J/A+A/320/776 J/A+A/320/776 Tidal radii of 7 globular clusters I Lehmann R -D Scholz Astron. Astrophys. 320 776 1997 1997A&A...320..776L Clusters, globular globular clusters: general methods: statistical We present new tidal radii for seven Galactic globular clusters using the method of automated star counts on Schmidt plates of the Tautenburg, Palomar and UK telescopes. The plates were fully scanned with the APM system in Cambridge (UK). Special account was given to a reliable background subtraction and the correction of crowding effects in the central cluster region. For the latter we used a new kind of crowding correction based on a statistical approach to the distribution of stellar images and the luminosity function of the cluster stars in the uncrowded area. The star counts were correlated with surface brightness profiles of different authors to obtain complete projected density profiles of the globular clusters. Fitting an empirical density law (King 1962AJ.....67..471K) we derived the following structural parameters: tidal radius rt, core radius rc and concentration parameter c. In the cases of NGC 5466, M 5, M 12, M 13 and M 15 we found an indication for a tidal tail around these objects (cf. Grillmair et al., 1995AJ....109.2553G).

M 5NGC 5904C 1516+02215 18 33.7+02 04 58 M 12NGC 6218C 1644-01816 47 14.4-01 56 52 M 13NGC 6205C 1639+36516 41 41.4+36 27 37 M 15NGC 7078C 2127+11921 29 58.3+12 10 00 M 53NGC 5024C 1310+18413 12 55.1+18 12 09 NGC 5053C 1313+17913 16 26.9+17 41 52 NGC 5466C 1403+28714 05 27.3+28 32 04

Name Galaxy name --- Rad Mean radius of an annulus arcmin Dens Background and crowding corrected stellar density in number per arcmin^2^ ct/arcmin2 e_Dens uncertainty in Dens (number per arcmin^2^) ct/arcmin2 Patricia Bauer CDS 1998Feb23Ingo Lehmann <ilehmann@aip.de> J_A+A_320_776.xml