The low-order kinematic moments of galaxies , namely bulk flow and shear , enables us to test whether theoretical models can accurately describe the evolution of the mass density field in the nearby Universe .
We use the so-called \eta MLE maximum likelihood estimator in log-distance space to measure these moments from a combined sample of the 2MASS Tully-Fisher ( 2MTF ) survey and the cosmicflows-3 ( CF3 ) compilation .
Galaxies common between 2MTF and CF3 demonstrate a small zero-point difference of -0.016 \pm 0.002 dex .
We test the \eta MLE on 16 mock 2MTF survey catalogues in order to explore how well the \eta MLE recovers the true moments , and the effect of sample anisotropy .
On the scale size of 37 h ^ { -1 } Mpc , we find that the bulk flow of the local Universe is 259 \pm 15 km s ^ { -1 } in the direction is ( l,b ) = ( 300 \pm 4 ^ { \circ } , 23 \pm 3 ^ { \circ } ) ( Galactic coordinates ) .
The average shear amplitude is 1.7 \pm 0.4 h km s ^ { -1 } Mpc ^ { -1 } .
We use a variable window function to explore the bulk and shear moments as a function of depth .
In all cases , the measurements are consistent with the predictions of the \Lambda cold dark matter ( \Lambda CDM ) model .