The Fundamental Plane of Massive Quiescent Galaxies Out to z ~ 2
Abstract
The Fundamental Plane (FP) of early-type galaxies, relating the effective radius, velocity dispersion, and surface brightness, has long been recognized as a unique tool for analyzing galaxy structure and evolution. With the discovery of distant quiescent galaxies and the introduction of high sensitivity near-infrared spectrographs, it is now possible to explore the FP out to z ~ 2. In this Letter we study the evolution of the FP out to z ~ 2 using kinematic measurements of massive quiescent galaxies (M * > 1011 M ⊙). We find preliminary evidence for the existence of an FP out to z ~ 2. The scatter of the FP, however, increases from z ~ 0 to z ~ 2, even when taking into account the larger measurement uncertainties at higher redshifts. We find a strong evolution of the zero point from z ~ 2 to z ~ 0: Δlog10 M/Lg vprop(- 0.49 ± 0.03)z. In order to assess whether our spectroscopic sample is representative of the early-type galaxy population at all redshifts, we compare their rest-frame g - z colors with those from a larger mass complete sample of quiescent galaxies. At z > 1 we find that the spectroscopic sample is bluer. We use the color offsets to estimate a mass-to-light ratio (M/L) correction. The implied FP zero point evolution after correction is significantly smaller: Δlog10 M/Lg vprop(- 0.39 ± 0.02)z. This is consistent with an apparent formation redshift of zform=6.62+3.19-1.44 for the underlying population, ignoring the effects of progenitor bias. A more complete spectroscopic sample is required at z ~ 2 to properly measure the M/L evolution from the FP evolution.
- Publication:
-
The Astrophysical Journal
- Pub Date:
- October 2014
- DOI:
- 10.1088/2041-8205/793/2/L31
- arXiv:
- arXiv:1409.2492
- Bibcode:
- 2014ApJ...793L..31V
- Keywords:
-
- galaxies: evolution;
- galaxies: formation;
- galaxies: kinematics and dynamics;
- galaxies: stellar content;
- galaxies: structure;
- Astrophysics - Astrophysics of Galaxies;
- Astrophysics - Cosmology and Nongalactic Astrophysics
- E-Print:
- Accepted for publication in ApJ, 6 pages, 3 figures, 1 table