The BTC40 Survey for high-redshift quasars is a multicolor search using images obtained with the Big Throughput Camera (BTC) on the CTIO 4-m telescope in V, I, and z filters to search for quasars at redshifts of 4.8 < z < 6. The survey covers 40 sq. deg. in B, V, & I and 36 sq. deg. in z. Limiting magnitudes (3 sigma) reach to V = 24.6, I = 22.9 and z = 22.9. We used the (V-I) vs. (I-z) two-color diagram to select high-redshift quasar candidates from the objects classified as point sources in the imaging data. Follow-up spectroscopy with the AAT and CTIO 4-m telescopes of candidates having I < 21.5 has yielded two quasars with redshifts of z = 4.6 and z = 4.8 as well as four emission line galaxies with z = 0.6. Fainter candidates have been identified down to I = 22 for future spectroscopy on 8-m class telescopes.
@article{arxiv.astro-ph/0209055,
title = {The BTC40 Survey for Quasars at 4.8 < z < 6},
author = {E. M. Monier and J. D. Kennefick and P. B. Hall and P. S. Osmer and M. G. Smith and G. B. Dalton and R. F. Green},
journal= {arXiv preprint arXiv:astro-ph/0209055},
year = {2009}
}
Comments
27 pages, 8 figures; Accepted for publication in the Astronomical Journal