Constraints on Neutron Star Crusts from Oscillations in Giant Flares
- Joint Institute for Nuclear Astrophysics, National Superconducting Cyclotron Laboratory and the Department of Physics and Astronomy, Michigan State University, East Lansing, Michigan (United States)
We show that the fundamental seismic shear mode, observed as a quasiperiodic oscillation in giant flares emitted by highly magnetized neutron stars, is particularly sensitive to the nuclear physics of the crust. The identification of an oscillation at {approx_equal}30 Hz as the fundamental crustal shear mode requires a nuclear symmetry energy that depends very weakly on density near saturation. If the nuclear symmetry energy varies more strongly with density, then lower frequency oscillations, previously identified as torsional Alfven modes of the fluid core, could instead be associated with the crust. If this is the case, then future observations of giant flares should detect oscillations at around 18 Hz. An accurate measurement of the neutron-skin thickness of lead will also constrain the frequencies predicted by the model.
- OSTI ID:
- 21370793
- Journal Information:
- Physical Review Letters, Vol. 103, Issue 18; Other Information: DOI: 10.1103/PhysRevLett.103.181101; (c) 2009 The American Physical Society; ISSN 0031-9007
- Country of Publication:
- United States
- Language:
- English
Similar Records
The Neutron Star Crust: Symmetry Energy and Shear Moduli
Nonuniform nuclear structures and QPOs in giant flares