Study of the progenitor of the magnetar 1E 2259+586 through Suzaku observations of the associated supernova remnant CTB 109.

We present a study of the progenitor of the magnetar 1E 2259+586, from Suzaku observations of the associated supernova remnant CTB 109. The Suzaku spectra, either spatially integrated or spatially resolved, were successfully described by a two-component plasma model, which reconfirms a previous Chandra result on the northwestern part of this remnant (Sasaki et al. 2013, A&A, 552, A45). The hotter component, with a temperature of ~0.7 keV, can be identified as the stellar ejecta heated by reverse shock, because its contribution increases towards the remnant center. The cooler one, with a temperature of ~0.25 keV, can be identified as the shocked interstellar matter. The abundances of Ne, Mg, Si, and S of the hotter component support these identifications. The total masses of the cooler and hotter components are estimated to be 220±40M⊙ and 42±11M⊙, respectively. The remnant is considered to be adiabatically expanding as in the Sedov- Taylor phase. The explosion energy, estimated to be 1.0 × 10⁵¹ erg by a canonical Sedov model, is typical of a core-collapse supernova explosion. Assuming that the hotter component includes the ejecta as well as the matter lost by the progenitor star via stellar winds, 1E 2259+586 is inferred to have originated from a very massive star. [ABSTRACT FROM AUTHOR]