Centrality dependence of charged particle multiplicity at midrapidity in Au+Au collisions at<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:msqrt><mml:mrow><mml:mrow><mml:msub><mml:mrow><mml:mi>s</mml:mi></mml:mrow><mml:mrow><mml:mi>NN</mml:mi></mml:mrow></mml:msub></mml:mrow></mml:mrow></mml:msqrt><mml:mo>=</mml:mo><mml:mn>130</mml:mn><mml:mn/><mml:mi> </mml:mi><mml:mi mathvariant="normal">GeV</mml:mi></mml:math>

We present a measurement of the pseudorapidity density of primary charged particles near midrapidity in Au+Au collisions at $\sqrt{{s}_{\mathrm{NN}}}=130 \mathrm{GeV}$ as a function of the number of participating nucleons. The pseudorapidity density, ${\mathrm{dN}}_{\mathrm{ch}}/d\ensuremath{\eta}{|}_{|\ensuremath{\eta}|&lt;1}/(\frac{1}{2}〈{N}_{\mathrm{part}}〉),$ rises from $2.87\ifmmode\pm\else\textpm\fi{}0.21$ in peripheral events $(〈{N}_{\mathrm{part}}〉\ensuremath{\sim}83)$ to $3.45\ifmmode\pm\else\textpm\fi{}0.18$ in central events $(〈{N}_{\mathrm{part}}〉\ensuremath{\sim}353),$ which is $53\ifmmode\pm\else\textpm\fi{}8%$ higher than $p\overline{p}$ collisions at a similar center-of-mass energy. This is consistent with an additional contribution to charged particle production that scales with the number of binary nucleon-nucleon collisions ${(N}_{\mathrm{coll}}).$