The MASSIVE Survey – XII Connecting Stellar Populations of Early-Type Galaxies to Kinematics and Environment. (arXiv:1901.01271v1 [astro-ph.GA])

The MASSIVE Survey – XII Connecting Stellar Populations of Early-Type Galaxies to Kinematics and Environment. (arXiv:1901.01271v1 [astro-ph.GA])
<a href="http://arxiv.org/find/astro-ph/1/au:+Greene_J/0/1/0/all/0/1">Jenny E Greene</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Veale_M/0/1/0/all/0/1">Melanie Veale</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Ma_C/0/1/0/all/0/1">Chung-Pei Ma</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Thomas_J/0/1/0/all/0/1">Jens Thomas</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Quenneville_M/0/1/0/all/0/1">Matthew E. Quenneville</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Blakeslee_J/0/1/0/all/0/1">John P. Blakeslee</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Walsh_J/0/1/0/all/0/1">Jonelle L. Walsh</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Goulding_A/0/1/0/all/0/1">Andrew Goulding</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Ito_J/0/1/0/all/0/1">Jennifer Ito</a>

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* 4x10^11 M_sun, within 108 Mpc. We are able to measure reliable stellar population parameters for individual galaxies out to 10-20 kpc (1-3 R_e) depending on the galaxy. Focusing on ~R_e (~10 kpc), we find significant correlations between the abundance ratios, sigma, 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 [alpha/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.

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_sun, within 108
Mpc. We are able to measure reliable stellar population parameters for
individual galaxies out to 10-20 kpc (1-3 R_e) depending on the galaxy.
Focusing on ~R_e (~10 kpc), we find significant correlations between the
abundance ratios, sigma, 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 [alpha/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.

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