High-resolution gas surface density map of M51 from the HST extinction method from Faustino Vieira et al. 2023 (pink), overlayed on the HST v-band (blue), and Halpha (yellow).
Image Credit: Helena Faustino Vieira (CHART, Cardiff University), NASA, ESA.
Top-down view of the time evolution of the Milky Way-like model from Duran-Camacho et al. 2025, over a period of 40Myrs. This movie is produced in the
referential of the bar (i.e. keeping the bar always along the x axis), and highlights the rapid changes of the spiral patterns (and their velocities) over time.
The different panels show: the gas surface densities (top-left), the gas radial velocities (top-centre), the gas tangential velocity residuals (top-right),
the volume density (bottom-left), the fraction of dense mass above a critical density of 700 cm-3 (bottom-centre), and the velocity divergence (bottom-right).
Credit: Eva Duran Camacho (IAC).