that our measured continuum level is consistent (or in agreement) with the photometry.

We use two approaches to calculate the [H$\alpha$]{} line flux: 1) direct flux measurement and 2) Gaussian fit to sky-line blended and kinematically unresolved emission lines. Our two methods provide consistent results for emission-lines that are not blended with sky lines (see Appendix \[sec:cont\_Halpha\_test\]). By visual inspection, we selected kinematically resolved (due to galaxy rotation etc.) [H$\alpha$]{} emission lines that were not blended with sky-lines and computed the EW by integrating the line flux. Within the defined emission line region, we calculated the [H$\alpha$]{} flux by subtracting the flux at each pixel ($F_i$) by the corresponding continuum level of the pixel ($F_{cont_i}$). For the remaining sample, which comprises of galaxies with no strong velocity structure and galaxies with [H$\alpha$]{} emission with little velocity structure and/or [H$\alpha$]{} contaminated by sky lines, we perform Gaussian fits to the emission lines, to calculate the [H$\alpha$]{} flux values. We then subtract the continuum level from the computed [H$\alpha$]{} line flux.

Next, we use the calculated [H$\alpha$]{} flux along with the fitted continuum level to calculate the observed [H$\alpha$]{} EW ($H\alpha_{EW_{obs}}$) as follows:

$$\label{eq:Ha_EW_obs}
H\alpha\ EW_{obs} =  \sum_{i} (1-\frac{F_i - F_{cont_i}}{F_{cont_i}}) \times 