In order to specify cosmologically motivated initial conditions for major galaxy mergers (mass ratios 6 4:1) that are supposed to explain the formation of elliptical galaxies we study the orbital parameters of major mergers of cold dark matter halos using a high-resolution cosmological simulation. Almost all encounters are nearly parabolic with eccentricities e ≈ 1 and no correlations between t...

We introduce EXOFIT, a Bayesian tool for estimating orbital parameters of extra-solar planets from radial velocity measurements. EXOFIT can search for either one or two planets at present. EXOFIT employs Markov Chain Monte Carlo method implemented in an object oriented manner. As an example we re-analyze the orbital solution of HD155358 and the results are compared with that of the published or...

We present a simple novel method for determining the orbital parameters of binary pulsars. This method works with any sort of orbital sampling, no matter how sparse, provided that information on the period derivatives is available with each measurement of the rotational period of the pulsar, and it is applicable to binary systems with nearly circular orbits. We use the technique to precisely es...