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Indexed by:期刊论文

Date of Publication:2011-03-01

Journal:ASTRONOMY & ASTROPHYSICS

Included Journals:SCIE

Volume:527

ISSN No.:1432-0746

Key Words:cosmological parameters; gamma rays: galaxies

Abstract:Aims. We investigate observational constraints on the generalized Chaplygin gas (GCG) model including the gamma-ray bursts (GRBs) at high redshift obtained directly from the Union2 type Ia supernovae (SNe Ia) set.
   Methods. By using the Markov Chain Monte Carlo method, we constrain the GCG model with the cosmology-independent GRBs, as well as the Union2 set, the cosmic microwave background (CMB) observation from the Wilkinson Microwave Anisotropy Probe (WMAP7) result, and the baryonic acoustic oscillation (BAO) observation from the spectroscopic Sloan Digital Sky Survey (SDSS) data release 7 (DR7) galaxy sample.
   Results. The best-fit values of the GCG model parameters are A(S) = 0.7475(-0.0539)(+0.0556)(1 sigma)(-0.0816)(+0.0794) (2s), alpha = -0.0256(-0.1326)(+0.1760)(1 sigma)(-0.1907)(+0.2730)(2 sigma), and the effective matter density Omega(m) = 0.2629(-0.0153)(+0.0155)(1s)(-0.0223+0.0236)(2 sigma), which are more stringent than previous results for constraining GCG model parameters.