The 2dF Galaxy Redshift Survey: galaxy clustering per spectral type

We have calculated the two-point correlation functions in redshift space, �(�,�), for galaxies of different spectral types in the 2dF Galaxy Redshift Survey. Using these correlation functions we are able to estimate values of the linear redshi ft-space distortion parameter, � ≡ 0.6 m /b, the pairwise velocity dispersion, a, and the real-space correlation function, �(r), for galaxies with both relatively low star-formation rates (for which the present rate of star formation is less than 10% of its past averaged value) and galaxies with higher current starformation activity. At small separations, the real-space c lustering of passive galaxies is very much stronger than that of the more actively star-forming galaxies; the correlation-function slopes are respectively 1.93 and 1.50, and the relative bias between the two classes is a declining function of radius. On scales larger than 10h 1 Mpc there is evidence that the relative bias tends to a constant, bpassive/bactive ≃ 1. This result is consistent with the similar degrees of redshift-space distortions seen in the correlation func tions of the two classes ‐ the contours