2018MNRAS.481..122C

We have used integral field spectroscopy to study the internal kinematics of the H II galaxies CTS 1020 and UM 461. We based our analysis on the velocity and velocity dispersion maps, and intensity-velocity dispersion (I-σ) and velocity-velocity dispersion (V_r-σ) diagrams. We found that the motion in both star-forming knots of UM 461 has different patterns, suggesting a weak kinematical connection between the knots. The overall kinematics of the galaxy is probably affected by stellar feedback. CTS 1020 has an ordered motion with a gradient compatible with a disc rotating at ∼50 km s^–1, though the velocity field is disturbed. In both galaxies the highest and lowest σ values are distributed in the outer parts and are associated with the diffuse gas that permeates the galaxies. UM 461 has a ring-like structure with small regions of increasing σ in the eastern knot, which resemble what we could expect in a collect and collapse scenario of star formation. We found that UM 461 seems to be more susceptible to stellar feedback, whereas in CTS 1020 the gravitational potential dominates.