James Webb showed eye-catching details of a neighboring galaxy
The James Webb Space Telescope looked at a neighboring dwarf galaxy near the Milky Way, revealing its massive star population.
Program The James Webb Space Telescope's "Early Science Release" (ERS), which launched on July 12, 2022, has proven to be a treasure trove of scientific discoveries and advances.
ERS 1334 of these is a term that deals with the study of "discrete stellar populations" (RST). This classification refers to large groups of stars that are close enough to us that individual stars can be seen, but far enough that telescopes can see many of them in the field of view at once.
A good example is the dwarf galaxy "Wolf-Lundmark-Melotte" (Wolf-Lundmark-Melotte) or WLM in the neighborhood of the Milky Way, which, according to James Webb's observations, has not interacted with other galaxies in the past, and is a suitable case for investigating theories of formation and It is the evolution of galaxies.
Characteristics of WLM
The WLM galaxy is approximately 3 million light-years away from Earth, and although it is considered very close in terms of astronomy, it is relatively isolated, and astronomers have come to the conclusion that It has not interacted with other objects in the past.
However, other neighboring dwarf galaxies are usually gravitationally involved with the Milky Way and are merging with it. Such a state makes them more difficult to study because their populations of stars and gas clouds cannot be completely distinguished from that of the Milky Way.
The WLM galaxy as seen by the European Very Large Telescope
Credit: ESO
The WLM is also heavier in elements than hydrogen And helium, which was very common in the early universe, is very empty. Elements such as carbon, oxygen, silicon and iron formed in the core of early stars and dispersed in the universe with their explosion during supernova events.
This galaxy has also experienced the formation of stars throughout its history and the force The explosions gradually pushed these elements out. This process is known as "galactic winds" and has been seen in small, low-mass galaxies.
James Webb's View
Now new Webb images provide the clearest view yet of the WLM, allowing Provides discrimination of individual stars and structures. Before this, the "Infrared Array Camera" (IAC) instrument in the "Spitzer Space Telescope" (SST) had also observed this galaxy, but compared to James Webb, it had much less resolution.
Kristen McQueen "(Kristen McQuinn), assistant professor of astrophysics at Rutgers University said in this regard: "We can see countless numbers of stars with colors, sizes, temperatures, ages and in different stages of evolution; The galaxy's interesting nebular gas clouds, foreground stars with James Webb diffraction structures, and background galaxies with regular features such as the eddy tail are clearly visible in this beautiful image.
ERS Program 1334
Underlying the development of space telescopes including Spitzer and Hubble, the main focus of the ERS 1334 program is studying the star formation history of galaxies. Using the Near-Infrared Camera (NIRCam) and the Near-Infrared Imaging Slitless Spectrometer (NIRISS) on board the James Webb, researchers are engaged in multi-band deep imaging of three separate star systems within a megaparsec (about 3,260,000 light-years) from are the earth.
Comparison of James Webb and Spitzer image From the WLM galaxy
Credit: NASA, ESA, CSA, STScI, and Kristen McQuinn (Rutgers University). IMAGE PROCESSING: Alyssa Pagan (STScI).
These systems include the globular cluster M92, the ultra-faint dwarf galaxy Draco II, and the star-forming dwarf galaxy WLM. The WLM population of low-mass stars in particular makes it interesting. Such stars are very long-lived, and some of the stars seen there today may have formed early in the universe. According to McQueen, "by determining the properties of these low-mass stars, such as their age, we can gain an understanding of what happened in the very distant past."
This method complements what can be seen by looking at systems. whose light is strongly red-shifted and shows galaxies as they form.
Another purpose of using the WLM dwarf galaxy is to calibrate James Webb for its reliability to measure the brightness of stars with high precision. Check above. This work will help astronomers better test models of stellar evolution in the near-infrared spectrum.
McQueen and his colleagues are also developing and testing open-source, public software to measure the brightness of discrete stars that Nirkam photographed them. The results of this project are expected before the call for the cycle The second science of James Webb, which will start on January 27, 2023 (Behan 7, 1401), will be published.
James Webb has been in space for less than a year, but he has completely proven his abilities. Stunning views of the cosmos, including deep-field images, highly detailed observations of galaxies and nebulae, and detailed spectroscopy of exoplanet atmospheres are part of the work of this powerful scientific instrument. It is expected that we will see other amazing discoveries by it before the end of its planned 10-year life.
Source: Science Alert