the frequency range of the survey. This transition in turn consists of two spin-rotation fine structure components, which in turn are further split into several hyperfine components due to the nuclear spin of the hydrogen (C$_2$H) or nitrogen (CN) nucleus. Some of the hyperfine components which are blended in the spectrum of IRC+10216 are closer in frequency than half the linewidth, which is given by the terminal expansion velocity of the envelope (14.5 km s$^{-1}$; [@cer2000] 2000), implying that the emission at $V_{\rm LSR}=V_{\rm sys}$ for one component is contaminated by blue- or red-shifted emission from the overlapping component. These components are therefore not adequate to trace the spatial distribution of C$_2$H or CN in the plane of the sky. In the top left panel of Fig. \[fig:map\_all\] we show the spatial distribution of C$_2$H through a map of the $J=3/2-1/2$ $F=1-0$ component, lying at 87328.625 MHz, which is the most intense free of blending component. In this map the synthesized beam is $1{\mbox{\rlap{.}$''$}}07\times0{\mbox{\rlap{.}$''$}}92$ and the rms per 3 km s$^{-1}$ channel is 0.4 mJy beam$^{-1}$. In the case of CN, there are various intense non-overlapping components that show similar brightness distributions. The spatial distribution of CN is illustrated in 