4 research outputs found
EMPRESS. IX. Extremely Metal-Poor Galaxies are Very Gas-Rich Dispersion-Dominated Systems: Will JWST Witness Gaseous Turbulent High-z Primordial Galaxies?
We present kinematics of 6 local extremely metal-poor galaxies (EMPGs) with
low metallicities () and low stellar masses
(). Taking deep medium-high resolution
() integral-field spectra with 8.2-m Subaru, we resolve the small
inner velocity gradients and dispersions of the EMPGs with H emission.
Carefully masking out sub-structures originated by inflow and/or outflow, we
fit 3-dimensional disk models to the observed H flux, velocity, and
velocity-dispersion maps. All the EMPGs show rotational velocities () of 5--23 km s smaller than the velocity dispersions
() of 17--31 km s, indicating dispersion-dominated () systems affected by inflow and/or outflow. Except
for two EMPGs with large uncertainties, we find that the EMPGs have very large
gas-mass fractions of . Comparing our results with
other H kinematics studies, we find that
decreases and increases with decreasing metallicity, decreasing
stellar mass, and increasing specific star-formation rate. We also find that
simulated high- () forming galaxies have gas fractions and dynamics
similar to the observed EMPGs. Our EMPG observations and the simulations
suggest that primordial galaxies are gas-rich dispersion-dominated systems,
which would be identified by the forthcoming James Webb Space Telescope (JWST)
observations at .Comment: Submitted to ApJ; After revisio
Improving land surface soil moisture and energy flux simulations over the Tibetan plateau by the assimilation of the microwave remote sensing data and the GCM output into a land surface model
EMPRESS. IX. Extremely Metal-Poor Galaxies are Very Gas-Rich Dispersion-Dominated Systems: Will JWST Witness Gaseous Turbulent High-z Primordial Galaxies?
Submitted to ApJWe present kinematics of 6 local extremely metal-poor galaxies (EMPGs) with low metallicities () and low stellar masses (). Taking deep medium-high resolution () integral-field spectra with 8.2-m Subaru, we resolve the small inner velocity gradients and dispersions of the EMPGs with H emission. Carefully masking out sub-structures originated by inflow and/or outflow, we fit 3-dimensional disk models to the observed H flux, velocity, and velocity-dispersion maps. All the EMPGs show rotational velocities () of 5--23 km s smaller than the velocity dispersions () of 17--31 km s, indicating dispersion-dominated () systems affected by inflow and/or outflow. Except for two EMPGs with large uncertainties, we find that the EMPGs have very large gas-mass fractions of . Comparing our results with other H kinematics studies, we find that decreases and increases with decreasing metallicity, decreasing stellar mass, and increasing specific star-formation rate. We also find that simulated high- () forming galaxies have gas fractions and dynamics similar to the observed EMPGs. Our EMPG observations and the simulations suggest that primordial galaxies are gas-rich dispersion-dominated systems, which would be identified by the forthcoming James Webb Space Telescope (JWST) observations at
EMPRESS. IX. Extremely Metal-Poor Galaxies are Very Gas-Rich Dispersion-Dominated Systems: Will JWST Witness Gaseous Turbulent High-z Primordial Galaxies?
Submitted to ApJWe present kinematics of 6 local extremely metal-poor galaxies (EMPGs) with low metallicities () and low stellar masses (). Taking deep medium-high resolution () integral-field spectra with 8.2-m Subaru, we resolve the small inner velocity gradients and dispersions of the EMPGs with H emission. Carefully masking out sub-structures originated by inflow and/or outflow, we fit 3-dimensional disk models to the observed H flux, velocity, and velocity-dispersion maps. All the EMPGs show rotational velocities () of 5--23 km s smaller than the velocity dispersions () of 17--31 km s, indicating dispersion-dominated () systems affected by inflow and/or outflow. Except for two EMPGs with large uncertainties, we find that the EMPGs have very large gas-mass fractions of . Comparing our results with other H kinematics studies, we find that decreases and increases with decreasing metallicity, decreasing stellar mass, and increasing specific star-formation rate. We also find that simulated high- () forming galaxies have gas fractions and dynamics similar to the observed EMPGs. Our EMPG observations and the simulations suggest that primordial galaxies are gas-rich dispersion-dominated systems, which would be identified by the forthcoming James Webb Space Telescope (JWST) observations at