165 citations · 485 across the 16 of their papers we have counts for
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Dynamo Simulations Confirm Predominantly Toroidal Fields in Near-Core Region of an Intermediate-Mass Star
R. P. Ratnasingam, T. M. Rogers
Recent asteroseismic analysis of the main-sequence F star KIC 9244992 has revealed evidence for a strong, predominantly toroidal magnetic field in its deep radiative interior. Moti…
Numerical Simulations Confirm Wave-Induced Shear Mixing in Stellar Interiors
A. Varghese, R. P. Ratnasingam, L. Ramírez-Galeano +2
Internal Gravity Waves (IGWs) are thought to cause mixing in stellar interiors, a process that has been widely studied both theoretically and numerically. Our aim is to determine t…
Angular Momentum Transport by Internal Gravity Waves Across Age
Tamara Marie Rogers, Rathish Previn Ratnasingam
We present two-dimensional numerical simulations of convection and waves in a 7 solar mass star across stellar ages ranging from zero age to terminal-age-main-sequence. We show tha…
Calibrating chemical mixing induced by internal gravity waves based on hydrodynamical simulations; The chemical evolution of OB-type stars
J. S. G. Mombarg, A. Varghese, R. P. Ratnasingam
Internal gravity waves (IGWs) have been shown to contribute to the transport of chemical elements in stars with a convective core and radiative envelope. Recent 2D hydrodynamical s…
On the Geometry of the Near-Core Magnetic Field in Massive Stars
Rathish P. Ratnasingam, Philipp V. F. Edelmann, Dominic M. Bowman +1
It is well-known that the cores of massive stars sustain a stellar dynamo with a complex magnetic field configuration. However, the same cannot be said for the field's strength and…
Effect of Rotation on Wave Mixing in Intermediate Mass Stars
A. Varghese, R. P. Ratnasingam, R. Vanon +3
Internal gravity waves (IGWs) are likely to cause mixing in stellar interiors. Studies show that the mixing by these waves changes drastically across age and mass (Varghese et al.…
Three-Dimensional Simulations of Massive Stars: II. Age Dependence
R. Vanon, P. V. F. Edelmann, R. P. Ratnasingam +2
We present 3D full star simulations, reaching up to 90% of the total stellar radius, for three stars of different ages (ZAMS, midMS and TAMS). A comparison with several…
Internal Gravity Waves in Massive Stars II: Frequency Analysis Across Stellar Mass
R. P. Ratnasingam, T. M. Rogers, S. Chowdhury +4
Stars with masses above 1.6 solar masses generally possess convective cores and radiative envelopes, which allows the propagation of outward-travelling internal gravity waves. We h…
Chemical Mixing Induced by Internal Gravity Waves in Intermediate Mass Stars
A. Varghese, R. P. Ratnasingam, R. Vanon +2
Internal gravity waves (IGWs) can cause mixing in the radiative interiors of stars. We study this mixing by introducing tracer particles into two - dimensional (2D) hydrodynamic si…
Two-Dimensional Simulations of Internal Gravity Waves in The Radiation Zones of Intermediate-Mass Stars
R. P. Ratnasingam, P. V. F. Edelmann, T. M. Rogers
Intermediate-mass main sequence stars have large radiative envelopes overlying convective cores. This configuration allows internal gravity waves (IGWs) generated at the convective…
Fully compressible simulations of waves and core convection in main-sequence stars
L. Horst, P. V. F. Edelmann, R. Andrassy +4
Context. Recent, nonlinear simulations of wave generation and propagation in full-star models have been carried out in the anelastic approximation using spectral methods. Although…
Low-frequency gravity waves in blue supergiants revealed by high-precision space photometry
Dominic M. Bowman, Siemen Burssens, May G. Pedersen +14
Almost all massive stars explode as supernovae and form a black hole or neutron star. The remnant mass and the impact of the chemical yield on subsequent star formation and galacti…
Three-Dimensional Simulations of Massive Stars: I. Wave Generation and Propagation
P. V. F. Edelmann, R. P. Ratnasingam, M. G. Pedersen +3
We present the first three-dimensional (3D), hydrodynamic simulations of the core convection zone (CZ) and extended radiative zone spanning from 1% to 90% of the stellar radius of…
Astro2020 Science White Paper: gravity-wave asteroseismology of intermediate- and high-mass stars
Andrew Tkachenko, Conny Aerts, Dominic M. Bowman +17
The evolution of a star is driven by the physical processes in its interior making the theory of stellar structure and evolution the most crucial ingredient for not only stellar ev…
Onset of Nonlinear Internal Gravity Waves in Intermediate-Mass Stars
R. P. Ratnasingam, P. V. F. Edelmann, T. M. Rogers
Internal gravity waves (IGW) propagate in the radiation zones of all stars. During propagation, their amplitudes are affected by two main features: radiative diffusion and density…
A BRITE view on the massive O-type supergiant V973 Scorpii: Hints towards internal gravity waves or subsurface convection zones
Tahina Ramiaramanantsoa, Rathish Ratnasingam, Tomer Shenar +9
Stochastically-triggered photospheric light variations reaching mmag peak-to-valley amplitudes have been detected in the O8Iaf supergiant V973 Scorpii as the outcome of…