Strange Galactic Signal Coming From the Center of the Galaxy Has Potential New

View of the gamma-ray sky. Credit: NASA/DOE/Fermi LAT Collaboration

Researchers from The

Co-author of the study Associate Professor Roland Crocker said this particular gamma-ray signal — known as the Galactic Center Excess — may actually come from a specific type of rapidly-rotating

“It is based on millisecond pulsars — neutron stars that spin really quickly — around 100 times a second.

“Scientists have previously detected gamma-ray emissions from individual millisecond pulsars in the neighborhood of the solar system, so we know these objects emit gamma-rays. Our model demonstrates that the integrated emission from a whole population of such stars, around 100,000 in number, would produce a signal entirely compatible with the Galactic Center Excess.”

The discovery may mean scientists have to re-think where they look for clues about dark matter.

“The nature of dark matter is entirely unknown, so any potential clues garner a lot of excitement,” Associate Professor Crocker said.

“But our results point to another important source of gamma-ray production.

“For instance, the gamma-ray signal from Andromeda, the next closest large galaxy to our own may be mostly due to millisecond pulsars.”

ANU Masters student Anuj Gautam led the research, which also involved scientists from The Australian Defence Force Academy, University of Canterbury, and University of Tokyo.  

The research has been published in the journal Nature Astronomy.

Reference: “Millisecond pulsars from accretion-induced collapse as the origin of the Galactic Centre gamma-ray excess signal” by Anuj Gautam, Roland M. Crocker, Lilia Ferrario, Ashley J. Ruiter, Harrison Ploeg, Chris Gordon and Oscar Macias, 28 April 2022, Nature Astronomy.
DOI: 10.1038/s41550-022-01658-3