Interaction of the supernova remnant S 147 with the ambient interstellar gas

Based on RATAN-600 21-cm H I line observations with an angular resolution of 2.4', we studied the neutral-hydrogen distribution in the region of the supernova remnant (SNR) S 147 (G180.0-1.7). We detected a rotating shell of neutral gas immediately adjacent to the SNR that is expanding at a velocity of 20 km s^?1. The H I shell is less distinct in the southeastern part and at negative radial velocities. The outer shell diameter is 90 pc; the H I mass in the shell is 2.2 × 10⁴M_⊙. These data allowed us to estimate the SNR age, 6.5×10⁵ yr, and the initial explosion energy, 2.2×10⁵¹ erg.