Webb's First Deep Field (NIRISS Emission Spectra) : 無料・フリー素材/写真
Webb's First Deep Field (NIRISS Emission Spectra) / James Webb Space Telescope
| ライセンス | クリエイティブ・コモンズ 表示 2.1 |
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| 説明 | Want to go on a galactic treasure hunt? Data known as spectra from NASA’s Webb Telescope make it easy to find – and match up – cosmic prizes!At far left is a near-infrared image of galaxy cluster SMACS 0723. A group of massive galaxies below and to the right of the bright central star have distorted, magnified, and mirrored many galaxies in this field.By quickly examining the image at left by eye, it becomes clearer that one arc may be made up of two similar-looking galaxies. Their bright central regions match, despite their stretched appearances. These may be lensed galaxies – one galaxy that is mirrored in a second location. Are they the same? Researchers can’t be sure from the image alone – more data are needed to confirm a match.Scientists do this by gathering spectra, which spread light out so they can fully examine an object’s makeup. Webb’s Near-Infrared Imager and Slitless Spectrograph (NIRISS), which gathers spectra of every object in any field it observes, was pointed at the galaxy cluster to gather more detail. A segment of the NIRISS grism image (an instrument that has a grating, or stair steps, on a prism), at center, shows how ionized oxygen and atomic hydrogen emission lines are distributed along the arc.Next, the spectra from each of these two galaxies were plotted as graphs, shown at right, to reveal their compositions. The graphs, known as spectra, match, which indicates that these arcs are mirror images of the same galaxy. Webb’s spectra from NIRISS also quickly proved that light from both galaxies was emitted 9.3 billion years ago, further confirming they are one and the same.Using Webb’s NIRISS is like opening a treasure chest overflowing with spectra. For example, this instrument can disperse the spectra along the image vertically and horizontally. Researchers can use both modes to untangle which lines match each source.Every object’s image can be transformed into spectra like the two shown above. So even if researchers aren’t intending to study a particular galaxy in the field, they may make a surprise discovery.For a full array of Webb’s first images and spectra, including downloadable files, please visit: webbtelescope.org/news/first-images NIRISS was contributed by the Canadian Space Agency (CSA). The instrument was designed and built by Honeywell in collaboration with the Université de Montréal and the National Research Council Canada.Credits:IMAGE: NASA, ESA, CSA, STScI Image descriptionInfographic titled “Galaxy Cluster SMACS 0723, Webb Spectra Confirm Two Arcs Are the Same Galaxy; NIRISS Imaging, NIRIS Grism, and NIRISS Wide Field Slitless Spectroscopy.” At far left is a large NIRISS image, with two long, arced galaxies toward the center. In the middle is a NIRISS Grism image that shows the light of every object in this segment of the galaxy field, spread out horizontally. The right side shows two line graphs. The brightnesses at each wavelength of the two long, arced galaxies are plotted in two line graphs. The graphs show that the peaks for hydrogen and oxygen occur at the same wavelengths for both galaxies. |
| 撮影日 | 2022-07-12 10:57:55 |
| 撮影者 | James Webb Space Telescope , Greenbelt, MD, USA |
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