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Paper: The Local Star Formation History of the Disk
Volume: 275, Disks of Galaxies: Kinematics, Dynamics and Perturbations
Page: 117
Authors: Just, A.
Abstract: The local age distribution of main sequence stars changes dramatically with stellar mass for stars with a lifetime shorter than the age of the galactic disk (i.e. above ≈ 0.9 Modot). Dynamical heating of the disk leads to an increasing vertical scale height of stellar populations with increasing age. This results in an enhanced relative contribution of young stars in the solar neighbourhood and a systematic variation of the velocity distribution function along the main sequence. Additionally the difference between the present day mass function (PDMF) and the initial mass function (IMF) depends strongly on the long term star formation history (SFR(t)). Both effects can be efficiently used to determine the SFR from the PDMF and kinematical data. We use a self-consistent disk model in order to derive the SFR from the observed PDMF and the local velocity distribution functions of the stars. We find, that the SFR shows a strong maximum in the first 2 Gyr and a moderate decline in the second half of the disks life at a relatively low level.
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