MODELING THE DISTRIBUTION OF MAGNETIC FLUXES IN-FIELD CONCENTRATIONS IN A SOLAR ACTIVE-REGION

Much of the magnetic field in solar and stellar photospheres is arrang ed into clusters of 'flux tubes', i.e., clustered into compact areas i n which the intrinsic field strength is approximately a kilogauss. The flux concentrations are constantly evolving as they merge with or ann ihilate against other concentrations, or fragment into smaller concent rations. These processes result in the formation of concentrations con taining widely different fluxes. Schrijver et al. (1997, Paper I) deve loped a statistical model for this distribution of fluxes, and tested it on data for the quiet Sun. In this paper we apply that model to a m agnetic plage with an average absolute flux density that is 25 times h igher than that of the quiet network studied in Paper I. The model res ult matches the observed distribution for the plage region quite accur ately. The model parameter that determines the functional form of the distribution is the ratio of the fragmentation and collision parameter s. We conclude that this ratio is the same in the magnetic plage and i n quiet network. We discuss the implications of this for (near-)surfac e convection, and the applicability of the model to stars other than t he Sun and as input to the study of coronal heating.