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arXiv · 1806.03650

A Refined Search for Pulsations in White Dwarf Companions to Millisecond Pulsars

Mukremin Kilic·J. J. Hermes·A. H. Corsico·Alekzander Kosakowski·Warren R. Brown·John Antoniadis·Leila M. Calcaferro·A. Gianninas·Leandro G. Althaus·M. J. Green
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Abstract

We present optical high-speed photometry of three millisecond pulsars with low-mass ($< 0.3 M_{\odot}$) white dwarf companions, bringing the total number of such systems with follow-up time-series photometry to five. We confirm the detection of pulsations in one system, the white dwarf companion to PSR J1738+0333, and show that the pulsation frequencies and amplitudes are variable over many months. A full asteroseismic analysis for this star is under-constrained, but the mode periods we observe are consistent with expectations for a $M_{\star} = 0.16 - 0.19 M_{\odot}$ white dwarf, as suggested from spectroscopy. We also present the empirical boundaries of the instability strip for low-mass white dwarfs based on the full sample of white dwarfs, and discuss the distinction between pulsating low-mass white dwarfs and subdwarf A/F stars.

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Mukremin Kilic, J. J. Hermes, A. H. Corsico, Alekzander Kosakowski, Warren R. Brown, John Antoniadis, Leila M. Calcaferro, A. Gianninas, Leandro G. Althaus, M. J. Green. 2018-06-10. A Refined Search for Pulsations in White Dwarf Companions to Millisecond Pulsars. https://doi.org/10.1093/mnras%2Fsty1546

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