A Deep Survey of Fields around $z>4$ Quasars

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Session 78 -- QSOs and Gravitational Lenses
Oral presentation, Thursday, 2:30-4:00, Durham Room

[78.02] A Deep Survey of Fields around $z>4$ Quasars

E. Egami, E. Hu (Institute for Astronomy, University of Hawaii)

As another approach to detect a population of high-$z$ galaxies, we have been undertaking a deep survey of fields around $z>4$ quasars, trying to find galaxies associated with these quasars at quasars' redshifts. We shall present the preliminary results of this survey.

This survey consists of deep imaging around five $z>4$ quasars in the B, I, and K band. The survey area per field is $90^{2}$ arcsec$^{2}$, which is limited by the small size of IR array. This survey has the following advantages over the previous studies:

\begin{itemize} \item The sample is selected in the K band, in which light suffers less obscuration by dust. \item Quasars at $z>4$ are expected to reside in exceptionally high peaks of density, which implies strong clustering of galaxies around those quasars. Therefore, we can expect a larger possibility of finding galaxies around them. \item At redshifts larger than 4, the Lyman continuum break at 912 $\AA$ falls longward of the B band. Therefore, galaxies at such high redshifts can be discriminated by abrupt drop in flux at the B band. \end{itemize}

Our results will be statistically compared with the results from Hawaii Blank-Sky Deep Survey (Cowie et.\ al.). Also, preliminary results from follow-up multi-slit spectroscopy done for one of the fields will be discussed.

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