Vol. 567
In section 4. Extragalactic astronomy

The Mice at play in the CALIFA survey: A case study of a gas-rich major merger between first passage and coalescence

by V. Wild, F. Rosales-Ortega, J. Falcon-Barroso, et al. A&A 567, A132


New optical 3D-spectroscopy of the Mice, an ongoing merger between two massive gas-rich spirals, provides better knowledge of stellar and gas kinematics, ionized gas properties, and stellar population diagnostics, with 1.6 kpc spatial resolution. Although the merger-induced star formation has not yet contributed significantly to the stellar mass of the galaxies, the impact of the galaxy interaction is already important: distortions and twists of the stellar and ionized gas disk, induced formation of strong bars, and gas streaming motions. In addition, both galaxies show bicones of high-ionization gas extending along their minor axes. This corresponds to nuclear gas outflows, which are superwinds driven by either the starburst or the active galaxy nuclei (Seyfert-like), proving that feedback is in action.