Open AccessSelf‐similar hot accretion on to a spinning neutron star: matching the outer boundary conditions
Author(s) -
Narayan Ramesh,
Medvedev Mikhail V.
Publication year - 2003
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.1365-8711.2003.06747.x
Subject(s) - physics , spinning , neutron star , radius , accretion (finance) , astrophysics , star (game theory) , boundary (topology) , angular velocity , boundary value problem , mechanics , classical mechanics , mathematical analysis , mechanical engineering , computer security , mathematics , quantum mechanics , computer science , engineering
Medvedev & Narayan have described a hot accretion flow on to a spinning neutron star in which the gas viscously brakes the spin of the star. Their self‐similar solution has the surprising property that the density, temperature and angular velocity of the gas at any radius are completely independent of the outer boundary conditions. Hence, the solution cannot be matched to a general external medium. We resolve this paradoxical situation by showing that there is a second self‐similar solution which bridges the gap between the original solution and the external medium. This new solution has an extra degree of freedom which permits it to match general outer boundary conditions. We confirm the main features of the analytical results with a full numerical solution.