James Webb Telescope shows spiral galaxy IC 5332 in unprecedented details

Spiral galaxy IC 5332 image, taken by Webb's MIRI instrument. Credit: ESA/Webb, NASA & CSA, J. Lee and the PHANGS-JWST and PHANGS-HST Teams

September 27, 2022

Located at a distance of around 29-million-light-year, intermediate spiral galaxy called IC 5332, in the constellation Sculptor is remarkably faint and exquisitely symmetrical. From Earth, it appears to be almost face on. It is classified because of its wide spiral arms and tiny central bulge. It lies in the direction of the galactic south pole.

This Webb image displays the spiral galaxy in unprecedented detail. Over 29 million light-years away from Earth, IC 5332 is a little bigger than the Milky Way with a diameter of about 66 000 light-years. We may observe the symmetrical sweep of its spiral arms since it is notable for being almost exactly face-on to Earth.

Only MIRI, which operates in the 5 µm – 28 µm wavelength range, is sensitive to the mid-infrared area of the electromagnetic spectrum; all other Webb instruments function in the near-infrared. The first sensor to produce mid-infrared images clear enough to be easily matched to Hubble's view at shorter wavelengths is MIRI, which was developed jointly by the ESA and NASA.

One of MIRI's most noteworthy characteristics is that it runs at a frigid temperature of -266 °C, 33 °C below the rest of the observatory. As a result, MIRI runs in a space that is only 7 °C above absolute zero, which is the lowest temperature that is feasible given the rules of thermodynamics. Because MIRI's highly specialized detectors must operate in this chilly environment, it features a specialized active cooling system to make sure that the detectors are maintained at the proper temperature.

It is important to note how difficult it is to collect observations in the electromagnetic spectrum's mid-infrared range. From Earth, it is extremely challenging to monitor the mid-infrared because so much of it is absorbed by the atmosphere, and the heat from the atmosphere makes things much more challenging. Due to Hubble's insufficiently cool mirrors, which would have caused infrared radiation from the mirrors to dominate any attempted observations, Hubble was unable to view the mid-infrared area. This amazing image shows the extra care taken to guarantee that MIRI's detectors have the cold environment required to function properly.

Source: ESA