We present spatially-resolved two-dimensional stellar kinematics for the 41 most massive early-type galaxies (M K −25.7 mag, stellar mass M * 10 11.8 M ) of the volume-limited (D < 108 Mpc) MASSIVE survey. For each galaxy, we obtain highquality spectra in the wavelength range of 3650 to 5850Å from the 246-fiber Mitchell integral-field spectrograph (IFS) at McDonald Observatory, covering a 107 × 107 field of view (often reaching 2 to 3 effective radii). We measure the 2-D spatial distribution of each galaxy's angular momentum (λ and fast or slow rotator status), velocity dispersion (σ), and higher-order non-Gaussian velocity features (Gauss-Hermite moments h 3 to h 6 ). Our sample contains a high fraction (∼ 80%) of slow and non-rotators with λ 0.2. When combined with the lower-mass ETGs in the ATLAS 3D survey, we find the fraction of slow-rotators to increase dramatically with galaxy mass, reaching ∼ 50% at M K ∼ −25.5 mag and ∼ 90% at M K −26 mag. All of our fast rotators show a clear anti-correlation between h 3 and V /σ, and the slope of the anti-correlation is steeper in more round galaxies. The radial profiles of σ show a clear luminosity and environmental dependence: the 12 most luminous galaxies in our sample (M K −26 mag) are all brightest cluster/group galaxies (except NGC 4874) and all have rising or nearly flat σ profiles, whereas five of the seven "isolated" galaxies are all fainter than M K = −25.8 mag and have falling σ. All of our galaxies have positive average h 4 ; the most luminous galaxies have average h 4 ∼ 0.05 while less luminous galaxies have a range of values between 0 and 0.05. Most of our galaxies show positive radial gradients in h 4 , and those galaxies also tend to have rising σ profiles. We discuss the implications for the relationship among dynamical mass, σ, h 4 , and velocity anisotropy for these massive galaxies.

We analyse the environmental properties of 370 local early-type galaxies (ETGs) in the MASSIVE and ATLAS 3D surveys, two complementary volume-limited integralfield spectroscopic (IFS) galaxy surveys spanning absolute K-band magnitude −21.5 > ∼ M K > ∼ − 26.6, or stellar mass 8 × 10 9 < ∼ M * < ∼ 2 × 10 12 M . 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 λ e and enable us to examine the relationship among λ e , M * , and galaxy environment. We find a strong correlation between λ e and M * , where the average λ e decreases from ∼ 0.4 to below 0.1 with increasing mass, and the fraction of slow rotators f slow increases from ∼ 10% to 90%. 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.

We use spatially resolved two-dimensional stellar velocity maps over a 107 × 107 field of view to investigate the kinematic features of 90 early-type galaxies above stellar mass 10 11.5 M in the MASSIVE survey. We measure the misalignment angle Ψ between the kinematic and photometric axes and identify local features such as velocity twists and kinematically distinct components. We find 46% of the sample to be well aligned (Ψ < 15 • ), 33% misaligned, and 21% without detectable rotation (nonrotators). Only 24% of the sample are fast rotators, the majority of which (91%) are aligned, whereas 57% of the slow rotators are misaligned with a nearly flat distribution of Ψ from 15 • to 90 • . 11 galaxies have Ψ 60 • and thus exhibit minor-axis ("prolate") rotation in which the rotation is preferentially around the photometric major axis. Kinematic misalignments occur more frequently for lower galaxy spin or denser galaxy environments. Using the observed misalignment and ellipticity distributions, we infer the intrinsic shape distribution of our sample and find that MASSIVE slow rotators are consistent with being mildly triaxial, with mean axis ratios of b/a = 0.88 and c/a = 0.65. In terms of local kinematic features, 51% of the sample exhibit kinematic twists of larger than 20 • , and 2 galaxies have kinematically distinct components. The frequency of misalignment and the broad distribution of Ψ reported here suggest that the most massive early-type galaxies are mildly triaxial, and that formation processes resulting in kinematically misaligned slow rotators such as gas-poor mergers occur frequently in this mass range.

We measure the radial profiles of the stellar velocity dispersions, σ(R), for 90 early-type galaxies (ETGs) in the MASSIVE survey, a volume-limited integral-field spectroscopic (IFS) galaxy survey targeting all northern-sky ETGs with absolute K-band magnitude M K < −25.3 mag, or stellar mass M * > ∼ 4 × 10 11 M , within 108 Mpc. Our wide-field 107 ×107 IFS data cover radii as large as 40 kpc, for which we quantify separately the inner (2 kpc) and outer (20 kpc) logarithmic slopes γ inner and γ outer of σ(R). While γ inner is mostly negative, of the 56 galaxies with sufficient radial coverage to determine γ outer we find 36% to have rising outer dispersion profiles, 30% to be flat within the uncertainties, and 34% to be falling. The fraction of galaxies with rising outer profiles increases with M * and in denser galaxy environment, with 10 of the 11 most massive galaxies in our sample having flat or rising dispersion profiles. The strongest environmental correlations are with local density and halo mass, but a weaker correlation with large-scale density also exists. The average γ outer is similar for brightest group galaxies, satellites, and isolated galaxies in our sample. We find a clear positive correlation between the gradients of the outer dispersion profile and the gradients of the velocity kurtosis h 4 . Altogether, our kinematic results suggest that the increasing fraction of rising dispersion profiles in the most massive ETGs are caused (at least in part) by variations in the total mass profiles rather than in the velocity anisotropy alone.

We measure the stellar populations as a function of radius for 90 early-type galaxies (ETGs) in the MASSIVE survey, a volume-limited integral-field spectroscopic (IFS) galaxy survey targeting all northern-sky ETGs with absolute K-band magnitude M K < −25.3 mag, or stellar mass M * 4 × 10 11 M , within 108 Mpc. We are able to measure reliable stellar population parameters for individual galaxies out to 10 − 20 kpc (1 − 3R e ) depending on the galaxy. Focusing on ∼ R e (∼ 10 kpc), we find significant correlations between the abundance ratios, σ, and M * at large radius, but we also find that the abundance ratios saturate in the highest-mass bin. We see a strong correlation between the kurtosis of the line of sight velocity distribution (h4) and the stellar population parameters beyond R e . Galaxies with higher radial anisotropy appear to be older, with metal-poorer stars and enhanced [α/Fe]. We suggest that the higher radial anisotropy may derive from more accretion of small satellites. Finally, we see some evidence for correlations between environmental metrics (measured locally and on > 5 Mpc scales) and the stellar populations, as expected if satellites are quenched earlier in denser environments.