Optical detection of a GMRT-detected candidate high-redshift radio galaxy with 3.6-m Devasthal optical telescope

We report optical observations of TGSS J1054+5832, a candidate high-redshift ( z=4.8± 2 ) steep-spectrum radio galaxy, in r and i bands, using the faint object spectrograph and camera mounted on 3.6-m Devasthal Optical Telescope (DOT). The source previously detected at 150 MHz from Giant Meterwave Radio Telescope (GMRT) and at 1420 MHz from Very Large Array has a known counterpart in near-infrared bands with K -band magnitude of AB 22. The source is detected in i -band with AB 24.3± 0.2 magnitude in the DOT images presented here. The source remains undetected in the r -band image at a 2.5 σ depth of AB 24.4 mag over an 1.2”× 1.2” aperture. An upper limit to i-K color is estimated to be ∼ 2.3, suggesting youthfulness of the galaxy with active star formation. These observations highlight the importance and potential of the 3.6-m DOT for detections of faint galaxies.