Reconstructing the properties of dark energy from recent observations

We explore the properties of dark energy from recent observational data, including the Gold Sne Ia, the baryonic acoustic oscillation peak from SDSS, the CMB shift parameter from WMAP3, the x-ray gas mass fraction in clusters and the Hubble parameter versus redshift. The Lambda CDM model with curvature and two parameterized dark energy models are studied. For the Lambda CDM model, we find that the. at universe is consistent with observations at the 1 sigma confidence level and a closed universe is slightly favored by these data. For two parameterized dark energy models, with the prior given on the present matter density, Omega(m0), with Omega(m0) = 0.24, Omega(m0) = 0.28 and Omega(m0) = 0.32, our result seems to suggest that the trend of Omega(m0) dependence for an evolving dark energy from a combination of the observational datasets is model-dependent.