Friday, July 12, 2024

The Lightest Neutron Star

The maximum neutron star mass is an open question in physics that receives more attention than the minimum neutron star mass. But the range of neutron star masses is quite narrow, with roughly a factor of two separating the least massive ones from the most massive ones, and there are theoretical efforts to establish why this is the case.

Supernova theory has struggled to explain the lightest known neutron star candidate with an accurate mass determination, the 1.174M⊙ companion in the eccentric compact binary system J0453+1559. 
To improve the theoretical lower limit for neutron star birth masses, we perform 3D supernova simulations for five stellar models close to the minimum mass for iron core collapse. We obtain a record-low neutron star mass of 1.192M⊙ and a substantial kick of ∼100kms^−1. Given residual uncertainties in stellar evolution, a neutron star origin for the 1.174M⊙ object remains plausible.
Bernhard Müller, Alexander Heger, Jade Powell, "The minimum neutron star mass in neutrino-driven supernova explosions" arXiv:2407.08407 (July 11, 2024).

3 comments:

neo said...

could the lightest known neutron star that is cold be dark matter

andrew said...

@neo No. Among other things, it emits photons, which dark matter, by definition, does not.

neo said...

"Newly formed neutron stars may have surface temperatures of ten million K or more. However, since neutron stars generate no new heat through fusion, they inexorably cool down after their formation. "

I have lightest known primordial neutron star form directly from the big bang and cold now