相关论文: Unstable Nonradial Oscillations on Helium Burning …
Thermonuclear burning on the surface of accreting neutron stars is observed to stabilize at accretion rates almost an order of magnitude lower than theoretical models predict. One way to resolve this discrepancy is by including a base…
Neutron stars, with their strong surface gravity, have interestingly short timescales for the sedimentation of heavy elements. Recent observations of unstable thermonuclear burning (observed as X-ray bursts) on the surfaces of slowly…
The Rossi X-ray Timing Explorer has detected nearly coherent oscillations in the tails of type I X-ray bursts from 17 low-mass X-ray binaries. The oscillations are thought to be generated by brightness fluctuations associated with a surface…
We consider the stability properties of the ocean of accreting magnetic neutron stars. It turns out that the ocean is always unstable due to the combined influence of the temperature and chemical composition gradients along the surface and…
The rotation rates of six weakly-magnetic neutron stars accreting in low-mass X-ray binaries have most likely been measured by Type I X-ray burst observations with RXTE. The nearly coherent oscillations detected during the few seconds of…
We investigate hydrogen electron capture in the oceans of neutron stars accreting at rates appropriate for most Low-Mass X-Ray Binaries. These stars burn the accreted hydrogen and helium unstably in the upper atmosphere and accumulate…
Hydrogen and/or helium accreted by a neutron star from a binary companion may undergo thermonuclear fusion. At different mass accretion rates different burning regimes are discerned. Theoretical models predict helium fusion to proceed as a…
Accreting neutron stars (NSs) often show coherent modulations during type I X-ray bursts, called burst oscillations. We consider whether a nonradial mode can serve as an explanation for burst oscillations from those NSs which are not…
The stability of thermonuclear burning of hydrogen and helium accreted onto neutron stars is strongly dependent on the mass accretion rate. The burning behavior is observed to change from Type I X-ray bursts to stable burning, with…
Accreting neutron stars exhibit Type I X-ray bursts from both frequent hydrogen/helium flashes as well as rare carbon flashes. The latter (superbursts) ignite in the ashes of the former. Hydrogen/helium bursts, however, are thought to…
During accretion, a neutron star (NS) is spun up as angular momentum is transported through its liquid surface layers. We study the resulting differentially rotating profile, focusing on the impact this has for type I X-ray bursts. The…
We investigate the atmosphere, ocean, and crust of neutron stars accreting at rates sufficiently high (typically in excess of the local Eddington limit) to stabilize the burning of accreted hydrogen and helium. For hydrogen-rich accretion…
During accretion a neutron star (NS) is spun up as angular momentum is transported through its surface layers. We study the resulting differentially rotating profile, focusing on the impact this has for type I X-ray bursts. The predominant…
Non-radial oscillation modes of a neutron star possess valuable information about its internal structure and nuclear physics. Starting from the quadrupolar order, such modes under general relativity are known as quasi-normal modes since…
Superbursts from accreting neutron stars probe nuclear reactions at extreme densities ($\rho \approx 10^{9}~g\,cm^{-3}$) and temperatures ($T>10^9~K$). These bursts ($\sim$1000 times more energetic than type I X-ray bursts) are most likely…
We look at the spreading of localized temperature perturbations in the accreted fuel layer of a non-rotating neutron star. The pressure at the base of the accreted fuel layer is large and the material is only partially degenerate. Any…
We have investigated an influence of the r-mode instability on hypercritically accreting ($\dot{M}\sim 1M_\odot {y}^{-1}$) neutron stars in close binary systems during their common envelope phases based on the scenario proposed by Bethe et…
Neutron stars, with their strong surface gravity, have interestingly short timescales for the sedimentation of heavy elements. Motivated by observations of Type I X-ray bursts from sources with extremely low persistent accretion…
Gravitational radiation tends to drive gravity modes in rotating neutron stars unstable. For an inviscid star, the instability sets in when the rotation frequency is about 0.7 times the corresponding mode frequency of the nonrotating star.…
We investigate marginally stable nuclear burning on the surface of accreting neutron stars as an explanation for the mHz quasi-periodic oscillations (QPOs) observed from three low mass X-ray binaries. At the boundary between unstable and…