Program: GN-2007B-Q-35

We request near-IR spectroscopy with GNIRS to investigate the rest-frame UV spectra of two recently discovered z>6 quasars. We will measure the location of the MgII emission lines to determine the systemic redshifts of the quasars. This is important for determining the size of the highly-ionized near-zones surrounding quasars which can be used to infer the neutral fraction of hydrogen before the quasar switched on. Accurate redshifts are also essential for searches for molecular and atomic millimetre lines to probe the evolutionary state of the host galaxy. The widths of the MgII lines will be used to estimate black hole masses, which are expected to be lower than those of the SDSS because the quasars have lower luminosity. The GNIRS spectra will also be used to determine if the quasars are dust-reddened and to find the extinction law of this dust.