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

TL;DR

This study provides detailed kinematic analysis of the Galactic SNR G109.1-1.0 (CTB 109), estimating its velocity, distance, density, age, and explosion energy, confirming its optical and X-ray/radio counterparts and placing it in the Perseus arm.

Contribution

First-time kinematic measurements of CTB 109 using Fabry-Perot interferometry, deriving its systemic velocity, expansion velocity, distance, density, and energy estimates.

Findings

Systemic velocity V_LSR = -50 ± 6 km/s

Expansion velocity V_exp = 230 ± 5 km/s

Distance to SNR = 3.1 ± 0.2 kpc

Abstract

We present direct images in the H$\alpha$ and [SII]$\lambda \lambda$6717,6731 $\text{\AA}$ lines of the Galactic Supernova Remnant G109.1-1.0 (CTB 109). We confirm that the filaments detected are the optical counterpart of the X-ray and radio supernova remnant due to their high [SII]/H$\alpha$ line-ratios. We study for the first time the kinematics of the optical counterpart of SNR CTB 109 using the UNAM scanning Fabry-Perot interferometer PUMA. We estimate a systemic velocity of V$_{LSR}$=-50$\pm$6 km s$^{-1}$ for this remnant and an expansion velocity of V$_{exp}$=230$\pm$5 km s$^{-1}$. From this velocity value and taking into account previous studies about the kinematics of objects at that Galactic longitude we derive a distance to the SNR CTB 109 of 3.1$\pm$0.2 kpc, locating it in the Perseus arm. Using the [SII]$\lambda$6717/[SII]$\lambda$6731 line-ratio we find an electronic density value around n$_e$= 580 cm$^{-3}$. Considering that this remnant is evolving in a low density medium with higher density cloudlets responsible of the optical emission, we determine the age and energy deposited in the ISM by the supernova explosion (E$_0$) in both the Sedov-Taylor phase and the radiative phase. For both cases the age is of thousands of years and the E$_0$ is rather typical of SNRs containing simple pulsars so that, the energy released to the ISM cannot be used to distinguish between supernova remnants hosting typical pulsars from those hosting powerful magnetars as in the case of CTB 109.