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| EPoS Contribution |
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Periodic masers in G9.62+0.20E: Seeing the Unseen
Johan van der Walt Unit for Space Physics, North-West University, Potchefstroom, South Africa | |
| The first class II masers that were found to show periodic flaring was in the star forming region G9.62+0.20E. I will present further data to show that the flaring occurs not only at 6.7 and 12.2 GHz but that the 107 GHz masers also flares. Analysis of the data shows that the flare profiles in each of the three transitions are similar, thereby putting constraints on the origin of the variability. I will argue that the flaring is most likely due to variability in the background hypercompact Hii region. I will also show that the observed flare profile can be explained in a very simple and natural way in terms of the properties of Hii regions. The conclusion is that the periodicity of the flaring may be due to flaring activity directly associated with the young star as such or being due to the effect of a binary companion star that triggers mass transfer to the massive star leading to a flaring event that in turn affects the Hii region. The case of G9.62+0.20E may be the only example at the moment where with the aid of maser emission we are seeing what is otherwise unseen to due to the very high optical depths at which massive stars form. | |