We present preliminary results from OH ground state phase referenced observations carried out with the Multi Element Radio Linked Interferometer Network (MERLIN) and e-MERLIN towards the massive star forming region W49A. There are three active SFRs within this complex: W49 North (W49 N), W49 South (W49 S) and W49 South West (W49 SW). The first epoch of observations was obtained in 2005 with MERLIN while the second epoch was obtained in 2013 with the e-MERLIN upgraded system. In this paper, we present 1665 and 1720 MHz maser emission towards W49 S and W49 SW. Overall, both epochs show good agreement with the previous observations of Argon et al. (2000) carried out with the Very Large Array (VLA). The better sensitivity and wider velocity coverage of the MERLIN/e-MERLIN observations allowed us to discover a new 1720 MHz OH maser site in W49 S.

ABSTRACT
1. INTRODUCTION
2. OBSERVATIONS AND RESULTS
3. CONCLUSIONS AND FUTURE WORK
REFERENCES

• Kitiyanee Asanok(Department of Physics, Faculty of Science, Khon Kaen University)
• Sandra Etoka(Hamburger Sternwarte)
• Malcolm D. Gray(The University of Manchester, Jodrell Bank Centre for Astrophysics, School of Physics and Astronomy, Alan Turing Building)
• Anita M. S. Richards(The University of Manchester, Jodrell Bank Centre for Astrophysics, School of Physics and Astronomy, Alan Turing Building)
• Busaba H. Kramer(Max-Planck-Institut fur Radioastronomie/National Astronomical Research Institute of Thailand, Ministry of Science and Technology)
• Nipon Gasiprong(Department of Physics, Faculty of Science, Ubon Ratchathani University)