A Pulsar Orbiting the Galactic Center
Bower et al. used the VLBA to determine the proper motion of pulsar J1745-2900 relative to the Galactic Center. The pulsar has a transverse velocity of 236 ± 11 km/s at a projected separation of 0.097 parsecs from Sgr A*. The angular broadening with frequency is similar to Sgr A*. The velocity and position is consistent with a bound orbit originating in the clockwise disk of massive stars orbiting Sgr A* and a natal velocity kick of < 500 km/s. These results for PSR J1745-2900 support the hypothesis that Galactic Center pulsars can originate in the inner stellar disk, and deepens the mystery regarding the small number of detected Galactic Center pulsars to date.
Image: Position as a function of time for PSR J1745-2900 relative to Sgr A*
Science Team: Geoffrey C. Bower (ASIAA), Adam Deller (ASTRON), Paul Demorest (NRAO), Andreas Brunthaler (Max-Planck Institut für Radioastronomie), Heino Falcke (ASTRON, Max-Planck Institut für Radioastronomie, Radboud University), Monike Moscibrodzka (Radboud University), Ryan M. O’Leary (JILA), Ralph P. Eatough (Max-Planck Institut für Radioastronomie), Michael Kramer (Max-Planck Institut für Astronomie, Jodrell Bank), K.J. Lee (Max-Planck Institut für Radiostronomie), Laura Spitler (Max-Planck Institut für Radiostronomie), Gregory Desvignes (Max-Planck Institut für Radiostronomie), Anthony P. Rushton (University of Oxford, University of Southampton), Sheperd Doeleman (MIT Haystack Observatory, Harvard-Smithsonian Center for Astrophysics), and Mark J. Reid (Harvard-Smithsonian Center for Astrophysics).
Publication: The Proper Motion of the Galactic Center Pulsar Relative to Sagittarius A*, 2015, Astrophysical Journal, 798, 120.