JWST Looks Within for Dark Matter
Since its launch in 2021, the JWST has observed not just galaxies at the edge of the visible Universe but also our nearest stellar neighbor, Proxima Centauri. Now Peizhi Du at the University of Science and Technology of China and colleagues have used the JWST to look for objects that are even closer. By analyzing ostensibly blank calibration images, the team sought signs of dark matter within the telescope itself [1]. Finding none, the researchers put constraints on the existence of dark matter that interacts strongly with ordinary matter.
Du and colleagues considered one proposed type of dark matter that interacts with electrically charged particles. The strength of this interaction is orders of magnitude feebler than that of electromagnetism but is still sufficiently large that it would hinder the particles’ passage through Earth’s atmosphere. Such dark matter is therefore expected to be especially hard to spot using typical ground-based experiments. Instead, space-based instruments offer a promising alternative.
The team analyzed images acquired when JWST’s near-infrared spectrograph was covered. These images were obtained so that researchers could characterize the instrument’s noise. Even so, although the sensor was protected from external photons, pixels could still record cosmic rays and internally generated radiation. Du and colleagues filtered out those events in the hope of finding a residual signal caused by strongly interacting dark matter. The absence of such a signal implies that this form of dark matter contributes no more than 0.4% to the Universe’s total.
–Marric Stephens
Marric Stephens is a Corresponding Editor for Physics Magazine based in Bristol, UK.
References
- P. Du et al., “Direct constraints on strongly interacting dark matter from the James Webb Space Telescope,” Phys. Rev. Lett. 135, 051002 (2025).