Based upon ortho-H₂O, HO, and O (1₁₀ − 1₀₁) observations;

this paper;

from Herschel mapping of the CND/Sgr A* by Armijos-Abendano et al. (2019);

from Herschel mapping of the +20 km s⁻¹ Cloud by Armijos-Abendano et al. (2019);

from Karlsson et al. (2013), assuming an ortho-to-para ratio of 3;

outflow/shock;

circumnuclear Disk (torus) surrounding the Sgr A* black hole;

foreground spiral arm;

Olofsson et al. (2003);

Wirström et al. (2006);

Odin spectral scan, Persson et al. (2007);

Herschel/HIFI spectral scan, Neill et al. (2013);

Melnick et al. (2010);

mapped in detail by Odin, Hjalmarson et al. (2005);

based upon para-H₂O (1₁₁ − 0₀₀) observations, van der Tak et al. (2010);

assuming an ortho-to-para ratio of 3;

from Odin mapping by Wilson et al. (2003) in close agreement with SWAS results by Snell et al. (2000);

clump/interclump values;

from Odin mapping by Persson et al. (2009).

the lower abundance estimates appear at higher densities and can be accommodated by PDR models, while the high abundances (at a density of 10⁴ cm⁻³) would indicate that the existing shocks also contribute to the observed ground state H₂O emission.

shock model abundance (Flower & Pineau des Forêts 2010) in an effective (accumulated) 10″ size area of the circumnuclear torus (see Sect. 4.4).

caused by slow velocity shock chemistry in the case of (here unconfirmed) dominant FIR excitation (González-Alfonso et al. 2010, 2012, 2014).