The Effects of Starburst Activity on Low Surface Brightness Disk Galaxies

Although numerous simulations have been done to understand the effects ofintense bursts of star formation on high surface brightness galaxies, fewattempts have been made to understand how localized starbursts would affectboth the color and surface brightness of low surface brightness (LSB) galaxies.To remedy this, we have run 53 simulations involving bursts of star formationactivity on LSB galaxies, varying both the underlying galaxy properties and theparameters describing the starbursts. We discovered that although changing thetotal color of a galaxy was fairly straightforward, it was virtually impossibleto alter a galaxy's central surface brightness and thereby remove it from theLSB galaxy classification without placing a high (and fairly artificial)threshold for the underlying gas density. The primary effect of large amountsof induced star formation was to produce a centralized core (bulge) componentwhich is generally not observed in LSB galaxies. The noisy morphologicalappearance of LSB galaxies as well as their noisy surface brightness profilescan be reproduced by considering small bursts of star formation that arelocalized within the disk. The trigger mechanism for such bursts is likelydistant/weak tidal encounters. The stability of disk central surface brightnessto these periods of star formation argues that the large space density of LSBgalaxies at z = 0 should hold to substantially higher redshifts.