6 Summary

We have given the results of a survey of the region $5^{\circ} \le \ell \le 45^{\circ}$ and $\vert b\vert \le 3^{\circ}$ in the OH 1612.231 MHz maser line. The survey is 99% complete for sources brighter than 500 mJy and 90% complete for positional offsets from the pointing centres smaller than 13$^\prime$. The absolute flux density limit is $\sim$120 mJy. We have found 286 compact OH-maser sources, 161 of which are new detections. The sources are mainly OH/IR stars, with a few related sources, like planetary nebulae. The positions are accurate to 2 $^{\prime \prime }$, the velocities to 1kms^-1 and the flux densities to 20%. For 207 sources, an associated IRAS point source is found. The total number of sources in the combined ATCA/VLA survey is 766.

The VLA survey is similar to the ATCA surveys in terms of global completeness statistics, but considerably less homogeneous in quality. The efficiency is approximately 75% that of the ATCA Bulge survey. The biggest differences are the considerably worse accuracy in the flux densities and the very low fraction of single-peaked sources. Signatures of a higher fraction of bar-like stars in this part of the survey than in the ATCA Disk survey are found in the surface number density of detected sources and arguably in the IRAS two-colour diagram.

Acknowledgements

This research has made use of the Simbad database, operated at CDS, Strasbourg, France.