DEEP RADIO OBSERVATION OF THE RICH GLOBULAR-CLUSTERS TERZAN-5 AND LILLER-1

We have obtained deep 6, 20 and 90 cm observation of two of the riches t globular clusters in the galaxy Terzan 5 and Liller 1. In addition t o the well known eclipsing pulsar, PSR1744-24A, our 20 cm image of Ter zan 5 displays numerous point sources within 30 '', or 4 core radii of the cluster center. The density of these objects rises rapidly toward the core, where an elongated region of emission is found. This featur e may be due to the presence of a higher density of point sources than can be resolved by the 1 '' resolution of our data. Observations at 6 and 90 cm show that the brightest individual sources, as well as the extended emission, possess the steep spectra expected of pulsars. Furt hermore, we find that the strength of the sources in the 20 cm image a grees well with the standard pulsar luminosity function. The total lum inosity and number of objects observed in Terzan 5 suggest that this c luster may contain 100 pulsars - probably more than any other Galactic cluster. Although we do not resolve individual sources in Liller 1, c omparison of our images with other observations suggests that we are a gain observing the sum of emission from a number of objects. The 90 cm flux densities of Terzan 5 and Liller 1 are 35 and 9 mJy, respectivel y, implying that a number of bright pulsars in these clusters have bee n hidden from pulsed searches, perhaps by a combination of dispersion smearing, scattering and doppler broadening.