The MASSIVE Survey – V. Spatially resolved stellar angular momentum, velocity dispersion, and higher moments of the 41 most massive local early-type galaxies

Abstract

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.

The Sami Galaxy Survey: Revisiting Galaxy Classification Through High-Order Stellar Kinematics

“…Veale et al (2017) also find positive h 4 values for 41 massive early-type galaxies in the MASSIVE survey, similar to the results presented here. This suggests that some physical effect could be responsible for our positive h 4 values, rather than residual template mismatch.…”

Clocking the formation of today’s largest galaxies: wide field integral spectroscopy of brightest cluster galaxies and their surroundings

“…Complicating this simple picture are the isolated, satellite and brightest group (BGG) galaxies observed by Veale et al (2017Veale et al ( , 2018 out to 20 − 40 kpc from the galaxy core. All types of galaxies are found to contain some fraction of rising, falling and flat velocity dispersion profiles.…”

“…Only A85 and A2634 remain falling beyond 1 r e , all other profiles are seen in the right panels of Figure 7 to rise past this point. Newman et al (2013) observe 7 BCGs at z = 0.2 − 0.3 to 1 − 2r e finding all 7 have rising velocity dispersion profiles, and recent spectroscopic surveys of the MASSIVE team (Veale et al 2017(Veale et al , 2018 and Loubser et al (2018) have likewise found a significant fraction of rising velocity dispersion profiles for BCGs. The MASSIVE survey is an IFU survey of massive red galaxies that covers a similar extent at a similar spatial resolution as the present study, but only includes a few BCGs.…”

LARgE Survey – II. The dark matter haloes and the progenitors and descendants of ultramassive passive galaxies at cosmic noon

“…The stellar mass of the central galaxy in the Virgo cluster, NGC 4486, is M =10 11.57 M (Forte et al 2013, using the Chabrier 2003. The stellar masses of the two central galaxies in the Coma cluster, NGC 4874 and NGC 4889, are 10 11.98 M and 10 12.18 M respectively (Veale et al 2017, independent of IMF). Since UMPEGs already have stellar masses > 10 11.4 M at z∼1.6 (i.e., 9.5 Gyr ago ;Wright 2006), it is plausible that they could become the massive central galaxies of low-z massive clusters with only moderate growth via, e.g., minor mergers.…”