Kinematics of the Galactic supernova remnant G109.1-1.0 (CTB 109)

We present direct images in the Hα and [S II] λλ6717,6731 Å lines of the Galactic supernova remnant (SNR) G109.1-1.0 (CTB 109). We confirm that the filaments detected are the optical counterpart of the X-ray and radio SNR due to their high [S II]/H α line ratios. We study for the first time the kinematics of the optical counterpart of SNR CTB 109 using the Universidad Nacional Autónoma de México scanning Fabry-Perot interferometer PUMA. We estimate a systemic velocity of V_LSR = -50 ± 6 km s^-1 for this remnant and an expansion velocity of V_exp = 230 ± 5 km s^-1. From this velocity and taking into account previous studies of the kinematics of objects at that Galactic longitude, we derive a distance to SNR CTB 109 of 3.1 ± 0.2 kpc, locating it in the Perseus arm. Using the [S II] λ6717/[S II] λ6731 line ratio, we find an electronic density value around n_e = 580 cm^-3. Considering that this remnant is evolving in a low-density medium with higher-density cloudlets responsible for the optical emission, we determine the age and energy deposited in the ISM by the supernova explosion (E₀) in both the Sedov-Taylor phase and the radiative phase. For both cases, the age is thousands of years and E₀ is rather typical of SNRs containing simple pulsars, so that the energy released to the ISM cannot be used to distinguish between SNRs hosting typical pulsars from those hosting powerful magnetars, like CTB 109.