How to drive roAp stars

Abstract

Rapidly oscillating Ap stars consitute a unique class of pulsators to study nonradial oscillations under some - even for stars - unusual physical conditions. These stars are chemically peculiar, they have strong magnetic fields, and they often pulsate in several high-order acoustic modes simultaneously. We discuss here an excitation mechanism for short-period oscillation modes based on the classical kappa mechanism. We particularly stress the conditions that must be fulfilled for successful driving. Specifically, we discuss the roles of chemical peculiarity and strong magnetic field on the oscillation modes and what separates these pulsators from delta Scuti and Am-type stars.

11 pages, 15 figures, to be published in MNRAS

Cited by in corpus (16)

• Radial Velocity Variations in Pulsating Ap Stars. II. 33 Librae
• Testing excitation models of rapidly oscillating Ap stars with interferometry
• On the first $\delta$ Sct--roAp hybrid pulsator and the stability of p and g modes in chemically peculiar A/F stars
• Time-series spectroscopy of the rapidly oscillating Ap star HR 3831
• The Nainital-Cape Survey-III : A Search for Pulsational Variability in Chemically Peculiar Stars
• Discovery of the longest-period rapidly oscillating Ap star HD177765
• On mode conversion and wave reflection in magnetic Ap stars
• Pulsations in the atmosphere of the roAp star HD 24712 II. Theoretical models
• Asteroseismic g-mode period spacings in strongly magnetic rotating stars
• On the understanding of pulsations in the atmosphere of roAp stars: phase diversity and false nodes
• The roAp stars observed by the Kepler Space Telescope
• New light on the driving mechanism in roAp stars. Part I. Effects of metallicity
• Simulations of magneto-acoustic pulsations in atmospheres of rapidly oscillating Ap stars
• LCO observations of a super-critical distorted pulsation in the roAp star J0855 (TYC 2488-1241-1)
• Asteroseismic Theory of Rapidly Oscillating Ap Stars
• Pulsation models for the roAp star HD 134214