ALBERT

Description: How a galaxy regulates its supernovae (SNe) energy into different interstellar/circumgalactic medium components strongly affects galaxy evolution. Based on the JVLA D-configuration C- (6 GHz) and L -band (1.6 GHz) continuum observations, we perform statistical analysis comparing multiwavelength properties of the Continuum Haloes in Nearby Galaxies – an EVLA Survey galaxies. The high-quality JVLA data and edge-on orientation enable us for the first time to include the halo into the energy budget for a complete radio-flux-limited sample. We find tight correlations of L radio with the mid-IR-based star formation rate (SFR). The normalization of our I 1.6 GHz /W Hz –1 –SFR relation is ~2–3times of those obtained for face-on galaxies, probably a result of enhanced IR extinction at high inclination. We also find tight correlations between L radio and the SNe energy injection rate $\dot{E}_{\rm SN(Ia+CC)}$ , indicating the energy loss via synchrotron radio continuum accounts for ~1 of $\dot{E}_{\rm SN}$ , comparable to the energy contained in cosmic ray electrons. The integrated C -to- L -band spectral index is α ~ 0.5–1.1 for non-active galactic nucleus galaxies, indicating a dominance by the diffuse synchrotron component. The low-scatter L radio –SFR/ $L_{\rm radio}\text{-}\dot{E}_{\rm SN (Ia+CC)}$ relationships have superlinear logarithmic slopes at ~2 in L band (1.132 ± 0.067/1.175 ± 0.102) while consistent with linear in C band (1.057 ± 0.075/1.100 ± 0.123). The superlinearity could be naturally reproduced with non-calorimeter models for galaxy discs. Using Chandra halo X-ray measurements, we find sublinear L X – L radio relations. These results indicate that the observed radio halo of a starburst galaxy is close to electron calorimeter, and a galaxy with higher SFR tends to distribute an increased fraction of SNe energy into radio emission (than X-ray).