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We measure the evolution of the correlation between black hole mass and host spheroid velocity dispersion over the last 6 billion years, by studying three carefully selected samples of active galaxies at z=0. 57, z=0. 36 and z<0. 1. For all three samples, virial black hole masses are consistently estimated using the line dispersion of H and the continuum luminosity at 5100A or Halpha line luminosity, based on our cross calibration of the broad line region size-luminosity relation. For the z=0. 57 sample, new stellar velocity dispersions are measured from high signal-to-noise ratio spectra obtained at the Keck Telescope, while for the two lower redshift samples they are compiled from previous works. Extending our previous result at z=0. 36, we find an offset from the local relation, suggesting that for fixed M₁₇, distant spheroids have on average smaller velocity dispersions than local ones. The measured offset at z=0. 57 is d log sigma*=0. 12 0. 05 0. 06 (or d log M₁₇=0. 50 0. 22 0. 25), i. e. d log M₁₇ = (3. 11. 5) (1+z) + 0. 050. 21. This is inconsistent with a tight and non-evolving universal M-sigma relation at the 95%CL
Woo et al. (Thu,) studied this question.