Water Masers in Nearby Galaxies

Water masers in a galaxy provide proxies for identifying star forming regions and are therefore of particular interest. 

22 GHz water masers were found in four nearby galaxies. The locations of these water masers coincides with ultradense H-II regions. These regions correspond also to bright 24 pm emission areas (see Darling, Brogan and Johnson, 2009 [93] and 2008 [92]). 

Using the Expanded Very Large Array, Edmonds et al., 2008 [113] have conducted a search for 22.2 GHz H2O megamaser emission in the strongly lensed sub mm galaxy, SMM J16359 -I- 6612 at z = 2.517. They did not detect any water maser emission but were able to set an upper limit on the luminosity of any water maser present (LH20 5305 L ). 

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