Predicting the time variation of radio emission from MHD simulations of a flaring T-Tauri star

Charlotte Waterfall, Philippa Browning, Gary Fuller, Mykola Gordovskyy, S. Orlando, F. Reale

Research output: Contribution to journalArticlepeer-review


We model the time dependent radio emission from a disk accretion event in a
T-Tauri star using 3D, ideal magnetohydrodynamic simulations combined with a
gyrosynchrotron emission and radiative transfer model. We predict for the first time,
the multi-frequency (1-1000 GHz) intensity and circular polarisation from a flaring
T-Tauri star. A flux tube, connecting the star with its circumstellar disk, is populated
with a distribution of non-thermal electrons which is allowed to decay exponentially
after a heating event in the disk and the system is allowed to evolve. The energy
distribution of the electrons, as well as the non-thermal power law index and loss
rate, are varied to see their effect on the overall flux. Spectra are generated from
different lines of sight, giving different views of the flux tube and disk. The peak flux
typically occurs around 20−30 GHz and the radio luminosity is consistent with that
observed from T-Tauri stars. For all simulations, the peak flux is found to decrease
and move to lower frequencies with elapsing time. The frequency-dependent circular
polarisation can reach 10−30% but has a complex structure which evolves as the flare
evolves. Our models show that observations of the evolution of the spectrum and its
polarisation can provide important constraints on physical properties of the flaring
environment and associated accretion event.
Original languageEnglish
JournalRoyal Astronomical Society. Monthly Notices
Publication statusAccepted/In press - 5 Jun 2020


Dive into the research topics of 'Predicting the time variation of radio emission from MHD simulations of a flaring T-Tauri star'. Together they form a unique fingerprint.

Cite this