Tau.Neutrino said:
Researchers discover a new type of matter inside neutron stars
A Finnish research group has found strong evidence for the presence of exotic quark matter inside the cores of the largest neutron stars in existence. They reached this conclusion by combining recent results from theoretical particle and nuclear physics to measurements of gravitational waves from neutron star collisions.
more…
We’ve been waiting for this result for as long as neutron stars have been known to exist. Some ten or so years ago, the first diameter of a neutron star was found, but the diameter was not accurate enough to determine whether most of the star was made of neutrons (hence the name “neutron” stars) or quarks. There was also a lot of speculation back then about whether neutron stars could be made primarily of supersymmetric “dark” matter.
Let’s have a look at the technical article.
> A key factor contributing to the new findings was the emergence of two recent results in observational astrophysics: the measurement of gravitational waves from a neutron star merger and the detection of very massive neutron stars, with masses close to two solar masses.
> In the autumn of 2017, the LIGO and Virgo observatories detected, for the first time, gravitational waves generated by two merging neutron stars. This observation set a rigorous upper limit for a quantity called tidal deformability, which measures the susceptibility of an orbiting star’s structure to the gravitational field of its companion. This result was subsequently used to derive an upper limit for the radii of the colliding neutron stars, which turned out to be roughly 13 km.
https://www.nature.com/articles/s41567-020-0914-9.pdf
> The theory governing the strong nuclear force quantum chromodynamics predicts that at sufficiently high energy densities, hadronic nuclear matter undergoes a deconfinement transition to a new phase of quarks and gluons. Although this has been observed in ultrarelativistic heavy-ion collisions, it is currently an open question whether quark matter exists inside neutron stars
Yeah.
> the presence of quark matter is found to be linked to the behaviour of the speed of sound c in strongly interacting matter. If the conformal bound c^2 ≤ 1/3 is not strongly violated, massive neutron stars are predicted to have sizable quark-matter cores.
So the speed of sound inside neutron stars approaches half the speed of light? That’s fast.
Wow, a 3-D graph with perspective. This actually makes sense. The vertical axis is the speed of sound, an unknown. A second axis is pressure, directly related to star mass. The third axis is gamma, whatever that is. A 1.4 solar mass neutron star is hadronic, ie. made of neutrons. A 2 solar mass maximum mass neutron star is too dense to be composed of neutrons.
The paper is theoretical, but there’s a brief reference to observations in the appendix.
> Comparison with recent mass and radius constraints … In general, this kind of qualitative comparison remains largely inconclusive
Oh dear, not confirmed by observation, yet.
Tau.Neutrino said:
The Rev Dodgson said:
Tau.Neutrino said:
Reckon there’s also a new type of matter in black holes?
You’d better go and have a look.
I’d like to pass a probe through the black holes jets.
From that reverse engineer the jets, figure out what matter it really is.
Unless, unless the jets can be reversed engineered here in a lab somehow…
Could that be possible.?
There’s no real difference between black hole jets and jets from other astrophysical objects. The matter in such jets comes from outside the black hole, just normal matter than has been squeezed, randomised and ejected at high speed. We already have a fair idea what is in these jets, from cosmic rays.
As for reverse-engineering in a lab, that’s a tricky one. It’s not too wrong to say that the jets of matter from a black hole are similar to the jets of matter from particle collisions in the Large Hadron Collider.
