Telescope. By comparing the two images above, we are developing an instrument that can measure the brightness of stars more precisely. With this, the model of stellar evolution is expected to be completed.

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