- Access by Xinjiang University
Gravitational-wave signature of an inspiral into a supermassive horizonless object
Phys. Rev. D 71, 044015 – Published 10 February, 2005
DOI: https://doi.org/10.1103/PhysRevD.71.044015
Abstract
Event horizons are among the most intriguing of general relativity's predictions. Although on firm theoretical footing, direct indications of their existence have yet to be observed. With this motivation in mind, we explore here the possibility of finding a signature for event horizons in the gravitational waves (GWs) produced during the inspiral of stellar-mass compact objects (COs) into the supermassive () objects that lie at the center of most galaxies. Such inspirals will be a major source for LISA, the future space-based GW observatory. We contrast supermassive black holes with models in which the central object is a supermassive boson star (SMBS). Provided the COs interact only gravitationally with the SMBS, stable orbits exist not just outside the Schwarzschild radius but also inside the surface of the SMBS as well. The absence of an event horizon allows GWs from these orbits to be observed. Here we solve for the metric in the interior of a fairly generic class of SMBS and evolve the trajectory of an inspiraling CO from the Schwarzschild exterior through the plunge into the exotic SMBS interior. We calculate the approximate waveforms for GWs emitted during this inspiral. Geodesics within the SMBS surface will exhibit extreme pericenter precession and other features making the emitted GWs readily distinguishable from those emitted during an inspiral into a black hole.
Article Text
References (35)
- D. F. Torres, S. Capozziello, and G. Lambiase, Phys. Rev. D 62, 104012 (2000).
- Y. Yuan, R. Narayan, and M. J. Rees, Astrophys. J. 606, 1112 (2004).
- F. E. Schunck and A. R. Liddle, Phys. Lett. B 404, 25 (1997).
- H. Falcke, F. Melia, and E. Agol, Astrophys. J. 528, 13 (2000).
- D. Richstone et al., Nature (London) 395, A14 (1998).
- J. Kormendy and K. Gebhardt, in Proceedings of the 20th Texas Symposium on Relativistic Astrophysics, edited by H. Martel and J. C. Wheeler, AIP Conf. Proc. No. 586 (AIP, New York, 2002).
- E. Maoz, Astrophys. J. Lett. 447, L91 (1995).
- N. Weinberg, M. Milosavljevic, and A. Ghez, astro-ph/0404407.
- S. Sigurdsson and M. J. Rees, Mon. Not. R. Astron. Soc. 284, 318 (1997).
- S. Sigurdsson, Classical Quantum Gravity 14, 1425 (1997).
- T. D. Lee and Y. Pang, Phys. Rep. 221, 251 (1992).
- R. Friedberg, T. D. Lee, and Y. Pang, Phys. Rev. D 35, 3640 (1987).
- F. D. Ryan, Phys. Rev. D 55, 6081 (1997).
- M. Colpi, S. L. Shapiro, and I. Wasserman, Phys. Rev. Lett. 57, 2485 (1986).
- R. O. Hansen, J. Math. Phys. (N.Y.) 15, 46 (1974).
- F. D. Ryan, Phys. Rev. D 52, 5707 (1995).
- R. Friedberg, T. D. Lee, and Y. Pang, Phys. Rev. D 35, 3658 (1987).
- R. M. Wald, General Relativity (University of Chicago Press, Chicago, 1984).
- S. Chandrasekhar, The Mathematical Theory of Black Holes (Oxford University Press, New York, 1992).
- K. S. Thorne, Rev. Mod. Phys. 52, 299 (1980).
- C. W. Misner, K. S. Thorne, and J. A. Wheeler, Gravitation (W. H. Freeman and Company, New York, 1973).
- L. S. Finn and K. S. Thorne, Phys. Rev. D 62, 124021 (2000).
- K. Glampedakis, S. A. Hughes, and D. Kennefick, Phys. Rev. D 66, 064005 (2002).
- S. Babak, H. Fang, J. R. Gair, and K. Glampedakis (to be published).
- T. Creighton, J. R. Gair, S. A. Hughes, and M. Vallisneri (to be published).
- L. Barack and C. Cutler, Phys. Rev. D 69, 082005 (2004).
- J. R. Gair and K. Glampedakis (to be published).
- S. A. Teukolsky, Astrophys. J. 185, 635 (1973).
- M. Sasaki and T. Nakamura, Prog. Theor. Phys. 67, 1788 (1982).
- C. D. Murray and S. F. McDermott, Solar System Dynamics (Cambridge University Press, New York, 1999).
- K. Glampedakis and D. Kennefick, Phys. Rev. D 66, 044002 (2002).
- W. H. Press, Phys. Rev. D 15, 965 (1977).
- J. R. Gair and H. Fang (unpublished).
- M. Vallisneri, Phys. Rev. D 71, 022001 (2005).
- M. Kesden and M. Solomon (to be published).