5. Observations and results
Two clusters, M 3 and M 22, were observed, at 800 µm and 1100 µm respectively. These clusters were chosen on the basis of their closeness and high mass. The salient properties of the clusters are given in Tables 1 and 3.
Table 1. Properties of M 3 and M 22. The sources of the figures are: Radii information - from Trager et al. (1995); Mass - from Pryor & Meylan (1993); [Fe/H] - from Kraft et al. (1995; M 3), Brown & Wallerstein (1992; M 22); D, distance from the Sun - Paez (1990) and Peterson & Cudworth (1994)
Table 2. Upper limits on millimetre fluxes
Table 3. Orbital properties of M 3 and M 22. The sources of the figures are: U, V, W, x, y, z, present space velocities and positions, in a right-handed Galactocentric Cartesian coordinate system with z pointing to the Galactic North Pole and x opposite to the Sun - from Scholz, Odenkirchen & Irwin (1993) and Cudworth & Hanson (1993)
The observations were carried out using the He3 -cooled UKT14 bolometer on the James Clerk Maxwell Telescope (JCMT) on 1995 March 7th. Mars was used for flux calibration and pointing sources in the observatory catalogue were used to check pointing and focussing; pointing was accurate to . Observations were made on GC centres, the positions of which were taken from Shawl & White (1986). The observations generally consisted of several sets of 50 20-sec cycles for M 3, and 20 50-sec cycles for M 22; the total on-source time was 2485 sec for M 3 and 4000 sec for M 22. The chop throw was at 4 Hz, with a beamsize as specified in Table 2. Neither cluster was detected, to the limits given in Table 2.
© European Southern Observatory (ESO) 1997
Online publication: July 8, 1998