A team of astronomers used an earthquake model to understand the time gaps of pulsars. His results suggest that pulsars may have much weirder interiors than you might think.
Pulsars are perhaps the most accurate timekeepers in the entire Universe. The pulsars themselves are actually rapidly spinning neutron stars. Neutron stars are ultradense balls of atomic matter, usually no more than a few kilometers in diameter, with a mass a few times that of the Sun.
When these neutron stars spin, they emit beams of radiation that draw circles around the sky. If Earth is in one of these circles, we will see a periodic flash of these beams of radiation, creating a pulsar.
Pulsars will maintain a precise rhythm for incredibly long periods of time. But occasionally they are known to crash when they suddenly switch from one spin rate to another.
Astronomers don’t fully understand what causes glitches, but recently a team of researchers has put together a model of how glitches work. The model is based on earthquakes.
Earthquakes have many causes, but one of them is when too much tension and pressure builds up between tectonic plates and the Earth’s crust bends under pressure. This results in an earthquake and a resettlement of material on Earth.
When it comes to neutron stars, their complex interiors can also experience enormous pressures, with components of the neutron star’s material pressing against other parts. If the pressure builds up too much, the neutron star rearranges itself, causing a stellar earthquake and a realignment of its own interior. With the new mass distribution within the neutron star comes a new rotation rate.
The researchers used this earthquake model to try to determine what’s inside neutron stars. The deep cores of neutron stars can be neutrons in a highly exotic state or a more degenerate form of matter made almost entirely of strange quarks.
The researchers found that the model of the neutron star interior that included strange quarks was better able to produce faults through an earthquake mechanism.
Astronomers will need to make more observations to test this idea, but it shows how the observational features of neutron stars can give us hints about their mysterious interiors.
This article was originally published in universe today per Paul M. Sutter. Read the original article here.