The Clustering of Faint Galaxies on Small Angular Scales

We present a preliminary measurement of the angular clustering of faint ($R \le 25$)fieldgalaxiesinwhichweconcentrateonthebehaviorof$w(\theta)$onsmallangularscales($\theta \ls 10’'$). The galaxies are strongly clustered and $w(\theta )$ is well-characterized by a power law of the form $A_w \theta^{-\delta}$\mathrm{.}Thebest-fittingvalueofthepowerlawindex,$\delta$, is, however, steeper than the fiducial value of $\delta =0.8$, indicating there are more pairs of galaxies separated by $\theta \text{ls}{10}^{\mathrm{\prime }\mathrm{\prime }}$ in our sample than would be otherwise expected. Using the best-fitting form of $w(\theta )$, we estimate that $\sim 10$ of the galaxies are in physically close pairs (separations $\text{ls}21h^{-1}$ kpc). This is a factor of order 2 larger than local galaxy samples, but comparable to galaxy samples with $<z>\sim 0.4$. The mean redshift of our galaxies is of order 0.95, and, therefore, our result suggests that there was little or no evolution in the merger rate of galaxies between $z\sim 1$ and $z\sim 0.4$.