F. Palagi

Long-term study of water maser emission associated with young stellar objects - I. The database

We present the results of more than 10 years of monitoring of the water vapor maser emission in 14 star forming regions obtained with the Medicina 32-m radiotelescope. The sample of objects covers a large range of luminosities of the associated FIR sources. In order to present in a compact and representative way the large amount of data available, we give for each source: a time-velocity-flux density plot, the time dependent integrated flux, the lower and upper envelopes of the maser emission, the frequency of the maser occurrence as a function of velocity, and the mean velocity averaged over the observing period. A brief morphological description of the environment of the maser source is also given. The present data form the basis for a discussion of the main properties of the water vapor maser emission to be presented in a forthcoming paper.

Molecular outflows and H2O masers: What type of connection?

From the search of water maser emission in a sample of 142 molecular outflow sources, we find a relationship between the integrated water maser luminosity and the mechanical luminosity of the outflow (Felli et al. 1992). This relationship is also expected by the model of masers excited by shocks produced by stellar winds.

10.7 GHz continuum observations of comet P/Halley

A search for continuum emission at 10.7 GHz from Halley’s comet has been performed with the Bologna 32 m radio-telescope near the first comet perigee. Owing to the expected low fluxes the beam switching ON-OFF technique was adopted for the observations. Sky background level was determined by subtraction of instrumental and sky temperature long term drifts using a least square fit method. Long time integrations (> 3000 s) were obtained for 7 days. The results indicate 2 detections greater than 3σ level with fluxes of ~ 14 mJy.