相关论文: Cooling binary neutron star remnants via nucleon-n…
We study the impact of finite-temperature effects in numerical-relativity simulations of binary neutron star mergers with microphysical equations of state and neutrino transport in which we vary the effective nucleon masses in a controlled…
Axion dark matter can form stable, self-gravitating, and coherent configurations known as axion stars, which are rendered unstable above a critical mass by the Chern-Simons coupling to electromagnetism. We study, using numerical relativity,…
Compact stellar objects like supernovae and neutron stars are believed to cool by emitting axions predominantly via axion bremsstrahlung ($NN \to NNa$), pion conversion ($\pi^- p^+ \to N a$) and photo-production ($\gamma N \to N a$). In…
Ultralight bosons such as axions and dark photons are well-motivated hypothetical particles, whose couplings to ordinary matter can be effectively constrained by stellar cooling. Limits on these interactions can be obtained by demanding…
We reconsider the problem of neutrino pair bremsstrahlung emission originating from the electromagnetic collisions of charged particles in nucleonic ($npe\mu$) neutron star cores. Two limiting cases are considered: (i) protons are in the…
The cores of dense stars are a powerful laboratory for studying feebly coupled particles such as axions. Some of the strongest constraints on axionlike particles and their couplings to ordinary matter derive from considerations of stellar…
The origin of cool-core (CC) and non-cool-core (NCC) dichotomy of galaxy clusters remains uncertain. Previous simulations have found that cluster mergers are effective in destroying CCs but fail to prevent overcooling in cluster cores when…
The high quiescent X-ray luminosity observed in some magnetars is widely attributed to the decay and evolution of their ultra-strong magnetic fields. Several dissipation mechanisms have been proposed, each operating with different…
We explore, using an exact cooling code, the thermal evolution of a neutron star undergoing episodes of intense accretion, alternated by long periods of quiescence (e.g. Soft X-Ray Transients). We find that the soft component of the…
We discuss axion dark matter detection via two mechanisms: spontaneous decays and resonant conversion in neutron star magnetospheres. For decays, we show that the brightness temperature signal, rather than flux, is a less ambiguous measure…
We analyse the cooling of white dwarfs in the globular cluster 47 Tucanae to look for evidence of axion emission affecting the rate of white dwarf cooling. If axions exist and couple to electrons, then axions could be produced at an…
Neutrino and axion production in neutron stars occurs mainly as bremsstrahlung from nucleon-nucleon (NN) scattering. The energy radiated via neutrinos or axions is typically very small compared to other scales in the two-nucleon system. The…
Core-collapse supernovae provide a unique opportunity to probe axions because they can be a copious source of the particles. It has recently been proposed that axion helioscopes can be used for the direct search for supernova axions if a…
We present a systematic study of QCD axion production in environments with finite baryon density and temperature, implying significant changes to axion phenomenology. Within heavy baryon chiral perturbation theory, we derive the effective…
The most efficient axion production mechanism in a supernova (SN) core is the nucleon-nucleon bremsstrahlung. This process has been often modeled at the level of the vacuum one-pion exchange (OPE) approximation. Starting from this naive…
Due to their unique set of multimessenger signals, neutron star mergers have emerged as a novel environment for studies of new physics beyond the Standard Model (SM). As a case study, we consider the simplest extension of the SM scalar…
The coalescence of a neutron-star binary is likely to result in the formation of a neutron-star merger remnant for a large range of binary mass configurations. The massive merger remnant shows strong oscillations, which are excited by the…
Based on the formalism by Kaminker et al. (Astron. Astrophys. 343 (1999) 1009) we derive an analytic approximation for neutrino-pair bremsstrahlung emissivity due to scattering of electrons by atomic nuclei in the neutron star crust of any…
In order to extract maximal information from neutron-star merger signals, both gravitational and electromagnetic, we need to ensure that our theoretical models/numerical simulations faithfully represent the extreme physics involved. This…
Nuclear reactions occurring deep in the crust of a transiently accreting neutron star efficiently maintain the core at a temperature >5e7 K. When accretion halts, the envelope relaxes to a thermal equilibrium set by the flux from the hot…