Can magnetic fields be detected during the inspiral of binary neutron stars?
Abstract
Using accurate and fully general-relativistic simulations we assess the effect that magnetic fields have on the gravitational-wave emission produced during the inspiral and merger of magnetized neutron stars. In particular, we show that magnetic fields have an impact after the merger, because they are amplified by a Kelvin-Helmholtz instability, but also during the inspiral, most likely because the magnetic tension reduces the stellar tidal deformation for extremely large initial magnetic fields, B0 >~ 1017G. We quantify the influence of magnetic fields by computing the overlap, , between the waveforms produced during the inspiral by magnetized and unmagnetized binaries. We find that for any realistic magnetic field strength B0 <~ 1014G the overlap during the inspiral is and is quite insensitive to the mass of the neutron stars. Only for unrealistically large magnetic fields like B0 ~= 1017G the overlap does decrease noticeably, becoming at our resolutions for stars with baryon masses Mb ~= 1.4/1.6Msolar, respectively. Because neutron stars are expected to merge with magnetic fields ~108-1010G and because present detectors are sensitive to , we conclude that it is very unlikely that the present detectors will be able to discern the presence of magnetic fields during the inspiral of neutron stars.
- Publication:
-
Monthly Notices of the Royal Astronomical Society
- Pub Date:
- October 2009
- DOI:
- 10.1111/j.1745-3933.2009.00745.x
- arXiv:
- arXiv:0901.2722
- Bibcode:
- 2009MNRAS.399L.164G
- Keywords:
-
- gravitational waves;
- magnetic fields;
- MHD;
- relativity;
- binaries: general;
- stars: neutron;
- General Relativity and Quantum Cosmology;
- Astrophysics - High Energy Astrophysical Phenomena
- E-Print:
- 5 pages, 4 figures. Small changes to text and figures. Matches version to appear on MNRAS Letters