The local star formation history of the thin disc derived from kinematic data - AstrophysicsReport as inadecuate




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Abstract: We present an evolutionary disc model for the thin disc in the solar cylinderbased on a continuous star formation history and a continuous dynamical heatingof the stellar subpopulations. The vertical distribution of the stellarsubpopulations are calculated self-consistently in dynamical equilibrium. TheSFR and AVR of the stellar subpopulations are determined by fitting thevelocity distribution functions of main sequence stars. The SFR shows a maximum10 Gyr ago declining by a factor of 10 until present time. A constant SFR canbe ruled out. The velocity dispersion of the stellar subpopulations increasewith age according to a power law with index 0.375. The new scale heights leadto a best fit IMF with power-law indices of 1.5 below and 4.0 above 1.6 Msun,which has no kink around 1 Msun. Including a thick disc component results inslight variations of the thin disc properties, but has a negligible influenceon the SFR. A variety of predictions are made concerning the number density,age and metallicity distributions of stellar subpopulations as a function of zabove the galactic plane.



Author: A. Just, H. Jahreiss

Source: https://arxiv.org/







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