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Detection of radio pulsar pairs -
possible components of broken binary systems

Russian version

    According to modern views on the evolution and origin of stars, most of the stars are members of binary systems. If both components are massive enough, they eventually go supernova one by one, whereas their cores collapse, turning into black holes or neutron stars. After the second explosion, the pairs tend to break up and neutron stars and/or black holes fly apart. High velocities of radio pulsars are apparently largely due to this effect. Thus, the kinematic characteristics of a pulsar (its position in the alaxy, peculiar velocities) in combination with age carry the data about its location at the time of birth. Comparing these parameters in different pairs of sufficiently close objects, we can find among them the companions that were part of broken binary systems. To this end, we developed a method of analysis of the kinematics of single radio pulsars, which have their proper motions and distances measured. Using a standard distribution of radial velocities for each object, we have computed from 100 to 300 thousand trajectories of its hypothetical movement in the gravitational field of the Galaxy on the scale of a few million years. For all possible pairs the probability of trajectory approach at small distances for the epoch, corresponding to the age of the younger pulsar have been evaluated. In the case when these probabilities significantly exceed the reference values, obtained in an assumption of a purely random approach of the studied objects, it can be argued that they were part of a single binary system. As a result, six pairs of pulsars were fond: J0543+2329/J0528+2200, J1453-6413/J1430-6623, J2354+6155/J2321+6024, J1915+1009/J1909+1102, J1832-0827/J1836-1008, J1917+1353/J1926+1648, which were the companions in broken up binary systems with a high probability.
G.Beskin, L.Chmyreva, A.Biryukov

Contact - G.Beskin

Fig.1. Pulsars J0543+2329 and J0528+2200. The projections of the spatial plane, where the measured minimal distance between the pulsars does not exceed ρ=10pc. Every dot on the diagram is a place of the the closest approach of pulsars for a given pair of trajectories. The circles mark the location of a younger pulsar at the current epoch, the diamonds - the location of an older pulsar. The lines are the trajectories at which the smallest computed distance between the pulsars ρmin is realized. The stars mark the region of its reach. Here ρmin=0.535pc.