| Abstract | The paper deals with observations of neutral hydrogen in the south-west of the Andromeda Nebula (M31) at a resolution of 0.8 x 1.2 arcmin. It is shown that much of the neutral hydrogen forms long narrow arm-like segments, which are resolved by the telescope beam and are separated by several times their widths, except near the minor axis. An optical depth of 0.22 is found in the direction of the continuum source, 5C3.107, implying that the H I spin temperature is approximately 220 K. Except in a few areas where brightness temperatures exceed 60 K, self-absorption is not significant. |
