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The chemical properties have been expected to be powerful astrophysical tools for the study of galaxies, because activity in the central regions of galaxies, such as a burst of massive star-formation or an active galactic nucleus (AGN), must have a strong impact on the chemical and physical properties of the surrounding interstellar medium (ISM). To date, several unbiased line surveys at mm/submm wavelengths have been reported towards the center of NGC 1068 (Snell et al. 2011; Costagliola et al. 2011; Kamenetzky et al. 2011; Spinoglio et al. 2012; Aladro et al. 2013) using single dish telescopes, but contamination from starbursts associated with inner spiral arms/ring could be a problem if we consider the sizes of the observing beams (14"-70"). On the other hand, interferometric imaging of the CND gives clean measurements of spectral lines, but the observed lines are limited to major species such as CO, HCN, HCO+, CS, CN, and SiO (e.g., Papadopoulos et al. 1996; Tacconi et al. 1997; Kohno et al. 2008; Garcia-Burillo et al. 2010; Krips et al. 2011) due to the limitation in sensitivity of the existing pre-ALMA mm/submm arrays.
In this situation, we proposed to observe several interesting molecules simultaneously in the 98 and 110 GHz regions sensitively with ALMA. These frequency regions are rich in molecules, including typical shock/dust related species and the CO isotopologues. We first obtained the intensities of such lines based on our line survey project with the 45m telescope (Nakajima et al. 2011). As an additional advantage of this frequency region, the primary beams of the ALMA 12m antennas (~1 arcmin) cover both the CND and the starburst ring in one field of view, which is useful for our purposes.
We present images and report a classification of molecular distributions into three main categories, defined as follows: (1) Molecules concentrated in the circumnuclear disk (CND) (SO J_N = 3_2-2_1, HC3N J = 11-10, 12-11, and CH3CN J_K = 6_K-5_K), (2) Molecules distributed both in the CND and the starburst ring (CS J = 2-1 and CH3OH J_K = 2_K-1_K), (3) Molecules distributed mainly in the starburst ring (13CO J = 1-0 and C18O J = 1-0).