GRAVITATIONAL-WAVE SPIN-DOWN AND STALLING LOWER LIMITS ON THE ELECTRICAL RESISTIVITY OF THE ACCRETED MOUNTAIN IN A MILLISECOND PULSAR

作者：Vigelius M^*; Melatos A

来源：Astrophysical Journal, 2010, 717(1): 404-410.

DOI：10.1088/0004-637X/717/1/404

• accretion, accretion disks
• pulsars: general
• stars: magnetic field
• stars: neutron

The electrical resistivity of the accreted mountain in a millisecond pulsar is limited by the observed spin-down rate of binary radio millisecond pulsars (BRMSPs) and the spins and X-ray fluxes of accreting millisecond pulsars (AMSPs). We find eta >= 10(-28) s (tau(SD)/1Gyr)(-0.8) (where tau(SD) is the spin-down age) for BRMSPs and eta >= 10(-25) s ((M) over dot(a)/(M) over dot(E))(0.6) (where (M) over dot(a) and (M) over dot(E) are the actual and Eddington accretion rates) for AMSPs. These limits are inferred assuming that the mountain attains a steady state, where matter diffuses resistively across magnetic flux surfaces but is replenished at an equal rate by infalling material. The mountain then relaxes further resistively after accretion ceases. The BRMSP spin-down limit approaches the theoretical electron-impurity resistivity at temperatures greater than or similar to 10(5) K for an impurity concentration of similar to 0.1, while the AMSP stalling limit falls 2 orders of magnitude below the theoretical electron-phonon resistivity for temperatures above 10(8) K. Hence, BRMSP observations are already challenging theoretical resistivity calculations in a useful way. Next-generation gravitational-wave interferometers will constrain eta at a level that will be competitive with electromagnetic observations.

• 出版日期2010-7-1