ner_tags: O O O O O O O O O O O O B-Telescope O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B-Citation I-Citation I-Citation I-Citation O O O O B-Citation I-Citation O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B-Model O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B-Telescope O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O
tokens: The noise is slightly lower (about 15%) than expected from the online APEX calculator because our noise measurements are made in moderately smoothed maps. 2.3. Baselining The data showed significant baseline structure, leading to large-scale correlated components in the resulting spectra. The baselines were removed over a velocity range km s -1 by the following procedure: 1. identify bright PPV regions in the line using the technique described in Sect. 3 ; 2. mask the regions identified as -bright for each other spectral line data cube; 3. fit a polynomial to the un-masked data; 4. subtract the fitted polynomial. We used a 7th-order polynomial for this process because lower order baseline removal left a significant and patterned residual. A more detailed examination of the baseline removal process is described in Appendix A . 3. Signal extraction and masking We use the method described partially in Ao et al. (2013) and more thoroughly in Dame (2011) to mask the data cubes at locations of significant signal in the brightest line. A noise map was created by computing the sample standard deviation over a 200 km s -1 range in which no signal was present. We use the line, which is the brightest of the lines, to create the mask by the following procedure: 1. Smooth the data with a Gaussian of width two pixels in each direction (spatial, , and spectral, km s -1 ). 2. Create an inclusive mask of all pixels with brightness in the smoothed map. 3. Grow the mask from the previous step by one pixel in each direction (this is known in image processing as binary dilation). The mask was then applied to the and cubes created with the same PPV gridding. There is some overlap between the line and the line in PPV space, so we shifted the mask to the velocity of the line in the cube and excluded those pixels expected to contain emission. However, inspection of the cube revealed that significant chunks of the signal were excised by this masking, so all further analysis excludes the line. Integrated intensity maps are shown in Fig. 2 a for the map masked with the above method and in Fig. 2 b for the map using the mask created from the data. Fig. 2 Integrated intensity (moment 0) maps of the a) and b) lines. The cubes were masked prior to integration using the method described in Sect. 3 . Selected region names are labeled. The thin black contours are at a column from the Herschel SED fit maps. 3.1. Ratio maps We have created ratio maps as a first step toward building temperature maps. In general, a higher indicates a higher temperature, and therefore the ratio maps are a good proxy for relative temperature. We display four different varieties of ratio map in Figs. 3 and E.1 . Figure 3 shows maps produced by creating ratio cubes, in which each voxel has the value , then averaging across velocity with constant weight for each voxel in Fig. 3 a and with the weight set by the brightness value in Fig. 3 b. In both cases, the mask described in Sect. 3 was applied to the