On page 5 of the link http://www.maths.qmul.ac.uk/~rpn/ASTM735/Week9-powerpoint.pdf , there are 2 graphs. I'm referring to the 2nd graph (the one with the flared disk fit). What is the green plot supposed to represent?
On page 26 of http://www.maths.qmul.ac.uk/~rpn/ASTM735/Week7.pdf , it claims that the signal-noise can be improved by integrating over long time periods since the noise amplitude scales with \frac{1}{\sqrt{t}} for Gaussian statistics.
Can someone explain that to me?
Page 26 of http://www.maths.qmul.ac.uk/~rpn/ASTM735/Week7.pdf claims that stellar jitter can be caused by the convective motions in the stellar photosphere.
Can someone explain that to me as I don't understand it?
Tm = \frac{dj}{dt}
where Tm is the torque per unit mass, and j = R2Ω(R) which is the specific angular momentum (angular momentum per unit mass)
It may be shown that
\frac{dj}{dt} = \frac{∂j}{∂t} + (v.\nabla)j (convective derivative)
= vR\frac{∂j}{∂R} [equation (68)...
http://www.maths.qmul.ac.uk/~rpn/ASTM735/lecture3.pdf
The diagram on page 26 is the accretion disc.
The torque acting on the inner edge of the ring (the one that has a thickness of dR in the diagram) is
RFin = -2\piR3\nuƩ\frac{dΩ}{dR}
The torque acting on the outer edge of the...
At the vertical direction, shoudn't the gravitational force be -\frac{GM}{z^{2}} instead of \frac{GMz}{(R^{2} + z^{2})^{3/2}} as the gravitational force is acting in the z direction.
This is regarding an accretion disc orbiting a star. In the z (vertical) direction there is a hydrostatic equilibrium.
\frac{1}{ρ}\frac{∂P}{∂z} = -\frac{GMz}{(R^{2} + z^{2})^{3/2}}
The right hand side of the expression is the Gravitational potential energy and the left side is the pressure...