A search for z ̃ 6 QSOS in the palomar-quest sky survey

Recently, the exploration of the earliest stages of galaxy and structure formation, and the timing of the cosmic reionization epoch have become some of the most active areas in cosmological research. In preparation for the advent of GTC and GTM, we are searching for QSOs around the end of the reionization era. These QSOs will be used as probes for the formation of the first massive structures and the early intergalactic medium (IGM). Such massive objects are rare at any epoch; hence, large areas of the sky have to be covered in order to generate statistical samples. The Palomar-Quest Synoptic Sky Survey (hereafter PQ) is a new major digital sky survey conducted at the Samuel Oschin 48-inch Schmidt telescope at Palomar. Color selection is an efficient way to select high-z objects. However, for z ≳ 5:5 or so, QSO candidate samples are heavily contaminated by late-M and brown dwarfs. Nevertheless, suitable candidates can be isolated with the aid of IR photometry. The INAOE team is using the 2.1-m Telescope at the Observatorio Astrofísico Guillermo Haro (OAGH) and the Cananea Near-Infrared Camera (CANICA) to obtain deep J-band images of PQ point sources seen as i0 drop-outs. Aside from the high-z QSO search proposed above, this project will also generate a large number of very low mass stars and brown dwarfs.