Skip to main content

On the spin-down of intermittent pulsars

Author(s): Li, J; Spitkovsky, Anatoly; Tchekhovskoy, A

To refer to this page use:
Abstract: Magnetospheres of pulsars are thought to be filled with plasma, and variations in plasma supply can affect both pulsar emission properties and spin-down rates. A number of recently discovered "intermittent" pulsars switch between two distinct states: an "on," radio-loud state, and an "off," radio-quiet state. Spin-down rates in the two states differ by a large factor, ∼1.5-2.5, which is not easily understood in the context of current models. In this Letter, we present self-consistent numerical solutions of "on" and "off" states of intermittent pulsar magnetospheres. We model the "on" state as a nearly ideal force-free magnetosphere with abundant magnetospheric plasma supply. The lack of radio emission in the "off" state is associated with plasma supply disruption that results in lower plasma density on the open field lines. We model the "off" state using nearly vacuum conditions on the open field lines and nearly ideal force-free conditions on the closed field lines, where plasma can remain trapped even in the absence of pair production. The toroidal advection of plasma in the closed zone in the "off" state causes spin-downs that are a factor of ∼2higher than vacuum values, and we naturally obtain a range of spin-down ratios between the "on" and "off" states, ∼1.2-2.9, which corresponds to a likely range of pulsar inclination angles of 30°-90°. We consider the implications of our model to a number of poorly understood but possibly related pulsar phenomena, including nulling, timing noise, and rotating radio transients.
Publication Date: 2-Feb-2012
Electronic Publication Date: 20-Feb-2012
Citation: Li, J, Spitkovsky, A, Tchekhovskoy, A. (2012). On the spin-down of intermittent pulsars. Astrophysical Journal Letters, 746 (2), 10.1088/2041-8205/746/2/L24
DOI: doi:10.1088/2041-8205/746/2/L24
ISSN: 2041-8205
EISSN: 2041-8213
Related Item:
Type of Material: Journal Article
Journal/Proceeding Title: Astrophysical Journal Letters
Version: Final published version. Article is made available in OAR by the publisher's permission or policy.

Items in OAR@Princeton are protected by copyright, with all rights reserved, unless otherwise indicated.