Channel maps showing the convolved H i data subtracted from the GBT H i data for NGC 6946, its companions, and the H i filament. Contours are at −10σ, −5σ, −3σ, −2σ, 2σ, 3σ, 5σ, 10σ, 25σ, 50σ, 100σ, and 200σ, where σ = 8 mJy beam ⁻¹. The grayscale has units of mJy/GBT beam.