Open AccessOn the formation rate of close binaries consisting of a super‐massive black hole and a white dwarf
Author(s) -
Ivanov P. B.
Publication year - 2002
Publication title -
monthly notices of the royal astronomical society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.058
H-Index - 383
eISSN - 1365-2966
pISSN - 0035-8711
DOI - 10.1046/j.1365-8711.2002.05733.x
Subject(s) - physics , astrophysics , compact star , white dwarf , black hole (networking) , galaxy , radius , gravitational wave , amplitude , cusp (singularity) , primordial black hole , binary black hole , astronomy , spin flip , stars , geometry , computer network , routing protocol , routing (electronic design automation) , computer security , mathematics , quantum mechanics , computer science , link state routing protocol
The formation rate of a close binary consisting of a super‐massive black hole and a compact object (presumably a white dwarf) in galactic cusps is calculated with the help of the so‐called loss cone approximation. For a power‐law cusp of radius r a , the black hole mass M ∼ 10 6 M ⊙ , and the fraction of the compact objects δ∼ 0.1 , this rate . The function K ( p ) depends on parameter p determining the cusp profile, and for the standard cusp profiles with p = 1/4, K ( p ) ∼ 2 . We estimate the probability Pr of finding of a compact object orbiting around a black hole with the period P in one particular galaxy to be Pr ∼ 10 −7 [( P /10 3 s)/( M /10 6 M ⊙ )] 8/3 [( M /10 6 M ⊙ )/( r a /1 pc)] 3/2 . The object with the period P ∼ 10 3 s emits gravitational waves with amplitude sufficient to be detected by the LISA‐type gravitational wave antenna from the distance ∼10 3 Mpc . Based on estimates of masses of super‐massive black holes in nearby galaxies, we speculate that LISA would detect several such events during its mission.