Astronomy and Astrophysics – Astrophysics
Scientific paper
2001-02-23
Astronomy and Astrophysics
Astrophysics
3 pages with 1 eps figure, aipproc.cls. To appear in Proceedings of the 20th Texas Symposium on Relativistic Astrophysics, Aus
Scientific paper
10.1063/1.1419613
We present analytical and numerical solutions which describe a hot, viscous, two-temperature accretion flow onto a neutron star or any other compact star with a surface. We assume Coulomb coupling between the protons and electrons, and free-free cooling from the electrons. Outside a thin boundary layer, where the accretion flow meets the star, we show that there is an extended settling region which is well-described by two self-similar solutions: (1) a two-temperature solution which is valid in an inner zone $r\le10^{2.5}$ ($r$ is in Schwarzchild units), and (2) a one-temperature solution at larger radii. In both zones, $\rho\propto r^{-2}, \Omega\propto r^{-3/2}, v\propto r^0,\ T_p\propto r^{-1}$; in the two-temperature zone, $T_e\propto r^{-1/2}$. The luminosity of the settling zone arises from the rotational energy of the star as the star is braked by viscosity; hence the luminosity is independent of $\dot M$. The settling solution is convectively and viscously stable and is unlikely to have strong winds or outflows. The flow is thermally unstable, but the instability may be stabilized by thermal conduction. The settling solution described here is not advection-dominated, and is thus different from the self-similar ADAF found around black holes. When the spin of the star is small enough, however, the present solution transforms smoothly to a (settling) ADAF.
No associations
LandOfFree
Self-Similar Hot Accretion Flow onto a Neutron Star does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with Self-Similar Hot Accretion Flow onto a Neutron Star, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Self-Similar Hot Accretion Flow onto a Neutron Star will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-465374