The EDGE-CALIFA Survey: Evidence for Pervasive Extraplanar Diffuse Ionized Gas in Nearby Edge-on Galaxies
Year: 2019
Type: article
Abstract: We investigate the prevalence, properties, and kinematics of extraplanar diffuse ionized gas (eDIG) in a sample of 25 edge-on galaxies selected from the CALIFA survey. We measure ionized gas scale heights from H α and find that 90% have measurable scale heights with a median of kpc. From the H α kinematics, we find that 60% of galaxies show a decrease in the rotation velocity as a function of height above the midplane. This lag is characteristic of eDIG, and we measure a median lag of 21 km s −1 kpc −1 , which is comparable to lags measured in the literature. We also investigate variations in the lag with radius. H i lags have been reported to systematically decrease with galactocentric radius. We find both increasing and decreasing ionized gas lags with radius, as well as a large number of galaxies consistent with no radial lag variation, and investigate these results in the context of internal and external origins for the lagging ionized gas. We confirm that the [S ii ]/H α and [N ii ]/H α line ratios increase with height above the midplane as is characteristic of eDIG. The ionization of the eDIG is dominated by star-forming complexes (leaky H ii regions). We conclude that the lagging ionized gas is turbulent ejected gas likely resulting from star formation activity in the disk as opposed to gas in the stellar thick disk or bulge. This is further evidence for the eDIG being a product of stellar feedback and for the pervasiveness of this WIM-like phase in many local star-forming galaxies.
Source: The Astrophysical Journal
Authors: Rebecca C. Levy, Alberto D. Bolatto, Sebastián F. Sánchez, Leo Blitz, Dario Colombo, Veselina Kalinova, Carlos López-Cobá, Eve C. Ostriker, Peter Teuben, Dyas Utomo, Stuart N. Vogel, Tony Wong
Language: English
Subfield: Astronomy and Astrophysics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: bronze
Funders: National Science Foundation, U.S. Department of Energy, Alfred P. Sloan Foundation, James S. McDonnell Foundation, Gordon and Betty Moore Foundation, Alexander von Humboldt-Stiftung, Yale University, Vanderbilt University, Princeton University, Ohio State University, California Institute of Technology, Harvard University, University of Chicago, University of Washington, Johns Hopkins University, Carnegie Mellon University, University of Portsmouth, New Mexico State University, York University, Deutsche Forschungsgemeinschaft, Consejo Nacional de Ciencia y Tecnología, Office of Science, College of Engineering, Michigan State University, Graduate School, University of Maryland, Dirección General de Asuntos del Personal Académico, Universidad Nacional Autónoma de México, Brookhaven National Laboratory, Lawrence Berkeley National Laboratory
Awards: G1559670774, Collaborative Research: Astronomy with CARMA, The Role of Gas in the Evolution of Galaxies, Collaborative Research: Changes in Molecular Gas and Galaxy Properties Over Time in the Era of Integral Field Unit Surveys, G6298739341, G6990935076, Collaborative Research: Changes in Molecular Gas and Galaxy Properties Over Time in the Era of Integral Field Unit Surveys, G807229733, G8154828639, G8283437609, Collaborative Research: Changes in Molecular Gas and Galaxy Properties Over Time in the Era of Integral Field Unit Surveys, Collaborative Research: Astronomy with CARMA
OpenAlex ID: W2971627727