Radio observations

Stewart Eyres, Astrophysics Research Institute, Liverpool John Moores University, Twelve Quays House, Egerton Wharf, Birkenhead, CH41 1LD, UK

I present the results of observations with the JCMT, ATCA, MERLIN and the VLA. JCMT searches for CO have been negative to date, providing upper limits on the molecular content of the planetary nebula associated with V4334 Sgr. MERLIN observations hoping to detect emission from the wind have so far proven negative. Observations with ATCA at several wavelengths give upper limits of about 2mJy. The VLA has successfully imaged the planetary nebula, and it is found to coincide with that seen in the optical; the angular radius is about 17''. Fitting of Gaussian components indicates the presence of around 60 discrete knots, and that the total flux density is 2.7mJy. Comparison with estimates of the total H$\beta$ flux indicates a reddening consistent with $E(B-V) = 0.88\pm0.03$, although uncertainties in this are dominated by the H$\beta$ flux estimate. This is consistent with a distance of around 2kpc; the ionised mass is estimated from the radio emission measure to be about 0.03M$_\odot$.