The ATLAS3D project - V. The CO Tully-Fisher relation of early-type galaxies
Abstract
We demonstrate here using both single-dish and interferometric observations that CO molecules are an excellent kinematic tracer, even in high-mass galaxies, allowing us to investigate for the first time the CO Tully-Fisher relation (CO-TFR) of early-type galaxies. We compare the TFRs produced using both single-dish and interferometric data and various inclination estimation methods, and evaluate the use of the velocity profile shape as a criterion for selecting galaxies in which the molecular gas extends beyond the peak of the rotation curve. We show that the gradient and zero-point of the best-fitting relations are robust, independent of the velocity measure and inclination used, and agree with those of relations derived using stellar kinematics. We also show that the early-type CO-TFR is offset from the CO-TFR of spirals by 0.98 ± 0.22 mag at Ks band, in line with other results. The intrinsic scatter of the relation is found to be ≈0.4 mag, similar to the level found in the spiral galaxy population. Next-generation facilities such as the Large Millimeter Telescope and the Atacama Large Millimeter/Sub-millimeter Array should allow this technique to be used in higher redshift systems, providing a simple new tool to trace the mass-to-light ratio evolution of the most massive galaxies over cosmic time.
- Publication:
-
Monthly Notices of the Royal Astronomical Society
- Pub Date:
- June 2011
- DOI:
- 10.1111/j.1365-2966.2011.18284.x
- arXiv:
- arXiv:1102.4877
- Bibcode:
- 2011MNRAS.414..968D
- Keywords:
-
- ISM: kinematics and dynamics;
- galaxies: elliptical and lenticular;
- cD;
- galaxies: evolution;
- galaxies: kinematics and dynamics;
- galaxies: spiral;
- galaxies: structure;
- Astrophysics - Cosmology and Nongalactic Astrophysics
- E-Print:
- 17 pages, 7 figures, MNRAS accepted