Introducing CAFein, a New Computational Tool for Stellar Pulsations and Dynamic Tides

Abstract

Here we present CAFein, a new computational tool for investigating radiative dissipation of dynamic tides in close binaries and of non-adiabatic, non-radial stellar oscillations in isolated stars in the linear regime. For the latter, CAFein computes the non-adiabatic eigenfrequencies and eigenfunctions of detailed stellar models. The code is based on the so-called Riccati method, a numerical algorithm that has been successfully applied to a variety of stellar pulsators, and which doesn't suffer of the major drawbacks of commonly used shooting and relaxation schemes. Here we present an extension of the Riccati method to investigate dynamic tides in close binaries. We demonstrate CAFein's capabilities as a stellar pulsation code both in the adiabatic and non-adiabatic regime, by reproducing previously published eigenfrequencies of a polytrope, and by successfully identifying the unstable modes of a stellar model in the $\beta$ Cephei/SPB region of the Hertzsprung-Russell diagram. Finally, we verify CAFein's behavior in the dynamic tides regime by investigating the effects of dynamic tides on the eigenfunctions and orbital and spin evolution of massive Main Sequence stars in eccentric binaries, and of hot Jupiter host stars. The plethora of asteroseismic data provided by the NASA's Kepler satellite, some of which include the direct detection of tidally excited stellar oscillations, make CAFein quite timely. Furthermore, the increasing number of observed short-period detached double white dwarfs (WD) and the observed orbital decay in the tightest of such binaries open up a new possibility of investigating WD interiors through the effects of tides on their orbital evolution

17 pages, 9 figures, 6 tables. Accepted for publication in ApJ. Revised to match the accepted version. A new section on dynamic tides in a binary hosting a hot Jupiter has been added

References in corpus (5)

• Modules for Experiments in Stellar Astrophysics (MESA)
• The ELM Survey. I. A Complete Sample of Extremely Low Mass White Dwarfs
• Tidal dissipation in binary systems
• Rapid Orbital Decay in the 12.75-minute WD+WD Binary J0651+2844
• Dynamical Tides in Compact White Dwarf Binaries: Helium Core White Dwarfs, Tidal Heating, and Observational Signatures

Cited by in corpus (7)

• GYRE: An open-source stellar oscillation code based on a new Magnus Multiple Shooting Scheme
• Tidal Dissipation and Obliquity Evolution in Hot Jupiter Systems
• gyre_tides: Modeling binary tides within the gyre stellar oscillation code
• Tidally Excited Oscillations in Heartbeat Binary Stars: Pulsation Phases and Mode Identification
• Long-term evolution of double white dwarf binaries accreting through direct impact
• Visibility of unstable oscillation modes in a rapidly rotating B star
• Resonance locking and tidal evolution in rotating γ-Doradus binaries