The first observations made by the James Webb Space Telescope were released live on NASA TV on July 12 at 11:30 PM Korean time (July 12, 10:30 AM EST). There are five publicly available high-resolution images and spectral spectra: the SCAMS 0723 galaxy cluster, the hot gas exoplanet WASP-96b (spectral spectrum), the NGC 3132 nebula known as the Southern Ring Nebula, Stephan’s Quintet, and the Carina Nebula. The edge of NGC 3324 includes the ‘Cosmic Cliff’. (See related article – ‘James Webb Space Telescope Reveals First Observation Results’)
In the James Webb Space Telescope Observation Interpretation series, we dig through high-resolution images one by one to find out what the pictures mean and what James Webb’s plans for the future of celestial bodies are. James Webb’s fifth image is a group of five galaxies called Stephan’s Quintet, which became a hot topic because it was possible to grasp hints regarding the evolutionary process of galaxies that had not been seen before.
Stephen’s Quintet
In 1877, French astronomer Édouard Stephan discovered a group of galaxies in the constellation Pegasus (NGC 7317, NGC 7318a, NGC 7318b, NGC 7319, and NGC 7320c) at the Marseille Observatory. Later, the Group of galaxies (a group of less than 50 galaxies bound by each other’s gravity) was nicknamed “Stephan’s Quintet”, and the Hickson Compact Group 92 (HCG 92). also known as The above group of galaxies has a very severe redshift of 790-6747 km/s, with an apparent magnitude of +13.9 to +16.7.
From left to right, the NGC 7320c galaxy, the NGC 7319 galaxy, the NGC 7318b (UGC 12100) galaxy, the NGC 7318a (UGC 12099) galaxy, and the NGC 7317 galaxy are located. © NASA, ESA, and the Hubble SM4 ERO Team
The above picture taken with the Hubble Space Telescope alone is so beautiful and wonderful that you can see the universe. From left to right, NGC 7320c, NGC 7319, NGC 7318b (UGC 12100), NGC 7318a (UGC 12099), and NGC 7317 are located. NGC 7317 and NGC 7318a are ellipsoidal in shape. It is an elliptical galaxy and the rest of the galaxies are in the form of barred spiral galaxies.
The interesting thing regarding the group above is that, although nicknamed the quintet, there are actually only 4 galaxies in the group (NGC 7317, NGC 7318a, NGC 7318b, and NGC 7319). These four galaxies are regarding 290 million light-years away. The rest of the NGC 7320c galaxies coincidentally appear to be together because they have the same line of sight from Earth, and are approximately 40 million light-years from Earth.
The apparent size of the cluster above is regarding one-fifth the diameter of the moon. Also, this group of galaxies is relatively close compared to other galaxies, usually billions of light-years away. Because of this proximity, they are a group of galaxies that can be studied in more detail by merging and interacting with galaxies, which are very important for galactic evolution. These interactions allow detailed observations of how galaxies trigger each other’s star formation and how gases are perturbed. Therefore, astronomers call this group of galaxies a ‘fantastic laboratory’ for galaxy study. What new information might be revealed by observing the group of galaxies above with the unprecedented resolution of the James Webb Space Telescope?
Stefan’s quintet observed with mid-infrared light
The picture below is an image of Stephen’s quintet taken with the James Webb Space Telescope’s MIRI (Middle Infrared Instrument). Note that the NGC 7317 galaxy is not included in the above image. The north and east compass arrows show the direction of the image when viewed from below, and the direction when viewed from above should be reversed. The scale bar is expressed in light years, the distance light travels in one year, and it takes light regarding 100,000 years to travel the length of the scale bar. For reference, one light-year is equal to 9.46 trillion km (or regarding 5.88 trillion miles). This shows that the object shown in the image above is regarding 370,000 light-years across (since the NGC 7317 galaxy is not included).
Stefan’s quintet observed in mid-infrared light, clockwise from left, NGC 7320c, NGC 7319, NGC 7318b, and NGC 7318a are visible. © JWST/NASA, ESA, CSA, STScI
The above image shows the invisible mid-infrared wavelength converted into visible light color. The letters listed in different colors below the picture indicate the MIRI filter that was used to collect the light. The color of each filter name is the color of visible light used to represent the mid-infrared passing through that filter, and is a composite of individual exposures. (Go to high-resolution photo)
Stefan’s quintet observed with near-infrared and mid-infrared
The picture below is an image of Stephen’s quintet taken with the James Webb Space Telescope’s NIRCam (Near-InfraRed Camera) and MIRI (Mid-InfraRed Instrument). For reference, the image above includes the galaxy NGC 7317, providing a complete picture of the Stefan quintet. Again, the north and east compass arrows show the direction of the image when viewed from below, and the scale bar shows that the size of the celestial body displayed in the image above is regarding 62,000 light-years.
From left to right, the NGC 7320c galaxy, the NGC 7319 galaxy, the NGC 7318b galaxy, the NGC 7318a galaxy, and the NGC 7317 galaxy are visible. © JWST/NASA, ESA, CSA, STScI
The image above shows the invisible near-infrared and mid-infrared wavelengths converted into visible light colors. The letters listed in different colors below the picture represent the NIRCam and MIRI filters used to collect the light. The color of each filter name is the color of visible light used to indicate the near and mid infrared passing through that filter, and is a composite of individual exposures. The picture above is an image that contains over 150 million pixels and is a composite of over 1,000 individual image files.
The above photograph of the Milky Way seen through the eyes of James Webb is not surprising or even terrifying. Countless galaxies and stars have been photographed in the background of the group, and numerous objects around the group have been revealed that have never been seen with any space telescope. Thousands of celestial backgrounds reminiscent of Hubble’s Deep Fields are enough to excite the public. Bright clusters of millions of young stars and regions of new star formation have also been photographed, and the galactic group is one of the clearest astrophotography ever taken.
In the photo above, two of the three MIRI filters were used, and through this, hot gas and dust structures in the galaxy, shock waves between galaxies, and their interactions are well exposed. In particular, the MIRI image of the group of galaxies captures a huge shock wave as the NGC 7318B galaxy passes through the cluster, which surrounds the central pair of galaxies and appears red and gold.
In addition, in the group of galaxies observed using NIRCam, the bright nucleus of the galaxy as well as several stars were captured in the NGC 7320 galaxy, which is the leftmost and closest galaxy to us. In particular, aging and dying stars have a red dot-like appearance. (Go to high-resolution photo)
→ Continued on the next page on paper. (View related article – ‘How the Galaxy Evolution Proceeds Part 2’)
“Interpretation of First Observations of the James Webb Space Telescope” Series Guide
About the Deep Field: James Webb’s Deep Field Was So Beautiful – Part 1
About the Deep Field: James Webb’s Deep Field Was So Beautiful – Part 2
Exoplanet Related: Discovery of Water in the Atmosphere of a Hot Gas Planet
The Death of a Star: A Closer Look Around a Dying Star – Part 1
The Death of a Star: A Closer Look Around a Dying Star – Part 2
Star Birth Related: Carina Nebula’s “Cosmic Cliffs” Revealed in Detail
Galaxy Related: How galaxies evolve – Part 1
Galaxy Related: How galaxies evolve – Part 2
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