Australian National University | 2018 Mar 12
A team of astronomers involving The Australian National University (ANU) has discovered that a mysterious gamma-ray signal from the centre of the Milky Way comes from 10 billion-year-old stars, rather than dark matter as previously thought.
Co-researcher Dr Roland Crocker from ANU said the team had a working hypothesis that the signal was being emitted from thousands of rapidly spinning neutron stars called millisecond pulsars.
“At the distance to the centre of our galaxy, the emission from many thousands of these whirling dense stars could be blending together to imitate the smoothly distributed signal we expect from dark matter,” said Dr Crocker from the ANU Research School of Astronomy and Astrophysics.
“Millisecond pulsars close to the Earth are known to be gamma-ray emitters.”
Dr Crocker said the findings ruled out a provocative theory that dark matter, which is not well understood by scientists, was the origin of the gamma-ray signal. ...
Galactic bulge preferred over dark matter for the Galactic centre gamma-ray excess - Oscar Macias et al
- Nature Astronomy (online 12 Mar 2018) DOI: 10.1038/s41550-018-0414-3 (pdf)