  We present measurements of the pseudorapidity distribution of primary charged
particles produced in Au+Au collisions at three energies, sqrt(s_{NN}) = 19.6,
130, and 200 GeV, for a range of collision centralities. The centrality
dependence is shown to be non-trivial: the distribution narrows for more
central collisions and excess particles are produced at high pseudorapidity in
peripheral collisions. For a given centrality, however, the distributions are
found to scale with energy according to the "limiting fragmentation"
hypothesis. The universal fragmentation region described by this scaling grows
in pseudorapidity with increasing collision energy, extending well away from
the beam rapidity and covering more than half of the pseudorapidity range over
which particles are produced. This approach to a universal limiting curve
appears to be a dominant feature of the pseudorapidity distribution and
therefore of the total particle production in these collisions.
