Thermodynamic Spectrum of Solar Flares Based on SDO/EVE Observations: Techniques and Statistical Results

摘要: SDO/EVE provides rich information of the thermodynamic processes solar activities, particularly flares. Here, we develop a method to construct spectrum (TDS) charts based on EVE spectral lines. This tool could be potentially useful EUV astronomy learn eruptive activities distant astronomical objects. Through several cases, illustrate what can from TDS charts. Furthermore, apply 74 flares equal or greater than M5.0-class, and reach following statistical results. First, peaks are always behind soft X-ray (SXR) stronger tend have faster cooling rate. There is power law correlation between peak delay times rates, suggesting coherent process SXR emissions. Second, there two distinct temperature drift patterns, called Type I II. For flares, enhanced emission drifts high low like quadrilateral, whereas for II pattern looks triangle. Statistical analysis suggests that more impulsive Third, late-phase intensity ratio late phase main roughly correlated with flare class, strong all confined. We believe re-deposition energy carried by flux rope, unsuccessfully erupts out, into thermal emissions responsible found in confined flare. Besides, some cases signatures chromosphere transition region These results provide new clues advance our understanding associated eruptions, e.g., coronal mass ejections.