The computer code WASEM is suitable when an original data map (e.g. imaging data, space-time diagram, dynamic spectrum) consists of a mixture of different structures that are observed at the same location or frequencies during the same time interval. In such a case, weaker but interesting physical phenomenon may coincide with a strong emission. Usually, this strong component is well detectable, while the weak one remains hidden. This type of situation is characteristic of complex (e.g. radio, (E)UV) spectra that are observed during e.g. solar flares, which can consist of different types of bursts, plasma jets, or MHD waves and oscillations. When we want to separate individual temporal or spatial components from one another, we can use WASEM to learn about the hidden structures, if they exist that is. The separated physical phenomena can be easily analysed with a more precise determination of their parameters. This method can also be used for instrumental interference filtering.
Left panels: Original radio dynamic spectrum (upper panel) and separated waves with pulses (bottom panel). Middle panels: Original radio dynamic spectrum (upper panel) and separated drifting bursts (bottom panel). Right panels: Original time-slice diagram for the SDO/AIA 131Å channel (upper panel) and separated EUV flows (jets).
Numerical simulation of an artificial space-time diagram demonstrates WASEM possibilities. For example, that also very weak physical phenomena located on a small area of the original map can be successully revealed among other significantly stronger phenomena localized over whole data map.
The code is written in IDL.
Program is available upon request.
Last update: 2.10.2022