High Transverse Momentum Triggered Correlations over a Large Pseudorapidity Acceptance in<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mi>Au</mml:mi><mml:mo>+</mml:mo><mml:mi>Au</mml:mi></mml:math>Collisions at<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:msqrt><mml:msub><mml:mi>s</mml:mi><mml:mrow><mml:mi>N</mml:mi><mml:mi>N</mml:mi></mml:mrow></mml:msub></mml:msqrt><mml:mo>=</mml:mo><mml:mn>200</mml:mn><mml:mtext> </mml:mtext><mml:mtext> </mml:mtext><mml:mi>GeV</mml:mi></mml:math>

A measurement of two-particle correlations with a high transverse momentum trigger particle (${p}_{T}^{\mathrm{trig}}&gt;2.5\text{ }\text{ }\mathrm{GeV}/c$) is presented for $\mathrm{Au}+\mathrm{Au}$ collisions at $\sqrt{{s}_{NN}}=200\text{ }\text{ }\mathrm{GeV}$ over the uniquely broad longitudinal acceptance of the PHOBOS detector ($\ensuremath{-}4&lt;\ensuremath{\Delta}\ensuremath{\eta}&lt;2$). A broadening of the away-side azimuthal correlation compared to elementary collisions is observed at all $\ensuremath{\Delta}\ensuremath{\eta}$. As in $p+p$ collisions, the near side is characterized by a peak of correlated partners at small angle relative to the trigger particle. However, in central $\mathrm{Au}+\mathrm{Au}$ collisions an additional correlation extended in $\ensuremath{\Delta}\ensuremath{\eta}$ and known as the ``ridge'' is found to reach at least $|\ensuremath{\Delta}\ensuremath{\eta}|\ensuremath{\approx}4$. The ridge yield is largely independent of $\ensuremath{\Delta}\ensuremath{\eta}$ over the measured range, and it decreases towards more peripheral collisions. For the chosen ${p}_{T}^{\mathrm{trig}}$ cut, the ridge yield is consistent with zero for events with less than roughly 100 participating nucleons.

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