Just days after the first formal release of their first images, scientists using the new James Webb Space Telescope (JWST) have released some impressive new images of spiral galaxies.
A Danish scientist, Gabriel Brammer, has processed new public data from the James Webb Space Telescope launched last December and has obtained this incredible image of the galaxy NGC 628 , known as the Fan Galaxy.
What we see is the center of this galaxy, imaged by a researcher who downloaded James Webb’s data available to the general public.
an extraordinary image
Webb took the image of NGC 628 on July 17 and sent the data back to Earth, where it is stored in the Barbara Mikulski Archive for Space Telescopes (MAST), which is open to the public.
Like a vortex from Doctor Who, the image is a composite of three data sets at different wavelengths taken by James Webb’s team of mid-infrared instruments. Gabriel Brammer of the University of Copenhagen in Denmark, who is not part of the team, downloaded the data and translated each of the infrared wavelengths to red, green and blue before combining them to produce an image.
The swirling purple arms 32 million light-years from Earth, however, aren’t really this stunning shade of purple.
Here we see NGC 628 which looks like our own Milky Way as seen from above the galactic plane. The image’s distinctive violet appearance is due to the unique chemical composition of this galaxy’s dust clouds, which are composed primarily of large molecules called polycyclic aromatic hydrocarbons.
As is usual in astronomy, the color image is made up of three separate exposures obtained through filters, in this case centered at 7.7, 10 and 11.3 microns.
The spiral arms of NGC 628 have been photographed before, but the Hubble Space Telescope took them in visible light. Brammer downloaded processed raw data and then compiled the views from three of MITI’s nine filters to produce the bright purple galaxy. Thus, the image that we can see in this article shows a purple tint caused by the emission of polycyclic aromatic hydrocarbon molecules, a hydrocarbon that is seen brightly through Webb’s blue and red filters.
The wavelengths were only captured by JWST on Sunday, so astronomers haven’t had a chance to analyze the findings yet. However, some scientists have already noted in Brammer’s social media posts of the image that the empty center is different from what visual images of the galaxy show, and could indicate interesting physical processes.
As the author of the image himself has commented, composing it from the Webb data “was amazingly simple. Although the telescope is a great resource, we have also made similar improvements to the technology to process the data and distribute it so that anyone from astronomers to non-experts can explore the data in this way,” says Brammer.
