Spinning stars shed new light on strange signal coming from galactic center

Date:

Share post:

Researchers from The Australian National University (ANU) have found an alternative explanation for a mysterious gamma-ray signal coming from the center of the galaxy, which was long claimed as a signature of dark matter. Gamma-rays are the form of electromagnetic radiation with the shortest wavelength and highest energy.

Spinning stars shed new light on strange signal coming from galactic center
View of the gamma-ray sky [Credit: NASA/DOE/Fermi LAT Collaboration]

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 neutron star, the super-dense stellar remnants of some stars much more massive than our sun.

The Galactic Center Excess is an unexpected concentration of gamma-rays emerging from the center of our galaxy that has long puzzled astronomers. “Our work does not throw any doubt on the existence of the signal, but offers another potential source,” Associate Professor Crocker said.

“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.”

The research has been published in Nature Astronomy.

Source: Australian National University [April 28, 2022]

ADVERTISEMENT

spot_img

Related articles

Jupiter’s X-ray auroras pulse independently

Jupiter's intense northern and southern lights pulse independently of each other according to new UCL-led research using ESA's...

The clusters of monster stars that lit up the early universe

The first stars in the Universe were born several hundred million years after the Big Bang, ending a...

Close views show Saturn’s rings in unprecedented detail

Newly released images showcase the incredible closeness with which NASA's Cassini spacecraft, now in its "Ring-Grazing" orbits phase,...

Deep-sea sediments reveal solar system chaos: An advance in dating geologic archives

A day is the time for Earth to make one complete rotation on its axis, a year is...

Hubble’s view of planetary nebula reveals complex structure

NGC 6891 is a bright, asymmetrical planetary nebula in the constellation Delphinus, the Dolphin. This Hubble image reveals...

What does a black hole look like?

At the center of our galaxy lies a swirling, energy-spewing supermassive black hole called Sagittarius A* or Sgr...

US astronomers launch search for alien life on 86 planets

A massive radio telescope in rural West Virginia has begun listening for signs of alien life on 86...

Astronomers find ice and possibly methane on distant dwarf planet

Astronomers at the California Institute of Technology (Caltech) have discovered that the dwarf planet 2007 OR10—nicknamed Snow White—is...