The PHENIX experiment at RHIC measured single electron spectra in p + p, d + Au and Au + Au collisions at \documentclass[12pt]{minimal}
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\begin{document}$\sqrt{s_{NN}} = 200$\end{document} GeV, and in Au + Au collisions at \documentclass[12pt]{minimal}
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\begin{document}$\sqrt{s_{NN}} = 62.4$\end{document} GeV. In these spectra, electrons from semi-leptonic decays of charmed particles are the dominant contribution after subtraction of all 'photonic' sources (photon conversions, Dalitz decays, decays of light vector mesons). The p + p open charm production cross-section is found to be in good agreement with pQCD NLO calculations. The shape of the distributions obtained for p + p interactions is compared with those observed for nucleus-nucleus collisions. From p + p to d + Au and Au + Au interactions, open charm production is found to scale with the number of binary collisions \documentclass[12pt]{minimal}
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\begin{document}$N_{\rm coll}$\end{document}. Au + Au data at \documentclass[12pt]{minimal}
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\begin{document}$\sqrt{s_{NN}} = 62.4$\end{document} GeV is compatible with the ISR p + p results scaled by \documentclass[12pt]{minimal}
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\begin{document}$N_{\rm coll}$\end{document}. The elliptic flow parameter v2 of heavy flavor electrons has also been measured, and is found to be non-zero in the intermediate pT range.
