We present a new analysis of the deuterium absorption at z = 2.504 towards the quasar Q1009+2956 using the mesoturbulent model which accounts for possible correlations in the large scale velocity field .
We obtain a slightly higher deuterium-to-hydrogen ratio D/H \simeq ( 3.5 - 5.0 ) \times 10 ^ { -5 } as compared with the recent measurement D/H = ( 3.3 - 4.5 ) \times 10 ^ { -5 } ( 68 % C.L . )
performed by Burles & Tytler ( 1998b ) using the usual microturbulent approximation which assumes that the velocity field is uncorrelated .
Other mesoturbulent calculations of the D-abundances at z = 3.572 towards Q1937–1009 and at z = 0.701 towards Q1718+4807 ( the systems showing ‘ low ’ and possibly ‘ high ’ D/H values , respectively , in the microturbulent approaches ) agree with the present one within the errors of measurements .
Thus , the mesoturbulent analysis does not reveal any spatial variations of D/H and supports the standard homogeneous model of big bang nucleosynthesis .