2000/01/21 by Dimitrios Psaltis, Colin Norman, Psaltis, Dimitrios +1
Earth and Planetary Sciences · Physics and Astronomy · #Astrophysical Phenomena and Observations #Astrophysics (astro-ph) #FOS: Physical sciences #High-pressure geophysics and materials #Pulsars and Gravitational Waves Research #astro-ph
paper · pdf · doi:10.48550/arxiv.astro-ph/0001391
21 pages, 4 figures; original version submitted to the Astrophysical Journal on 8/6/99
arxiv created 2000/01/21 · openalex publication_date 2000/01/21 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
Accreting neutron stars and black holes share a number of rapid variability\ncharacteristics, such as quasi-periodic oscillations and broad-band noise. The\nfrequencies of these features were recently shown to be comparable to\nfundamental general relativistic frequencies of perturbed test-particle orbits\nnear the compact objects. In this paper we propose a dynamical model for\nproducing modulations in the inner disk properties at these characteristic\nfrequencies. We postulate that a transition radius exists in the accretion disk\nclose to the compact object and investigate its response to a broad spectrum of\ndensity fluctuations. We find that the transition radius acts as a low\nband-pass filter with a broadband response that is constant at frequencies\nlower than the inverse radial drift timescale and decreases above it as the\ninverse of the frequency. Moreover, the response shows strong resonances at\nfrequencies nearly equal to the orbital, periastron-precession, and\nnodal-precession frequencies, thereby accounting for the observed power-density\nspectra of accreting compact objects and the correlations between their\ncharacteristic frequencies.\n