Calibrating Interstellar Abundances using SNR Radiative Shocks

Using integral field data we extract the optical spectra of shocked interstellar clouds in Kepler’s supernova remnant located in the inner regions of our Galaxy, as well as in the Large Magellanic Cloud (LMC), the Small Magellanic Cloud (SMC), NGC6822 and IC 1613. Using self-consistent shock modelling, we make a new determination of the chemical composition of the interstellar medium (ISM) in N, O, Ne, S, Cl and Ar in these galaxies and obtain accurate estimates of the fraction of refractory grains destroyed in the shock. By comparing our derived abundances with those obtained in recent works using observations of B stars, F supergiant stars and HII regions, we provide a new calibration for abundance scaling in the range $7.9 \lesssim 12+\log {\mathrm {O/H}} \lesssim 9.1$.