This site has a cross section of neutron star. The iron/electon crust is about 16km thick, and the neutrons are degenerate and superconducting.
Now that is an intersting page, Ring. Might need to see if I can find some more stuff along that line.
As far as degeneracy is concerned neutrons and protons inside the nucleus are arranged in orbitals just as electrons are arranged in orbitals in an atom.
When a degenerate electron gas is formed in a white dwarf these orbitals are destroyed and the electrons only separation is due to the Pauli principle. As the pressure is increased the DeBroglia wavelengths of the electrons is forced to decrease and therefore their energy increases, which is what keeps the white dwarf from collapsing to a neutron star. However when the pressure increases sufficiently the electron motion approaches c and at that point the degeneracy pressure can no longer withstand the compression and the star collapses to a NS.
The same thing occurs with degenerate neutrons which BTW are also fermions
Well, the site mentions how degenerate matter is any instance where particles are actually mashed together, and refers to neutron stars as containing degenerate matter.
Essentially, degenerate matter is in a state where the only force keeping it from collapsing to a singularity is the Pauli Exclusion Principle, I believe.
Note that protons and electrons are also in neutron stars, though not as abundant as neutrons.
This link says
I think the reason is that with more mass, there are more energy levels available, so the neutrons can pack in more tightly.
The cited link also has a diagram of the structure of a neutron star.
I would think that in real life, most of the visible light coming from a neutron star would be radiated by the accretion disk of matter falling onto the star. This would probably be quite hot and have a black-body spectrum.
For computing the orbital period, we can use Kepler’s second law. In solar masses, AU, and years, the general form is (M[sub]1[/sub] + M[sub]2[/sub])P[sup]2[/sup] = a[sup]3[/sup], where the Ms are the masses of the two objects, P is the period, and a is the orbital radius (strictly speaking, the semimajor axis, which is a sort of average radius). Now, suppose we’ve got two neutron stars, just about to merge. Then the distance apart will be just over twice the radius of the stars, or about one ten millionth of an AU. Each one will have about two and a half times the mass of the Sun, for a total mass of 5 solar masses. So this gives us a period of 1.4*10[sup]-11[/sup] years, or a half a millisecond. of course, by this time, there isn’t long to go before final merger.
What you’ll get after the merger will definitely be a black hole. There’s a very narrow range of masses where you can have a neutron star, and probably a narrower range yet for a quark star. Twice the mass of the lighest possible neutron star is easily more than the mass of the heaviest possible quark star.
Degeneracy is used in both a wide and strict sense.
The individual-nuclei-in-an-electron-“soup” degenerate matter of a typical white dwarf core is the strict usage.
Any compression of matter that results in the suppression of electron orbitals is the broad sense, and includes both strict degenerate matter and neutronium, and whatever you want to call a black hole as made of as well.