SIMBAD references

We present observations of the Type Ia supernovae (SNe) 1999M, 1999N, 1999Q, 1999S, and 1999U, at redshift z~0.5. They were discovered in early 1999 with the 4.0 m Blanco telescope at Cerro Tololo Inter-American Observatory by the High-z Supernova Search Team (HZT) and subsequently followed with many ground-based telescopes. SNe 1999Q and 1999U were also observed with the Hubble Space Telescope. We computed luminosity distances to the new SNe using two methods and added them to the high-z Hubble diagram that the HZT has been constructing since 1995. The new distance moduli confirm the results of previous work. At z~0.5, luminosity distances are larger than those expected for an empty universe, implying that a ``cosmological constant'', or another form of ``dark energy'', has been increasing the expansion rate of the universe during the last few billion years. Combining these new HZT SNe Ia with our previous results and assuming a ΛCDM cosmology, we estimate the cosmological parameters that best fit our measurements. For a sample of 75 low-redshift and 47 high-redshift SNe Ia with MLCS2k2 (Jha and coworkers) luminosity calibration we obtain Ω_M=0.79^+0.15_–0.18 and Ω_Λ=1.57^+0.24_–0.32(1 σ uncertainties) if no constraints are imposed, or Ω_M=0.29^+0.06_–0.05if Ω_M+Ω_Λ=1 is assumed. For a different sample of 58 low-redshift and 48 high-redshift SNe Ia with luminosity calibrations done using the PRES method (a generalization of the Δm₁₅method), the results are Ω_M=0.43^+0.17_–0.19 and Ω_Λ=1.18^+0.27_–0.28(1 σ uncertainties) if no constraints are imposed, or Ω_M=0.18^+0.05_–0.04if Ω_M+Ω_Λ=1 is assumed.