Changes between Version 15 and Version 16 of u/erica/RadFeedback
- Timestamp:
- 11/19/15 14:04:27 (9 years ago)
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u/erica/RadFeedback
v15 v16 7 7 == Accretion Luminosity == 8 8 9 The amount of energy deposited into the kernel around a sink is intuitively given by the accretion energy. As infalling material hits the surface of the star, its kinetic energy is converted to heat. For spherical symmetry, a gas parcel starting from rest and freely falling to the star from infinity will have its kinetic energy and gravitational energy balanced once the parcel reaches the star:9 The amount of energy deposited into the kernel around a sink is intuitively given by the accretion energy. As infalling material hits the surface of the star, its kinetic energy is converted to heat. For spherical symmetry, a gas parcel starting from rest and freely falling to the star from infinity will have: 10 10 11 11 [[latex($\frac{1}{2} m v_{ff}^2 = \frac{GmM_{*}}{R_{*}}$)]] 12 12 13 As the material strikes the surface of the star (i.e. is accreted) the kinetic energy is converted to heat. For an accretion rate [[latex($\dot{m}$)]], the rate at which this heat is produced, or the luminosity L, is given by:13 at the surface of the star. As the material strikes the surface of the star (i.e. is accreted) the kinetic energy is converted to heat. For an accretion rate [[latex($\dot{m}$)]], the rate at which this heat is produced, or the luminosity L, is given by: 14 14 15 15 [[latex($ L = \frac{1}{2}\dot{m} v_{ff}^2 = \frac{G\dot{m}M_{*}}{R_{*}}$)]]