Untriggered di-hadron correlations in Pb-Pb collisions at $\sqrt{s_{NN}}=$ 2.76 TeV from ALICE

We present measurements of untriggered di-hadron correlations as a function of centrality in Pb-Pb \sNN collisions, for charged hadrons with $p_T>0.15$ GeV$\mathrm{/}c$. These measurements provide a map of the bulk correlation structures in heavy-ion collisions. Contributions to these structures may come from jets, initial density fluctuations, elliptic flow, resonances, and/or momentum conservation. We decompose the measured correlation functions via a multi-parameter fit in order to extract the nearside Gaussian, the longer range $\mathrm{\Delta }\eta$ correlation often referred to as the soft ridge. The effect of including higher harmonics ($v_3$ and $v_4$) in this procedure will be discussed. We investigate how the nearside Gaussian scales with the number of binary collisions. Finally, we show the charge dependence of the nearside Gaussian.