The search for dark matter is taking a new turn
Neutron stars with high spin rates could be the key to discovering axions, one of the universe's most elusive particles. These hypothetical elementary particles, if detected, could answer some of the cosmos' biggest mysteries, including identifying at least one type of dark matter. The rapid rotation of these neutron stars could trap axions in large enough quantities for detection, offering insights into their nature, mass, etc.
Axions: A potential solution to dark matter mystery
The existence of axions was first proposed by physicists in the 1970s. These particles are believed to interact weakly with other matter, much like neutrinos, making them difficult to detect. If axions fall within a specific mass range, they are expected to behave like dark matter. This could explain the pronounced gravitational effects that cannot be accounted for based solely on the amount of normal matter in the universe.
Axion decay could be key to detection
In theory, axions should easily decay into pairs of photons in the presence of a strong magnetic field, possibly making them visible. The discovery of excess light without an identifiable source near a powerful magnetic field could be a sign of axion decay. Neutron stars have incredibly strong magnetic fields and are the remnants of massive stars that have gone supernova, collapsing into hot, ultra-dense masses.
Pulsars: A potential source of axions
A pulsar is a kind of neutron star that spins at mind-boggling speeds, often at millisecond scales. This rapid rotation amplifies the power of its magnetic field. Physicist Dion Noordhuis from the University of Amsterdam and his team published a study, proposing that these fast-spinning stars could generate a 50-digit number of axions every minute. As these axions escape the star, they would pass through its magnetic field and convert into photons, making the pulsar a tad brighter than anticipated.
Axion clouds are the new frontier in astrophysics
Axions trapped by the star's intense gravity should produce a signal, recent research suggests. Over time, possibly on million-year timescales, axions should accumulate near the pulsar and last the lifetime of the neutron star. This would create a faint layer over the surface of the star. The team's analysis suggests these axion clouds should be common for neutron stars and extremely dense- roughly 20 orders of magnitude higher than local dark matter density.
