The EDGE-CALIFA Survey: Molecular and Ionized Gas Kinematics in Nearby Galaxies

• Autores: Levy, Rebecca C.; Bolatto, Alberto; Teuben, Peter; Sánchez, Sebastián F.; Barrera Ballesteros, Jorge K.; Blitz, Leo; Colombo, Dario; García Benito, Rubén; Herrera Camus, Rodrigo; Husemann, Bernd; Kalinova, Veselina; Lan, Tian; Leung, Gigi Y. C.; Mast, Damian; Utomo, Dyas; Ven, Glenn van de; Vogel, Stuart N.; Wong, Tony
• Año de publicación: 2018
• Idioma: inglés
• Tipo de recurso: artículo
• Materia: GALAXIES: ISM; GALAXIES: KINEMATICS AND DYNAMICS; ISM: KINEMATICS AND DYNAMICS; ISM: MOLECULES
• Institución: Consejo Nacional de Investigaciones Científicas y Técnicas

We present a comparative study of molecular and ionized gas kinematics in nearby galaxies. These results are based on observations from the EDGE survey, which measured spatially resolved 12CO(J = 1-0) in 126 nearby galaxies. Every galaxy in EDGE has corresponding resolved ionized gas measurements from CALIFA. Using a sub-sample of 17 rotation-dominated, star-forming galaxies where precise molecular gas rotation curves could be extracted, we derive CO and Hα rotation curves using the same geometric parameters out to 1 R e. We find that ∼75% of our sample galaxies have smaller ionized gas rotation velocities than the molecular gas in the outer part of the rotation curve. In no case is the molecular gas rotation velocity measurably lower than that of the ionized gas. We suggest that the lower ionized gas rotation velocity can be attributed to a significant contribution from extraplanar diffuse ionized gas in a thick, turbulence-supported disk. Using observations of the Hγ transition, also available from CALIFA, we measure ionized gas velocity dispersions and find that these galaxies have sufficiently large velocity dispersions to support a thick ionized gas disk. Kinematic simulations show that a thick disk with a vertical rotation velocity gradient can reproduce the observed differences between the CO and Hα rotation velocities. Observed line ratios tracing diffuse ionized gas are elevated compared to typical values in the midplane of the Milky Way. In galaxies affected by this phenomenon, dynamical masses measured using ionized gas rotation curves will be systematically underestimated.
Fil: Levy, Rebecca C.. University of Maryland; Estados Unidos
Fil: Bolatto, Alberto. University of Maryland; Estados Unidos
Fil: Teuben, Peter. University of Maryland; Estados Unidos
Fil: Sánchez, Sebastián F.. Universidad Nacional Autónoma de México; México
Fil: Barrera Ballesteros, Jorge K.. University Johns Hopkins; Estados Unidos
Fil: Blitz, Leo. University of California at Berkeley; Estados Unidos
Fil: Colombo, Dario. Max Planck Institut Fur Radioastronomie; Alemania
Fil: García Benito, Rubén. Consejo Superior de Investigaciones Científicas; España
Fil: Herrera Camus, Rodrigo. Institut Max Planck fuer Gesellschaft. Max Planck Institute for Extraterrestrial Physics; Alemania
Fil: Husemann, Bernd. Max Planck Institut Fur Astronomie; Alemania
Fil: Kalinova, Veselina. Max Planck Institut Fur Radioastronomie; Alemania
Fil: Lan, Tian. University of Illinois; Estados Unidos. Columbia University; Estados Unidos
Fil: Leung, Gigi Y. C.. Max Planck Institut Fur Astronomie; Alemania
Fil: Mast, Damian. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba; Argentina. Universidad Nacional de Córdoba. Observatorio Astronómico de Córdoba; Argentina
Fil: Utomo, Dyas. Ohio State University; Estados Unidos. University of California at Berkeley; Estados Unidos
Fil: Ven, Glenn van de. European Southern Observatory; Alemania. Max Planck Institut Fur Astronomie; Alemania
Fil: Vogel, Stuart N.. University of Maryland; Estados Unidos
Fil: Wong, Tony. University of Illinois; Estados Unidos