Strong Emission-Line Galaxies at Low Redshifts in the Field around the Quasar SDSSp J104433.04−012502.2

We discuss the observational properties of strong emission-line galaxies at low redshifts found by our deep imaging survey for high-redshift Ly$$\alpha$$ emitters. In our survey, we used a narrow-band filter, NB816 ($$\lambda_{\mathrm{center}} = 8150 \,{Å}$$ with $$\mbox{FWHM} = 120 \,\mbox{Å}$$ FWHM$$= 120 \,{Å}$$), and an intermediate-band filter, IA827 ($$\lambda_{\mathrm{center}} = 8270 \,{Å}$$ with $$\mbox{FWHM} = 340 \,\mbox{Å}$$ FWHM$$= 340 \,{Å}$$). In this survey, 62 NB816-excess ($$\gt 0.9 \,\mathrm{mag} \gt 0.9 \,\mathrm{mag}$$) and 21 IA827-excess ($$\gt 0.8 \,\mathrm{mag} \gt 0.8 \,\mathrm{mag}$$) objects were found. Among them, we found 20 NB816-excess and 4 IA827-excess Ly$$\alpha$$ emitter candidates. Therefore, it turns out that 42 NB816-excess and 17 IA827-excess objects are strong emission-line objects at lower redshifts. Since 4 objects in the two low-$$z$$ samples are common, the total number of strong low-$$z$$ emitters is 55. Applying our photometric redshift technique, we identified 7 $$\mathrm{H}\alpha$$ emitters at $$z \approx 0.24$$, 20 $$\mathrm{H}\beta$$–[O III] ones at $$z \approx 0.65$$, and 11 [O II] ones at $$z \approx 1.19$$. However, we could not determine reliable photometric redshifts of the remaining 17 emitters. The distributions of their rest frame equivalent widths are consistently understood based on recent studies of galaxy evolution from $$z \sim 1$$ to $$z \sim 0$$.