Статья

Dynamical Evidence for a Black Hole in the Microquasar XTE J1550−564

Jerome A. OroszAstronomical Institute, Utrecht University, Postbus 80000, 3508 TA Utrecht, NetherlandsPaul J. GrootHarvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138Michiel van der KlisAstronomical Institute “Anton Pannekoek,” University of Amsterdam, and Center for High-Energy Astrophysics, Kruislaan 403, 1098 SJ Amsterdam, NetherlandsJeffrey E. McClintockAstronomical Institute, Utrecht University, Postbus 80000, 3508 TA Utrecht, NetherlandsMichael R. GarciaAstronomical Institute, Utrecht University, Postbus 80000, 3508 TA Utrecht, NetherlandsPing ZhaoAstronomical Institute, Utrecht University, Postbus 80000, 3508 TA Utrecht, NetherlandsRaj K. JainDepartment of Physics, Yale University, P.O. Box 208120, New Haven, CT 06520-8120Charles D. BailynDepartment of Astronomy, Yale University, P.O. Box 208101, New Haven, CT 06520-8101Ronald A. RemillardCenter for Space Research, Massachusetts Institute of Technology, Cambridge, MA 02139-4307

2002en

ABI

Аннотация

Optical spectroscopic observations of the companion star (type G8IV to K4III) in the microquasar system XTE J1550-564 reveal a radial velocity curve with a best fitting spectroscopic period of P_sp = 1.552 +/- 0.010 days and a semiamplitude of K_2 = 349 +/- 12 km/s. The optical mass function is f(M) = 6.86 +/- 0.71 solar masses (1 sigma). We tentatively measure the rotational velocity of the companion star to be V_rot*sin(i) = 90 +/- 10 km/s, which when taken at face value implies a mass ratio of Q = M_1/M_2 = 6.6 (+2.5 / -1.6) (1 sigma), using the above value of K_2. We derive constraints on the binary parameters from simultaneous modelling of the ellipsoidal light and radial velocity curves. We find the most likely value of the mass of the compact object is 9.41 solar masses with a 1 sigma range of 8.36 < M_1 < 10.76 solar masses. If we apply our tentative value of V_rot*sin(i) = 90 +/- 10 km/s as an additional constraint in the ellipsoidal modelling, we find the most likely value of the mass of the compact object is 10.56 solar masses with a 1 sigma range of 9.68 < M_1 < 11.58 solar masses. In either case the mass of the compact object is well above the maximum mass of a stable neutron star, and we therefore conclude XTE J1550-564 contains a black hole.

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Идентификаторы

DOI: 10.1086/338984

Цитирования и источники

Цитирований: 3Использованных источников: 0

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