We analyse the environmental properties of 370 local early-type galaxies (ETGs) in the MASSIVE and ATLAS^3D^ surveys, two complementary volume-limited integral-field spectroscopic (IFS) galaxy surveys spanning absolute K-band magnitude - 21.5>=M_K_>=-26.6, or stellar mass 810^9^<~M<~210^12^M{sun}. We find these galaxies to reside in a diverse range of environments measured by four methods: group membership (whether a galaxy is a brightest group/cluster galaxy, satellite or isolated), halo mass, large-scale mass density (measured over a few Mpc) and local mass density (measured within the Nth neighbour). The spatially resolved IFS stellar kinematics provide robust measurements of the spin parameter {lambda}e and enable us to examine the relationship among {lambda}e, M and galaxy environment. We find a strong correlation between {lambda}e and M, where the average {lambda}e decreases from ~0.4 to below 0.1 with increasing mass, and the fraction of slow rotators f_slow_ increase from ~10 to 90 per cent. We show for the first time that at fixed M, there are almost no trends between galaxy spin and environment; the apparent kinematic morphology-density relation for ETGs is therefore primarily driven by M and is accounted for by the joint correlations between M and spin, and between M* and environment. A possible exception is that the increased f_slow_ at high local density is slightly more than expected based only on these joint correlations. Our results suggest that the physical processes responsible for building up the present-day stellar masses of massive galaxies are also very efficient at reducing their spin, in any environment.

Cone search capability for table J/MNRAS/471/1428/tablea1 (Properties of MASSIVE survey galaxies)