High-Resolution X-ray imaging and spectroscopy of N 103B

The X-ray emission from the young supernova remnant (SNR) N 103B is measured and analysed using the high-resolution cameras and spectrometers on board XMM-Newton and Chandra. The spectrum from the entire remnant is reproduced very well with three plasma components of kT_e = 0.55, 0.65, and 3.5 keV, corresponding roughly to line emission by the O-K, Fe-L, and Fe-K species, respectively. Narrow band images reveal different morphologies for each component. The kT_e = 0.65 keV component, which dominates the emission measure (4.5*E⁶⁵ m^-3), is in ionisation equilibrium. This provides a lower limit of 1200 yrs to the age of the remnant, which is in agreement with the previously assumed age of the remnant (1500 yrs). Based on the measured energy of the Fe-K feature at 6.5 keV, the hot (3.5 keV) component is found to be recently shocked ( ~ 200 yrs) and still ionising. The high elemental abundances of O and Ne and the low abundance of Fe could imply that N 103B originated from a type II supernova (SN) rather than a type Ia SN as previously thought.