Description
I present and discuss the steps taken to detect the signature of high redshift (z ~4) Lyman Break Galaxies (LBGs) within low signal-to-noise ratio (S/N) spectra. A new ranking procedure is described for the purpose of aiding in the certification of these low S/N ratio LBG detections. Lastly, new target selection methodologies are offered with the hope of improving future z ~4 LBG detection efficiencies. Target objects were selected from images taken with the Suprime-Cam imager mounted on the NAOJ Subaru telescope. Spectroscopic follow-up observations were conducted at the W. M. Keck Observatory utilizing the DEIMOS multi-slit spectrograph. Spectroscopic reductions were performed to identify potential LBGs, determine their redshifts, and assess the degree of assurance that the signals detected were actual signatures of LBGs using the newly developed ranking procedure. Twenty one LBGs of high confidence were found during this research including 10 at the desired z ~4 redshift. Numerous objects approximated the spectral energy distribution of LBGs and were found to be nearby M or K-type galactic stars, intermediate redshift early or late-type galaxies, high redshift active galactic nuclei, or quasi-stellar objects. Discrimination between the desired LBGs from these undesired "Fakers" assisted in the development of an improved LBG selection criteria and selection techniques. Standardizing the certification process of low S/N LBGs with a semi-analytic evaluation will benefit future studies of high redshift LBGs. Higher selection efficiencies for z ~4 LBG detections, with the newly developed "limit" and "goodness" target selection methodologies, will also bring rewards. Further evaluation will be conducted to explore the potential of applying these ranking and selection methodologies at other redshifts.
