Galaxy GS-NDG-9422

The galaxy GS-NDG-9422 may easily have gone unnoticed. However, what appears as a faint blur in this NASA/ESA/CSA James Webb Space Telescope image may actually be a groundbreaking discovery that points astronomers on a new path of understanding galaxy evolution in the early Universe.

Detailed information on the galaxy’s chemical makeup, captured by Webb’s NIRSpec (Near-Infrared Spectrograph) instrument, indicates that the light we see in this image is coming from the galaxy’s hot gas, rather than its stars. That is the best explanation astronomers have discovered so far to explain the unexpected features in the light spectrum. They think that the galaxy’s stars are so extremely hot and massive that they are heating up the nebular gas in the galaxy to more than 80 000 degrees Celsius, allowing it to shine even brighter in near-infrared light than the stars themselves.

The authors of a new study on Webb’s observations of the galaxy think GS-NDG-9422 may represent a never-before-seen phase of galaxy evolution in the early Universe, within the first billion years after the Big Bang. Their task now is to see if they can find more galaxies displaying the same features.

[Image description: A black background sprinkled with small, colourful galaxies in orange, blue, and white. On the left, a third of the way down from the top of the image, a very faint dot of a galaxy is outlined with a white square and pulled out in a graphic to be shown magnified. In the pullout square to the right, the galaxy is a hazy white dot edged in orange, with faint blue projections opposite each other at the 11 o’clock and 5 o’clock positions.]

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