TY - JOUR
T1 - The 67 Hz feature in the black hole candidate GRS 1915+105 as a possible "diskoseismic" mode
AU - Nowak, Michael A.
AU - Wagoner, Robert V.
AU - Begelman, Mitchell C.
AU - Lehr, Dana E.
PY - 1997
Y1 - 1997
N2 - The Rossi X-Ray Timing Explorer has made feasible for the first time the search for high-frequency (≳100 Hz) periodic features in black hole candidate (BHC) systems. Such a feature, with a 67 Hz frequency, recently has been discovered in the BHC GRS 1915+105 (Morgan, Remillard, & Greiner). This feature is weak (rms variability ∼0.3%-1.6%), stable in frequency (to within ∼2 Hz) despite appreciable luminosity fluctuations, and narrow (quality factor Q ∼ 20). Several of these properties are what one expects for a "diskoseismic" g-mode in an accretion disk about a 10.6 M· (nonrotating) to 36.3 M0 (maximally rotating) black hole (if we are observing the fundamental-mode frequency). We explore this possibility by considering the expected luminosity modulation, as well as possible excitation and growth mechanisms-including turbulent excitation, damping, and "negative" radiation damping. We conclude that a diskoseismic interpretation of the observations is viable.
AB - The Rossi X-Ray Timing Explorer has made feasible for the first time the search for high-frequency (≳100 Hz) periodic features in black hole candidate (BHC) systems. Such a feature, with a 67 Hz frequency, recently has been discovered in the BHC GRS 1915+105 (Morgan, Remillard, & Greiner). This feature is weak (rms variability ∼0.3%-1.6%), stable in frequency (to within ∼2 Hz) despite appreciable luminosity fluctuations, and narrow (quality factor Q ∼ 20). Several of these properties are what one expects for a "diskoseismic" g-mode in an accretion disk about a 10.6 M· (nonrotating) to 36.3 M0 (maximally rotating) black hole (if we are observing the fundamental-mode frequency). We explore this possibility by considering the expected luminosity modulation, as well as possible excitation and growth mechanisms-including turbulent excitation, damping, and "negative" radiation damping. We conclude that a diskoseismic interpretation of the observations is viable.
KW - Black hole physics
KW - X-rays: stars
UR - https://www.scopus.com/pages/publications/21744457831
U2 - 10.1086/310534
DO - 10.1086/310534
M3 - Article
AN - SCOPUS:21744457831
SN - 0004-637X
VL - 477
SP - L91-L94
JO - Astrophysical Journal
JF - Astrophysical Journal
IS - 2 PART II
ER -