Tentative detection of galaxy spin correlations in the Tully catalog

We report a tentative detection of spin correlations in the Tully catalog o f nearby galaxies. We define a simple but nontrivial spin correlation funct ion and find an analytic estimate of it in the frame of the linear perturba tion theory. Then we present the observed spin correlation signal from the Tully galaxies with error bars. The three-dimensional spin correlation turn s out to be significant at the 97% confidence level, detected out to a few h(-1) Mpc. This observed correlation is consistent with the theoretical pre diction based on the gravitational instability picture of galaxy formation. An analysis of systematic errors is also presented. The observed strength of correlation may be sufficient to significantly affect the blank field of weak-lensing searches.