The MASSIVE Survey XIV—Stellar Velocity Profiles and Kinematic Misalignments from 200 pc to 20 kpc in Massive Early-type Galaxies

Abstract

We use high spatial resolution stellar velocity maps from the Gemini GMOS integral-field spectrograph (IFS) and wide-field velocity maps from the McDonald Mitchell IFS to study the stellar velocity profiles and kinematic misalignments from ∼ 200 pc to ∼ 20 kpc in 20 early-type galaxies with stellar mass M * > 10 11.7 M in the MASSIVE survey. While 80% of the galaxies have low spins (λ < 0.1) and low rotational velocities (< 50 km s −1 ) in both the central region and the main body, we find a diverse range of velocity features and misalignment angles. For the 18 galaxies with measurable central kinematic axes, 10 have well aligned kinematic axis and photometric major axis, and the other 8 galaxies have misalignment angles that are distributed quite evenly from 15 • to the maximal value of 90 • . There is a strong correlation between central kinematic misalignment and galaxy spin, where all 4 galaxies with significant spins have well aligned kinematic and photometric axes, but only 43% of the low-spin galaxies are well aligned. The central and main-body kinematic axes within a galaxy are not always aligned. When the two kinematic axes are aligned (∼ 60% of the cases), they are either also aligned with the photometric major axis or orthogonal to it. We find 13 galaxies to also exhibit noticeable local kinematic twists, and one galaxy to have a counter-rotating core. A diverse assembly history consisting of multiple gas-poor mergers of a variety of progenitor mass ratios and orbits is likely to be needed to account for the predominance of low spins and the wide range of central and main-body velocity features reported here for local massive ETGs.

Jet Collimation and Acceleration in the Giant Radio Galaxy NGC 315

“…We can also infer the sphere of influence of the black hole gravity via R SOI ≡ GM/σ 2 v (Peebles 1972), where σ v is the stellar velocity dispersion of the host bulge measured near the black hole. Ene et al (2020) obtained σ v ≈ 350 km s −1 at a radius of ≈ 0.1 arcsec in NGC 315, which gives R SOI ≈ 7.3 × 10 5 R g . These estimates suggest that the location of jet collimation break in NGC 315, z b ≈ (1.1 ± 0.2) × 10 5 R g , is an order of magnitude smaller than R B and R SOI , unlike M87 15 .…”

“…It hosts a Fanaroff-Riley Class I (FR I, Fanaroff & Riley 1974) radio source whose two-sided jets extend out to several hundred kpc from the galaxy (e.g., Bridle et al 1976;Laing et al 2006, see also Figure 1). Its large black hole mass of 1.6 × 10 9 M , estimated from the stellar velocity dispersion of σ v ≈ 350 km s −1 (Faber et al 1989;Ene et al 2020) and the latest M BH -σ v relation (Sexton et al 2019), makes it easier to resolve the putative jet collimation and acceleration region of this source.…”

Infrared Surface Brightness Fluctuation Distances for MASSIVE and Type Ia Supernova Host Galaxies*

“…The MASSIVE survey goal is to obtain a comprehensive census of all the major constituents-luminous and dark-of local galaxies in the highest-mass regime. To achieve these goals, the MASSIVE team has acquired extensive data using optical integral-field spectrographs (IFS) on both subarcsecond and arcminute scales and obtained uniform measurements of spatially resolved stellar kinematics (Veale et al 2017a(Veale et al , 2017b(Veale et al , 2018Ene et al 2018Ene et al , 2019Ene et al , 2020, stellar populations (Greene et al 2015(Greene et al , 2019, and ionized gas kinematics (Pandya et al 2017). They also obtained radio and X-ray data to investigate the properties of cold molecular gas (Davis et al 2016(Davis et al , 2019 and hot X-ray gas in these massive ETGs (Goulding et al 2016;Voit et al 2018).…”

The Hubble Constant from Infrared Surface Brightness Fluctuation Distances

“…The majority of the observations come from a program (GO-14219) to obtain SBF distances to all galaxies in the MASSIVE Survey priority sample (Ma et al 2014) out to 6000 km s −1 . MASSIVE is a volume-limited survey to study the structure, stellar populations, internal dynamics, and central black holes of the most massive early-type galaxies within 100 Mpc (e.g., Greene et al 2015;Veale et al 2018;Ene et al 2020;Liepold et al 2020). Uncertainties in supermassive black hole masses for nearby galaxies are often dominated by distance errors (Kormendy & Ho 2013).…”