Study of temporal and spectral characteristics of the X-ray emission from solar flares

TL;DR

This study analyzes the temporal and spectral properties of X-ray emissions from 60 solar flares, revealing energy-dependent behaviors and correlations with magnetic field complexity, using data from the SOXS instrument over 2003-2011.

Contribution

It provides a comprehensive analysis of X-ray flare characteristics across multiple energy bands and links these properties to magnetic field complexity and cooling mechanisms.

Findings

Moderate correlation between rise time and peak flux of the first flare peak.

Inverse relation between DEM peak delay and flare peak flux.

Energy-dependent temporal and intensity variations linked to magnetic field configuration.

Abstract

Temporal and spectral characteristics of X-ray emission from 60 flares of intensity $\ge$C class observed by Solar X-ray Spectrometer (SOXS) during 2003-2011 are presented. We analyse the X-ray emission observed in four and three energy bands by the Si and CZT detectors, respectively. The number of peaks in the intensity profile of the flares varies between 1 and 3. We find moderate correlation (R$\simeq$0.2) between the rise time and the peak flux of the first peak of the flare irrespective to energy band, which is indicative of its energy-independent nature. Moreover, magnetic field complexity of the flaring region is found to be anti-correlated (R=0.61) with the rise time of the flares while positively correlated (R=0.28) with the peak flux of the flare. The time delay between the peak of the X-ray emission in a given energy band and that in the 25-30 keV decreases with increasing energy suggesting conduction cooling to be dominant in the lower energies. Analysis of 340 spectra from 14 flares reveals that the peak of Differential Emission Measure (DEM) evolution delays by 60-360 s relative to that of the temperature, and this time delay is inversely proportional to the peak flux of the flare. We conclude that temporal and intensity characteristics of flares are energy dependent as well as magnetic field configuration of the active region.