The stochastic X-ray variability of the accreting millisecond pulsar MAXI J0911-655
- Creators
- Bult, Peter
Abstract
In this work, I report on the stochastic X-ray variability of the 340 Hz accreting millisecond pulsar MAXI J0911–655. Analyzing pointed observations of the XMM-Newton and NuSTAR observatories, I find that the source shows broad band-limited stochastic variability in the 0.01-10 Hz range with a total fractional variability of ~24% rms in the 0.4-3 keV energy band that increases to ~40% rms in the 3–10 keV band. Additionally, a pair of harmonically related quasi-periodic oscillations (QPOs) are discovered. The fundamental frequency of this harmonic pair is observed between frequencies of 62 and 146 mHz. Like the band-limited noise, the amplitudes of the QPOs show a steep increase as a function of energy; this suggests that they share a similar origin, likely the inner accretion flow. Based on their energy dependence and frequency relation with respect to the noise terms, the QPOs are identified as low-frequency oscillations and discussed in terms of the Lense–Thirring precession model.
Additional Information
© 2017 The American Astronomical Society. Received 2017 January 5; revised 2017 February 3; accepted 2017 February 8; published 2017 March 3. I would like to thank Marieke van Doesburgh for sharing some of the data behind Figure 4 and the referee for constructive feedback that helped improve the paper. This work was supported by an NPP fellowship at NASA Goddard Space Flight Center.Attached Files
Accepted Version - 1702.04182.pdf
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Additional details
- Eprint ID
- 74470
- Resolver ID
- CaltechAUTHORS:20170222-115108839
- Created
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2017-02-22Created from EPrint's datestamp field
- Updated
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2021-11-11Created from EPrint's last_modified field
- Caltech groups
- NuSTAR