Forward Modeling of Simulated Transverse Oscillations in Coronal Loops and the Influence of Background Emission
arXiv:2109.02338 · doi:10.3847/1538-4357/ac2497
Abstract
We simulate transverse oscillations in radiatively cooling coronal loops and forward-model their spectroscopic and imaging signatures, paying attention to the influence of background emission. The transverse oscillations are driven at one footpoint by a periodic velocity driver. A standing kink wave is subsequently formed and the loop cross-section is deformed due to the Kelvin-Helmholtz instability, resulting in energy dissipation and heating at small scales. Besides the transverse motions, a long-period longitudinal flow is also generated due to the ponderomotive force induced slow wave. We then transform the simulated straight loop to a semi-torus loop and forward-model their spectrometer and imaging emissions, mimicking observations of Hinode/EIS and SDO/AIA. We find that the oscillation amplitudes of the intensity are different at different slit positions, but are roughly the same in different spectral lines or channels. X-t diagrams of both the Doppler velocity and the Doppler width show periodic signals. We also find that the background emission dramatically decreases the Doppler velocity, making the estimated kinetic energy two orders of magnitude smaller than the real value. Our results show that background subtraction can help recover the real oscillation velocity. These results are helpful for further understanding transverse oscillations in coronal loops and their observational signatures. However, they cast doubt on the spectroscopically estimated energy content of transverse waves using the Doppler velocity.
arXiv commentAccepted for publication in ApJ
References in corpus (36)
- PLUTO: a Numerical Code for Computational Astrophysics
- CHIANTI - an atomic database for emission lines - Paper XV: Version 9, improvements for the X-ray satellite lines
- EUV emission lines and diagnostics observed with Hinode/EIS
- Persistent Doppler shift oscillations observed with HINODE/EIS in the solar corona: spectroscopic signatures of Alfvenic waves and recurring upflows
- Nonlinear Instability of kink oscillations due to shear motions
- Decayless low-amplitude kink oscillations: a common phenomenon in the solar corona?
- Growing transverse oscillations of a multistranded loop observed by SDO/AIA
- Fine strand-like structure in the solar corona from MHD transverse oscillations
- Resonant Absorption of Transverse Oscillations and Associated Heating in a Solar Prominence. II- Numerical aspects
- A statistical study of decaying kink oscillations detected using SDO/AIA
- The Multi-slit Approach to Coronal Spectroscopy with the Multi-slit Solar Explorer (MUSE)
- Estimating the "Dark" Energy Content of the Solar Corona
- Heating by transverse waves in simulated coronal loops
- Line-of-sight Effects on Observability of Kink and Sausage Modes in Coronal Structures with Imaging Telescopes
- Damping of nonlinear standing kink oscillations: a numerical study
- Heating effects from driven transverse and Alfvén waves in coronal loops
- Modelling observed decay-less oscillations as resonantly enhanced Kelvin-Helmholtz vortices from transverse MHD waves and their seismological application
- Line-of-sight geometrical and instrumental resolution effects on intensity perturbations by sausage modes
- Excitation of decay-less transverse oscillations of coronal loops by random motions
- Contribution of mode coupling and phase-mixing of Alfvén waves to coronal heating
- Forward Modelling of Standing Slow Modes in Flaring Coronal Loops
- Amplitudes and energy fluxes of simulated decayless kink oscillations
- Numerical simulations of transverse oscillations in radiatively cooling coronal loops
- The First 3D Coronal Loop Model Heated by MHD Waves against Radiative Losses
- Forward Modelling of Standing Kink Modes in Coronal Loops I. Synthetic Views
- Wave heating in gravitationally stratified coronal loops in the presence of resistivity and viscosity
- Cool transition region loops observed by the Interface Region Imaging Spectrograph
- Plasma parameters and geometry of cool and warm active region loops
- Generating transverse loop oscillations through a steady-flow driver
- Forward Modelling of Propagating Slow Waves in Coronal Loops and Their Frequency-Dependent Damping
- Transverse loop oscillations via vortex shedding: a self oscillating process
- Coronal loop transverse oscillations excited by different driver frequencies
- Wave heating in simulated multi-stranded coronal loops
- Revisiting the relation between nonthermal line widths and transverse MHD wave amplitudes
- On the spectroscopic detection of periodic plasma flows in loops undergoing thermal non-equilibrium
- Synthetic Extreme-ultraviolet Emissions Modulated by Leaky Fast Sausage Modes in Solar Active Region Loops