Combined constraints on modified Chaplygin gas model from cosmological observed data: Markov Chain Monte Carlo approach

We use the Markov Chain Monte Carlo method to investigate a global constraints on the modified Chaplygin gas (MCG) model as the unification of dark matter and dark energy from the latest observational data: the Union2 dataset of type supernovae Ia (SNIa), the observational Hubble data (OHD), the cluster X-ray gas mass fraction, the baryon acoustic oscillation (BAO), and the cosmic microwave background (CMB) data. In a flat universe, the constraint results for MCG model are, Omega(b)h(2) = 0.02263(-0.00162)(+0.00184) (1 sigma)(-0.00195)(+0.00213)(2 sigma), B-s = 0.7788(-0.0723)(+0.0736)(1 sigma)(-0.0904)(+0.0918)(2 sigma), alpha = 0.01079(-0.2539)(+0.3397)(1 sigma)(-0.2911)(+0.678)(2 sigma), B = 0.00189(-0.00756)(+0.00583)(1 sigma)(-0.00915)(+0.00660)(2 sigma), and H-0 = 70.711(-3.142)(+4.188)(1 sigma)(-4.149)(+5.281)(2 sigma).