• Physics 15, s161
Axions that decay into photons may account for seen gentle that exceeds what’s anticipated to come back from all recognized galaxies.
Should you may change off the Milky Manner’s stars and gaze on the sky with a robust telescope, you’d see the cosmic optical background (COB)—visible-wavelength gentle emitted by every part outdoors our Galaxy. Current research by the New Horizons spacecraft—which, after its Pluto flyby, has been wanting additional afield—have returned probably the most exact measurements of the COB but, displaying it to be brighter than anticipated by an element of two. José Bernal and his colleagues at Johns Hopkins College in Maryland suggest that this extra might be brought on by decaying darkish matter particles referred to as axions . They are saying that their mannequin might be falsified or supported by future observations.
Evaluating COB measurements to predictions supplies a instrument for testing hypotheses in regards to the construction of the Universe. However measuring the COB could be very tough attributable to contamination by diffuse gentle from a lot nearer sources, particularly daylight scattered by interplanetary mud. Observing from the sting of our Photo voltaic System, New Horizons needs to be unaffected by most of this contamination, making the measured extra brightness a instrument for enhancing our understanding of galaxy evolution.
Researchers have attributed the surplus to the glow of unknown galaxies and extra-galactic stars, however Bernal and his colleagues present that it might be defined by the decay of axions if these hypothetical particles exhibit a selected axion-photon coupling energy. In response to the staff’s computations, axions having a mass between 8 and 20 eV may account for the surplus flux in the event that they convert to photons at a fee of
1/1015 years. The researchers say that their work, as effectively exploring a possible rationalization for the COB extra, motivates future searches for darkish matter with these traits.
Rachel Berkowitz is a Corresponding Editor for Physics Journal primarily based in Vancouver, Canada.
- J. L. Bernal et al., “Cosmic optical background extra, darkish matter, and line-intensity mapping,” Phys. Rev. Lett. 129, 231301 (2022).