Unraveling the Mysteries of Pulsars: Neutron Stars or a Phenomenon Between Black Holes and Neutron Stars?

Is a pulsar a fast-rotating neutron star, or is it a phenomenon existing at the limit between a black hole and a neutron star where the event horizon oscillates? The answer lies within our current understanding of these celestial objects and the principles of physics.

Understanding the Event Horizon

First, it's crucial to understand that there is nothing to oscillate around. The event horizon is not a physical curtain or threshold that can phase back and forth, revealing or hiding the surface of a neutron star. The event horizon is a point of no return, where the gravitational potential of the object is so strong that all trajectories, even those traveling at the speed of light, will bend towards the object and not escape. Once something crosses the event horizon, it cannot come back out.

Neutron Stars: Density and Stability

A neutron star is a dense object where electrons travel at incredible speeds, nearly the speed of light. If more electrons were added, it would be energetically favorable for them to combine with protons to create neutrons. A neutron star is composed of approximately 8 times more neutrons than protons, a stark contrast to most normal matter that has an even split of protons and neutrons. The outward neutron pressure is driven by neutrons trying to remain independent, but if they get too close, the individual quarks cannot distinguish where one neutron ends and the next begins, resulting in a quark-gluon plasma. This is believed to be the state of matter at the core of neutron stars.

Black Holes: Creation and Properties

A black hole forms when the outward pressure of particles not wanting to be in the same space is overcome by the inward pressure of gravity. A singularity forms below a certain point, called the event horizon. As more matter falls in, the event horizon grows, leading to a larger black hole. By the time an entire neutron star collapses into a black hole, it has a much higher mass and size of the event horizon. The process of a neutron star becoming a black hole is so rapid that it can end in a supernova, emitting a shock wave that rips through the outer layers of the star as they rebound off the newly formed black hole.

Pulsars: Rotating Neutron Stars

A pulsar is a rotating neutron star that produces beams of electromagnetic radiation, similar to how auroras are formed on Earth. The beams are created due to the electrons being drawn along the magnetic field lines of the neutron star towards the magnetic poles. The intense gravity accelerates the electrons to incredible speeds, striking the surface of the neutron star at fractions of the speed of light, causing the surface to heat up and emit high-energy photons. This phenomenon can also blast away infalling matter, such as dust and gas.

Formation and Characteristics of Pulsars

The rotation of a pulsar is a result of the conservation of angular momentum. In the nebula where the parent star was born, each particle of hydrogen had some angular momentum, which was conserved as the particles collapsed into a protostar and then further into a spinning star. When the star eventually undergoes nuclear fusion, it continues to spin at the angular momentum it had before. The core of the star, when it reaches the Chandrasekhar limit, undergoes a catastrophic collapse, forming a neutron star with the same angular momentum but in a much smaller space, spinning faster due to the reduced radius.

Conclusion: Neutron Stars as Pulsars

While we may not have 100% certainty, the theory that pulsars are fast-rotating neutron stars is the most compelling explanation based on our current understanding. We cannot physically visit a pulsar to confirm its nature, but the theory aligns perfectly with observations and the laws of physics. Future discoveries and advancements in technology may provide unequivocal evidence or new insights, but for now, the pulsar as a rotating neutron star remains our best explanation for this fascinating phenomenon in the cosmos.