NASA's Chandra satellite detects galactic X-rays, hinting at existence of dark matter

Image credit: J.-P. Kneib (Observatoire Midi-Pyrenees, Caltech) et al., ESA, NASA

Boston: Dark matter remains to be one of the most puzzling, yet debatable topics among astrophysicists worldwide for years.

While the theory of dark matter may not look controversial for the majority of physicists and people who have knowledge of the astrophysics, cosmology and/or particle physics, it certainly is currently one of the greatest mysteries in the universe.

However, the search for dark matter and dark energy seems to be just getting more interesting and exciting - with the latest findings from NASA that hint at the existence of dark matter.

Scientists claimed that a small but distinctive X-ray signal detected from the Milky Way galaxy by NASA's Chandra satellite may help prove the existence of dark matter.

Researchers, including those from Massachusetts Institute of Technology (MIT) and Yale Centre for Astronomy and Astrophysics in the US, analysed the energy spectrum of X-rays.

Upon analysing, they found more X-ray photons with a particular energy than would be expected if they were produced only by familiar processes.

Those photons could in fact have been generated by the decay of dark matter particles, say the researchers.

This is not the first time that scientists have seen extra photons with an energy of about 3,500 electronvolts in the spectra recorded by X-ray satellites.

However, previously it was not clear whether the bump, or line, created by the photons in the otherwise smooth spectrum was merely an instrumental artefact, said Kevork Abazajian, from the University of California, Irvine.

The latest research, carried out by Nico Cappelluti at Yale, targets relatively light particles of dark matter, 'BBC News' reported.

Esra Bulbul of the Kavli Institute for Astrophysics and Space Research at the MIT was the first scientist to spot an anomalous line at 3.5 keV, when looking at the X-ray spectra of large numbers of galaxy clusters in 2014.

Scientists believe that dark matter makes up more than 80 per cent of all the mass in the universe.

For years, physicists have been trying to detect particles of dark matter directly by intercepting them using instruments on Earth.

Unlike normal matter and as its name suggests, dark matter does not reflect or emit light, making it extremely hard to spot. It reveals its presence through the gravitational tug it exerts on stars within galaxies.

Hence, researchers have been able to infer the existence of dark matter only from the gravitational effect it seems to have on visible matter.

(With PTI inputs)