We study general properties of attractors for tachyonic potential chameleon scalar-field model which possess cosmological scaling solutions. An analytic formulation is given to obtain fixed points with a discussion on their stability. The model predicts a dynamical equation of state parameter with phantom crossing behavior for an accelerating universe. We constrain the parameters of the model by best fitting with the recent data-sets from supernovae and simulated data points for redshift drift experiment generated by Monte Carlo simulations.

We study the general properties of attractors in a cosmological model with tachyonic potential and a scalar field nonminimally coupled to matter. In the conventional approach to the stability analysis the qualitative properties of the equations and of the long-term behavior of the solutions are investigated where the scaling solutions are the late time attractors and independent of the initial conditions. In this article, in a new approach, we examine the stability analysis of the model by simultaneously solving the dynamical system and best fitting the stability parameters with the observational data. The advantage of this approach is that the model which was of a purely mathematical nature become physically motivated. The number of the new critical points and also their properties, given in terms of the best-fitted parameters, may alter due to the best-fitting procedure. In a further step in stability analysis, we best fit both the stability parameters and initial conditions with the observational data. The results impose more constraints on the trajectories in the phase space and provide more information about the dynamics of the cosmological model.