The Interaction between the Supernova Remnant W41 and the Filamentary Infrared Dark Cloud G23.33-0.30

Abstract

Abstract G23.33-0.30 is a 600 M ⊙ infrared dark molecular filament that exhibits large NH3 velocity dispersions (σ ∼ 8 km s−1) and bright, narrow NH3(3, 3) line emission. We have probed G23.33-0.30 at the < 0.1 pc scale and confirmed that the narrow NH3(3, 3) line is emitted by four rare NH3(3, 3) masers, which are excited by a large-scale shock impacting the filament. G23.33-0.30 also displays a velocity gradient along its length, a velocity discontinuity across its width, shock-tracing SiO(5–4) emission extended throughout the filament, and broad turbulent line widths in NH3(1, 1) through (6, 6), CS(5–4), and SiO(5–4), as well as an increased NH3 rotational temperature (T rot) and velocity dispersion (σ) associated with the shocked, blueshifted component. The correlations among T rot, σ, and V LSR imply that the shock is accelerating, heating, and adding turbulent energy to the filament gas. Given G23.33-0.30's location within the giant molecular cloud G23.0-0.4, we speculate that the shock and NH3(3, 3) masers originated from the supernova remnant (SNR) W41, which exhibits additional evidence of an interaction with G23.0-0.4. We have also detected the 1.3 mm dust continuum emission from at least three embedded molecular cores associated with G23.33-0.30. Although the cores have moderate gas masses (M = 7–10 M ⊙), their large virial parameters (α = 4–9) suggest that they will not collapse to form stars. The turbulent line widths of the (α > 1) cores may indicate negative feedback due to the SNR shock.