High Energy Astrophysics -
Fall
2006
Homework #5 - due October 19
1. Using a plotting program of your choice, plot the surface
density,
temperature, and energy dissipation rate versus radius of a disk
surrounding a black hole. Be sure to choose suitable
dimensionless units for all four quantities. Cover a radius range
of 0 to 100 ri.
2. Derive an equation for the apparent speed of a jet moving at a
physical speed v and at an
angle theta relative to our line of sight.
3. Find the accretion luminosity in terms of the Eddington luminosity
for a 1 solar mass black hole and a 106 solar mass black hole accreting
from a medium with a density of 10-24 g/cm3 and a sound
speed of 10 km/s. Assume that the efficiency for the
conversion of mass to energy is 0.1.