view with $0.''25$ pixels scale. For the basic data reduction, we subtracted dark and sky background from each individual dithered image and then normalized it by a flat image. We finally combined the individual images to make a final image. The seeing was typically $0.''8$–$1''$ over the observations. We obtained the flux calibration of our narrow-band filter (i.e., and ) images using the H (for 164) and Ks (for 212) band magnitudes of $\ge 20$ nearby isolated, unsaturated 2MASS stars. For this, we first converted the 2MASS magnitudes to fluxes [@coh03], and then obtained the fluxes of the and emission after we deconvolved the responsivities of both WIRC (and ) and 2MASS ($H$ and $K_s$) filters. The overall uncertainty in the flux calibration is less than $10 \%$. We attribute the major source of uncertainty to the different band response of each filter as the uncertainty in photometry itself is typically a few percent. For the astrometric solutions of our images, we used all the cataloged 2MASS stars in the field, and found that they are consistent with that of 2MASS with rms uncertainty of $0.''15$.

After identifying several emission-line features in the aforementioned imaging observations, we have carried out 