Kinematics of black hole x-ray binary grs 1915+105.

• Grant number: 07/03606-6
• Support Opportunities: Regular Research Grants - Publications - Scientific article
• Start date: December 01, 2007
• End date: June 30, 2008
• Field of knowledge: Physical Sciences and Mathematics - Astronomy
• Principal Investigator: Irapuan Rodrigues de Oliveira Filho
• Grantee: Irapuan Rodrigues de Oliveira Filho
• Host Institution: Instituto de Pesquisa e Desenvolvimento (IP&D). Universidade do Vale do Paraíba (UNIVAP). São José dos Campos , SP, Brazil

Abstract

The space velocity of a stellar black hole encodes the history of its formation and evolution. Here we measure the 3-dimensional motion of the microquasar GRS 1915+105, using a decade of astrometry with the NRAO Very Long Baseline Array, together with the published radial velocity. The velocity in the Galactic Plane deviates from circular rotation by 53–80±8 km/s, where the range covers any specific distance from 6–12 kpc. Perpendicular to the plane, the velocity isonly 10±4 km s−1. The peculiar velocity is minimized at a distance 9–10 kpc, and is then nearly in the radial direction towards the Galactic Center. We discuss mechanisms for the origin of the peculiar velocity, and conclude that it is most likely a consequence of Galactic velocity diffusion on this old binary, rather than the result of a supernova kick during the formation of the 14 M⊙ black hole. Finally, a brief comparison is made with 4 other BH binaries whose kinematics are well determined. (AU)