Relationship of decametric-hectometric type II radio burst, coronal mass ejections and solar flare observed during 1997–2014

• The starting frequency of 85% DH type-II bursts lies in the range of 1–14 MHz.
• DH type II radio bursts (1–16 MHz) originate between 2.2–4.5 RS.
• 48% DH Type II associated CMEs are located between ± 40° of solar central disc.
• Mean linear/initial speed of DH Type II associated CMEs are 1157/ 1200 km/s.
• Most of type II bursts are associated with strong SXR (X, M) class of solar flares.

In the present study we have investigated 426 DH Type II radio burst and associated CMEs events observed during the time period of 1997–2014. The starting frequency of most of associated DH type-II bursts (85%) lies in the range of 1–14 MHz (364 out of 426) with mean value of starting frequency is ∼11 MHz. The study of starting frequency (1–16 MHz) of DH type II bursts and heliocentric distance in solar radii indicate that DH type II radio bursts originate from 2.2–4.5 (RS) heliocentric distance in solar radii. We also found that the ∼ 48% DH Type II radio bursts associated CMEs are located between ± 40° of solar central disc and we also found that duration of DH type II radio bursts located at solar disc center are more than the duration of DH type II radio bursts located at solar limb. It is found that mean value for linear and initial speed of DH Type II associated CMEs are 1157 km/s and 1200 km/s, respectively. The CMEs speed are not correlated with duration of DH Type II radio bursts indicate that the durations of DH Type II radio bursts does not depend on speed of CMEs. The study also show that 426 DH type II radio bursts associated CMEs/flares occurred when there is coronal holes(CH) in nearby area and the mean distance between DH type II burst associated CMEs/ flares and boundary of coronal hole (CH) is 26°. The study also shows that there is no relation between drift velocity of DH type II radio bursts and speed of CMEs. The study also indicate that about 45% flares those associated DH Type II radio bursts have duration about 60 minutes and long duration DH Type II radio bursts are associated with X-class flares. We have also discussed that the results obtained in the present investigation in view of latest heliophysics interpretations.