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Full-Text Articles in Physical Sciences and Mathematics
Wide Binary Systems And The Nature Of High-Velocity White Dwarfs, Nicole M. Silvestri, Terry D. Oswalt, Suzanne L. Hawley
Wide Binary Systems And The Nature Of High-Velocity White Dwarfs, Nicole M. Silvestri, Terry D. Oswalt, Suzanne L. Hawley
Aerospace, Physics, and Space Science Faculty Publications
We present measured radial velocities and complete space motions for 116 white dwarf stars with M dwarf companions. Thirteen pairs have " halo-like " velocities. According to a recent study by Oppenheimer et al., all these high-velocity white dwarfs should be considered part of the dark matter heavy halo of the Galaxy, based on their kinematics. Based on the near-solar abundance levels of the M dwarf companions, we conclude that 12 of our 13 high-velocity white dwarfs are actually part of the high-velocity tail of the thick disk, rather than the dark matter halo of the Galaxy, in agreement with …
Asteroseismology Of Rxj 2117+3412, The Hottest Pulsating Pg 1159 Star, G Vauclair, Matt A. Wood
Asteroseismology Of Rxj 2117+3412, The Hottest Pulsating Pg 1159 Star, G Vauclair, Matt A. Wood
Aerospace, Physics, and Space Science Faculty Publications
The pulsating PG 1159 planetary nebula central star RXJ 2117+3412 has been observed over three successive seasons of a multisite photometric campaign. The asteroseismological analysis of the data, based on the 37 identified ℓ = 1 modes among the 48 independent pulsation frequencies detected in the power spectrum, leads to the derivation of the rotational splitting, the period spacing and the mode trapping cycle and amplitude, from which a number of fundamental parameters can be deduced. The average rotation period is 1.16 ± 0.05 days. The trend for the rotational splitting to decrease with increasing periods is incompatible with a …