On the Sensitivity of Black Widow Pulsars to the Stochastic Gravitational Wave Background
Abstract
In the past five years, one third of the 65 pulsars discovered by observing Fermi unassociated sources are black widow pulsars. Black widow pulsars are eclipsing binary millisecond pulsars with masses ranging from 0.01-0.1 solar masses. The companions in black widow systems exert small torques on the system causing the orbit to change on small but measurable time scales. Because adding parameters to a timing model reduces sensitivity to a gravitational wave signal, the need to fit many orbital frequency derivatives to the timing data is potentially problematic for using black widow pulsars to detect gravitational waves with pulsar timing arrays. Using simulated data with up to four binary frequency derivatives, we show that fitting for orbital period derivatives absorbs less than 5% of the low frequency spectrum expected from a stochastic gravitational wave background signal. Furthermore, this result does not change with orbital frequency. Therefore, we suggest that if timing noise can be accounted for by modeling orbital frequency derivatives and is not caused by spin frequency noise, pulsar timing array collaborations should include black widow pulsars in their array.
- Publication:
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American Astronomical Society Meeting Abstracts #225
- Pub Date:
- January 2015
- Bibcode:
- 2015AAS...22534612B