Baha

We present first results of a long term study: Searching for OB–type runaway stars inside supernova remnants (SNRs). We identified spectral types and measured radial velocities (RV) by optical spectroscopic observations and we found OB runaway stars inside SNR S147 and IC443. HD 37424 is a B0.5V type star with a peculiar velocity of 74.0$pm$8 $mathrm{km,s^{-1}}$. Tracing back the past trajectories via Monte Carlo simulations, we found that HD 37424 was located at the same position as the central source PSR J0538$mathrm{+}$2817 30$pm$4 kyr ago. This position is only $sim$4 arcmin away from the geometrical center of the SNR. So, we suggest that HD 37424 was the pre–supernova binary companion to the progenitor of the pulsar and the SNR. We found a distance of 1333$^{+103}_{-112}$ pc to the SNR. The age is 30$pm$4 kyr and the total visual extinction towards the center is 1.28$pm$0.06 mag. The zero age main sequence progenitor mass should be greater than 13 M$_{odot}$. We calculated the pre–supernova binary parameters for different progenitor masses. The values found for the Roche Lobe radii suggest that it was an interacting binary in the late stages of the progenitor. This is the first OB runaway star ever found which is directly linked to a neutron star (NS) and a SNR. Another OB runaway star we found is the B0II/III type star HD 254577 inside SNR IC443. The proper motion of the star is significantly larger than the average proper motion of the other members of GEM OB1 association. The peculiar velocity of the star is $35pm7$ km$^{-1}$s at 1.5 kpc. The bow shock direction of the pulsar wind nebula shows that the NS and HD 254577 may have a common origin; binary supernova disruption. Unlike S147, the explosion center we found is far away from the geometrical center, close to the eastern edge of the remnant. But the relation to the SNR is still possible. This source provided us with important information of SNR expansion in the medium with inhomogeneous density distribution.