Relationship of great soft X-ray flares with other solar activity phenomena

Abstract

We present study of relationship of GSXR flares with Hα flares, hard X-ray (HXR) bursts, microwave (MW) bursts at 15.4 GHz, type II/IV radio bursts, coronal mass ejections (CMEs), protons flares (>10 MeV) and ground level enhancement (GLE) events we find that about 85.7%, 93%, 97%, 69%, 60%, 11.1%, 79%, 46%, and 23%% GSXR flares are related/associated with observed Hα flares, HXR bursts, MW bursts at 15.4 GHz, type II radio bursts, type IV radio bursts, GLE events, CMEs, halo CMEs, and proton flares (>10 MeV), respectively. In the paper we have studied the onset time delay of GSXR flares with Hα flares, HXR, and MW bursts which shows the during majority GSXR flares SXR emissions start before the Hα, HXR and MW emissions, respectively while during 15–20% of GSXR flares the SXR emissions start after the onset of Hα, HXT and MW emissions, respectively indicating two types of solar flares. The, onset time interval between SXR emissions and type II radio bursts, type IV radio bursts, GLE events CMEs, halo CMEs, and protons flares are 1–15 min, 1–20 min, 21–30 min, 21–40 min, 21–40 min, and 1–4 hrs, respectively. Following the majority results we are of the view that the present investigations support solar flares models which suggest flare triggering first in the corona and then move to chromospheres/ photosphere to starts emissions in other wavelengths. The result of the present work is largely consistent with “big flare syndrome” proposed by Kahler (1982).