Abstract Details
| Name: Amitesh Omar Affiliation: ARIES, Nainital Conference ID: ASI2019_359 Title : Observations of high redshift radio galaxies with 3.6-m Devasthal Optical Telescope Authors and Co-Authors : Amitesh Omar (on behalf of a larger collaboration) Abstract Type : Oral Abstract Category : Extragalactic Astronomy Abstract : We will present 3.6-m Devasthal optical telescope detections of a probable z~5 radio galaxy, previously detected in GMRT-TGSS images at 150 MHz. The flux density of the galaxy is estimated to be ~1 microJy in optical i-band. The galaxy is not detected in optical r-band within a depth of ~0.5 microJy, making it a highly probable r-drop out galaxy. The optical image appears slightly extended. The observed field seems to have some more faint objects which are detected in i-band but not in r-band in vicinity of the radio galaxy. It suggests presence of some clustering of sources likely in a distant cluster. The observations were made using the faint object spectrograph and camera, which is optimized for observations in the red bands (r,i, and z) with efficiency of 40-45% in r/i bands and ~20% in z-band. The camera is expected to have efficiency of ~4% even at 1 micron wavelength. High redshift radio galaxies identified by their steep spectral index are the prime targets for optical identification and subsequently follow-up spectroscopic observations to confirm redshift with large apertures optical telescopes. The 3.6-m aperture should be suitable for optical identification down to ~26 mag in r/i bands. We will also present our ongoing efforts to obtain deep images with the 3.6-m telescope. This work is being carried out in collaboration with Leiden extra-galactic astronomy group. |