Fig. 1: Spectral features of SNR 0509, showing coronal lines and Balmer emission.
From: Calcium in a supernova remnant as a fingerprint of a sub-Chandrasekhar-mass explosion
A spectrum extracted from a region on the western side of SNR 0509 (region inside the right white rectangle in Fig. 2). Seen are broad coronal lines of different ionization states of iron, calcium and sulfur (and possibly nickel) from the reverse shocked ejecta as well as broad and narrow Balmer lines from the forward shock. The gap in the spectrum at around 589 nm stems from the MUSE notch filter used to block the residual laser light from the 4LGSF system (see ‘Observations and data reduction’ section in Methods). λ, wavelength.
