The 7 s X-ray pulsar 1E 2259+586 and the supernova remnant ( SNR ) G109.1 - 1.0 ( CTB 109 ) were observed by BeppoSAX in 1996 November .
The pulse period of 6.978914 \pm 0.000006 s implies that 1E 2259+586 continues its near constant spin-down trend .
The 0.5–10 keV pulse shape is characterized by a double peaked profile , with the amplitude of the second peak \sim 50 % of that of the main peak .
The pulse profile does not exhibit any strong energy dependence .
We confirm the ASCA discovery of an additional low-energy spectral component from 1E 2259+586 .
This can best be modeled as a 0.44 keV blackbody , but we can not exclude that some , or all , of this emission arises from the part of the SNR that lies within the pulsar ’ s extraction region .

The spectrum of G109.1 - 1.0 is well fit with a non-equilibrium ionization plasma model with a best-fit temperature of 0.95 keV .
The derived mass for the X-ray emitting plasma ( \sim 15–20 M _ { \odot } ) and its near cosmic abundances imply that the X-ray emission comes mainly from mildly enriched , swept-up circumstellar material .
The spectrum is strongly out of equilibrium with an ionization age of only 3000 yr .
This age is in good agreement with that derived from hydrodynamic simulations of the SNR using the above X-ray temperature .