Articulo
A refined search for pulsations in white dwarf companions to millisecond pulsars
Autor
Kilic, Mukremin
Hermes, J. J.
Córsico, Alejandro Hugo
Kosakowski, Alekzander
Brown, Warren R.
Antoniadis, John
Calcaferro, Leila Magdalena
Gianninas, A.
Althaus, Leandro Gabriel
Green, M. J.
Institución
Resumen
We present optical high-speed photometry of three millisecond pulsars with low-mass (< 0.3M⊙) white dwarf companions, bringing the total number of such systemswith 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 underconstrained, but the mode periods we observe are consistent with expectations for an M⁎ = 0.16-0.19 M⊙ 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. Instituto de Astrofísica de La Plata Facultad de Ciencias Astronómicas y Geofísicas