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| Researchers traced light that was emitted by the bright white elliptical galaxy on the left through the spiral galaxy at right. As a result, they were able to identify the effects of interstellar dust in the spiral galaxy. Webb’s near-infrared data also show us the galaxy’s longer, extremely dusty spiral arms in far more detail, giving them an appearance of overlapping with the central bulge of the bright white elliptical galaxy on the left, though the pair are not interacting. In this image, green, yellow, and red were assigned to Webb’s near-infrared data taken in 0.9, 1.5, and 3.56 microns (F090W, F150W, and F356W respectively). Blue was assigned to two Hubble filters, ultraviolet data taken in 0.34 microns (F336W) and visible light in 0.61 microns (F606W). Credit: NASA, ESA, CSA, Rogier Windhorst (ASU), William Keel (University of Alabama), Stuart Wyithe (University of Melbourne), JWST PEARLS Team |
This article showcases data from Webb science in progress that has not yet been peer-reviewed. Rogier Windhorst, an interdisciplinary scientist at Webb, and his colleagues describe their findings here. By merging data from NASA's James Webb Space Telescope with NASA's Hubble Space Telescope, we received more than we bargained for! Webb's new data allowed us to follow the light emitted by the brilliant white elliptical galaxy on the left into the twisting spiral galaxy on the right, identifying the impacts of interstellar dust in the spiral galaxy. This picture of galaxy pair VV 191 combines Webb's near-infrared light with Hubble's ultraviolet and visible light.
Webb's near-infrared observations also provide significantly more detail about the galaxy's longer, highly dusty spiral arms, which appear to overlap with the central bulge of the brilliant white elliptical galaxy on the left. Although the two foreground galaxies are astronomically close, they are not actively interacting. VV 191 is the most recent addition to a limited group of galaxies that allow researchers like us to compare the features of galactic dust directly. This target was chosen among over 2,000 superimposed galaxy pairings discovered by Galaxy Zoo citizen scientists.
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| Above the white elliptical galaxy at left, a faint red arc appears in the inset at 10 o'clock. This is a very distant galaxy whose appearance is warped. Its light is bent by the gravity of the elliptical foreground galaxy. Plus, its appearance is duplicated. The stretched red arc is warped where it reappears—as a dot—at 4 o'clock. In this image, green, yellow, and red were assigned to Webb's near-infrared data taken in 0.9, 1.5, and 3.56 microns (F090W, F150W, and F356W respectively). Blue was assigned to two Hubble filters, ultraviolet data taken in 0.34 microns (F336W) and visible light in 0.61 microns (F606W). Credit: NASA, ESA, CSA, Rogier Windhorst (ASU), William Keel (University of Alabama), Stuart Wyithe (University of Melbourne), JWST PEARLS Team |
Understanding where dust exists in galaxies is critical because dust alters the brightness and hues seen in photographs of galaxies. Because dust grains play a role in the creation of new stars and planets, scientists are always looking for evidence of their presence for future research.
The photograph contains a second revelation that is more easily overlooked. Look at the white elliptical galaxy on the left. At 10 o'clock, a tiny red arc appears in the inset. This is a very distant galaxy whose light is distorted by the gravity of the elliptical foreground galaxy, resulting in a duplicated appearance. The extended red arc gets twisted, reappearing as a dot around 4 p.m. These pictures of the lensed galaxy are so dim and red that Hubble missed them, yet they are apparent in Webb's near-infrared image. Simulations of gravitationally lensed galaxies like this one help us figure out how much mass is in individual stars and how much dark matter is in the galaxy's center.
This view of VV 191 shows new galaxies further and deeper in the background, as do many Webb photographs. Two patchy spirals to the top left of the elliptical galaxy appear to be the same size but in quite different hues. One is probably very dusty, and the other is quite far away, but we or other astronomers need to acquire data known as spectra to figure out which is which.
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