Shining like a brilliant beacon amidst a sea of galaxies, Arp 220 lights up the night sky in this view from the NASA/ESA/CSA James Webb Space Telescope https://esawebb.org/images/arp220a/

Source: Webb captures the spectacular galactic merger Arp 220

Shining like a brilliant beacon amidst a sea of galaxies, Arp 220 lights up the night sky in this view from the NASA/ESA/CSA James Webb Space Telescope. Actually two spiral galaxies in the process of merging, Arp 220 glows brightest in infrared light, making it an ideal target for Webb. It is an ultra-luminous infrared galaxy (ULIRG) with a luminosity of more than a trillion suns. In comparison, our Milky Way galaxy has a much more modest luminosity of about ten billion suns.

Located 250 million light-years away in the constellation of Serpens, the Serpent, Arp 220 is the 220th object in Halton Arp’s Atlas of Peculiar Galaxies. It is the nearest ULIRG and the brightest of the three galactic mergers closest to Earth.

The collision of the two spiral galaxies began about 700 million years ago. It sparked an enormous burst of star formation. About 200 huge star clusters reside in a packed, dusty region about 5,000 light-years across (about 5 percent of the Milky Way’s diameter). The amount of gas in this tiny region is equal to all of the gas in the entire Milky Way galaxy.

By now most repeat-enjoyers of JWST's images are familiar with the pointy "star" patterns that appear at bright compact objects (generally individual bright stars) in JWST images produced by diffraction from various components of JWST's optics, including the hexagonal outline of JWST's primary and the spider mount for the secondary (as well as some internal optical elements on spider mounts sometimes I think).

However the center of the object Arp 220 is a compact but still somewhat extended source of light (merging galaxies) and so the "star" diffraction pattern is fuzzy and the "arms" are pretty thick.

This object seems to be a good candidate to try to deconvolve the image using the now very well characterized diffraction pattern of the telescope as the deconvolution kernel.

Question: Is there a standard deconvolution procedure to remove JWST's diffraction pattern yet? If so, would Arp 220 be a good candidate on which to try it?


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    $\begingroup$ xkcd.com/2762 $\endgroup$ Apr 18, 2023 at 14:10
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    $\begingroup$ aanda.org/articles/aa/full_html/2016/05/aa24003-14/… maybe? I'm not terribly familiar with this kind of stuff XD $\endgroup$
    – DialFrost
    Jun 14, 2023 at 2:13
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    $\begingroup$ @DialFrost that's an interesting paper about a method for deconvolution, but here I'm asking about JWST with it's very spiky - pointy - large point spread function (PSF) due to its' hexagonal aperture with sub hexagons, central obstruction and three secondary support arms - one of which adds two more spikes. It's a really challenging PSF to deconvolute, so I think it will need a more elaborate procedure tailored for JWST images. $\endgroup$
    – uhoh
    Jun 14, 2023 at 4:31
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    $\begingroup$ Oh, my bad sorry, I'll keep looking $\endgroup$
    – DialFrost
    Jun 14, 2023 at 12:58


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