We are studying the Central Molecular Zone (CMZ) in the inner few degrees
around the Galactic Centre, by mapping a large number of 3-mm molecular
lines. We have used the 22-m Mopra telescope, with the new
capabilities of the 8-GHz bandwidth MOPS digital filter bank. During 2006, we covered a 5 × 5 arcmin2 area of the
Sagittarius B2 molecular cloud complex, with spectral coverage of
nearly all of the range 81.7 to 113.5 GHz with 4 tunings of the
broad band mode. We imaged over 50 spectral lines with strong extended emission
and around 110 more lines which were weak, or concentrated at the Sgr B2(N) and
Sgr B2(M) cores (Jones et al. 2008). We find substantial differences in
chemical and physical conditions within the complex. During 2007 we covered the larger region of longitude -0.2 to 0.9 deg. and
latitude -0.20 to 0.12 deg., including Sgr A and Sgr B2, in the frequency range
85.3 to 91.3 GHz. This includes lines of C3H2, CH3CCH,
HOCO+, SO, H13CN, H13CO+, SO, HN13C, C2H, HNCO,
HCN, HCO+, HNC, HC3N, 13CS and N2H+.