Read the following passage about astrophysics carefully. Based on the specific details provided in the text, match each structural component or event of a neutron star (1-4) with the logical inference most strongly supported by the passage.
Pulsars, highly magnetized rotating neutron stars, are renowned for their staggering rotational stability, which rivals that of atomic clocks. However, this uniformity is occasionally punctuated by macroscopic irregularities known as 'glitches'—abrupt, unheralded increases in a pulsar’s spin rate, followed by a gradual relaxation phase lasting days to months. The phenomenon of glitching offers a rare observational window into the obscured interior dynamics of neutron stars.
To account for these sudden spin-ups, astrophysicists have largely adopted a two-component macroscopic model. The star is theorized to consist of a rigid, crystalline crust composed of heavy nuclei and a relativistic electron gas, encapsulating a frictionless inner core of neutron superfluid. Because the core is superfluid, it rotates via quantized vortices. In an idealized state, these vortices migrate outward, allowing the superfluid to decelerate in tandem with the crust, which continuously loses angular momentum to electromagnetic radiation.
However, conditions within the inner crust disrupt this equilibrium. The crustal lattice acts as a pinning landscape, trapping the superfluid vortices and preventing their outward migration. Consequently, while the crust’s rotation slows due to magnetic braking, the pinned superfluid retains its angular momentum, rotating at a comparatively higher velocity. This differential rotation creates an escalating Magnus force between the two components. When the strain reaches a critical threshold, it triggers a catastrophic unpinning of a vast number of vortices. The sudden transfer of angular momentum from the faster-rotating superfluid core to the slower-rotating solid crust manifests externally as a glitch. The subsequent relaxation phase, during which the pulsar’s rotation slowly decays back to its pre-glitch rate, reflects the gradual repinning of vortices and the reestablishment of the differential rotation.
- The crystalline crust prior to a glitchIt rotates at a progressively slower velocity compared to the internal fluid it encapsulates.
- The catastrophic unpinning of vorticesIt immediately reduces the rotational disparity between the neutron star's two primary internal domains.
- The emission of electromagnetic radiationIt acts as the primary external mechanism driving the continuous deceleration of the pulsar's observable exterior.
- The gradual relaxation phaseIt is characterized by a renewed buildup of mechanical strain between the star's internal layers.