Testing Radiation Pressure

Radiation pressure was implemented with line center radiation only, no Doppler shift taken into account. Some tests follow.

Static constant density

Balanced gravitational acceleration with radiation pressure on a constant neutral density environment: link. Get an error of ~0.1% acceleration over many timescales.

Clump with Ionization & Radiation Pressure

Density

Ionizing Flux

The Lyman-\alpha flux is being saved incorrectly at the moment, so no plot available yet.

Legend:

Radiation Pressure	Ionization
Rad Pressure & Ionization	Rad Pressure, Ionization & Gravity	(numbers below don't apply - just fun to watch)

Lyman-\alpha flux	5x1013 phot/cm2/s
Ionizing flux	2x1011 phot/cm2/s

Planet

Parameter Space

Bolded boxes (in the table at the bottom of this page) are currently-planned runs. Would like to choose a 2x2 grid of high/low flux and high/low mass eventually; bolded and italicized box would be the natural extension of these.

Photon-limited regime

The small planet mass ends up with an infinitely extended atmosphere in the hydrostatic solution. It seems like it will be difficult to simulate all the way down to the photon-limited regime in general, due to the small mass required.

Recombination-limited regime

A first attempt at the high-flux case results in the \tau = 1 surface coming to rest against the reset radius:

Either we need to adjust the ramping function, or (what I'm in the process of) we need to restart from a stable low-flux equilibrium state and ramp the flux up from there to the desired value (following a similar, but perhaps wider, ramping function). Another solution could be to initialize some part of the atmosphere with something like an equilibrium outflow, so that the neutrals are continuously replenished at the planet's surface from the beginning of the simulation.

Energy-limited regime

Top view

Side view

Contour key:

Purple	Mach 1 surface
Black	\tau = 1
Green	Rib
Red	RP
Yellow	Rob
Brownish-red	R_{\Omega}

All regimes

Physical Parameters

\rho_P	1.32443x10-16 g/cc
T_P	3x103 K
R_P	2.14559 RJ
M_*	1.350 Msun

lRotate	T
lStellarGravity	T
TimeScale	8.3825 hours
lScale	1.5x1010 cm

Simulation Parameters

BaseRes	(32, 32, 32)
MaxLevel	3
lRampFlux	T
HalfTime	4
RampSpeed	2.65
Zones/RP	32
frames/CT	100
Extent	(37, -10, -10, 57, 10, 10)
Physical Extent	(5.55x1011, -1.5x1011, -1.5x1011, 8.55x1011, 1.5x1011, 1.5x1011) cm

0.04747 AU (For reasonable values of MP, Porb = ~3.25 days)
	0.263435 MJ	MJ	0.015 MJ	GJ436b (RP = 0.38 RJ, MP = 0.07 MJ)
4x102 erg/cm2/s	R_{Hill} = 1.83 R_P R_\Omega = 2.64R_P \lambda_P = 2.6369 R_{sonic} = 1.32 R_P Energy-limited	R_{Hill} = 2.86R_P R_\Omega = 2.65R_P \lambda_P = 10 R_{sonic} = 5 R_P Recombination-limited	R_{Hill} = 0.705 R_P R_\Omega = 2.65 R_P \lambda_P = 0.15 R_{sonic} = 0.075 R_P Photon-limited	R_{Hill} = 6.65 R_P R_\Omega = 14.94 R_P \lambda_P = 3.96 R_{sonic} = 1.98 R_P Energy-limited
4x105 erg/cm2/s	R_{Hill} = 1.83 R_P R_\Omega = 2.64R_P \lambda_P = 2.6369 R_{sonic} = 1.32 R_P Recombination-limited	R_{Hill} = 2.86R_P R_\Omega = 2.65R_P \lambda_P = 10 R_{sonic} = 5 R_P Recombination-limited	R_{Hill} = 0.705 R_P R_\Omega = 2.65 R_P \lambda_P = 0.15 R_{sonic} = 0.075 R_P Recombination-limited	R_{Hill} = 6.65 R_P R_\Omega = 14.94 R_P \lambda_P = 3.96 R_{sonic} = 1.98 R_P Energy-limited
4x106 erg/cm2/s	R_{Hill} = 1.83 R_P R_\Omega = 2.64R_P \lambda_P = 2.6369 R_{sonic} = 1.32 R_P Recombination-limited	R_{Hill} = 2.86R_P R_\Omega = 2.65R_P \lambda_P = 10 R_{sonic} = 5 R_P Recombination-limited	R_{Hill} = 0.705 R_P R_\Omega = 2.65 R_P \lambda_P = 0.15 R_{sonic} = 0.075 R_P Recombination-limited	R_{Hill} = 6.65 R_P R_\Omega = 14.94 R_P \lambda_P = 3.96 R_{sonic} = 1.98 R_P Recombination-limited

0.02887 AU (For reasonable values of MP, Porb = ~1.54 days)
	0.263435 MJ	MJ	0.015 MJ	GJ436b (RP = 0.38 RJ, MP = 0.07 MJ)
4x102 erg/cm2/s	R_{Hill} = 1.11 R_P R_\Omega = 1.26R_P \lambda_P = 2.6369 R_{sonic} = 1.32 R_P Energy-limited	R_{Hill} = 1.74R_P R_\Omega = 1.25R_P \lambda_P = 10 R_{sonic} = 5 R_P Recombination-limited	R_{Hill} = 0.429 R_P R_\Omega = 1.26 R_P \lambda_P = 0.15 R_{sonic} = 0.075 R_P Photon-limited	R_{Hill} = 4.05 R_P R_\Omega = 7.09 R_P \lambda_P = 3.96 R_{sonic} = 1.98 R_P Energy-limited
4x105 erg/cm2/s	R_{Hill} = 1.11 R_P R_\Omega = 1.26R_P \lambda_P = 2.6369 R_{sonic} = 1.32 R_P Recombination-limited	R_{Hill} = 1.74R_P R_\Omega = 1.25R_P \lambda_P = 10 R_{sonic} = 5 R_P Recombination-limited	R_{Hill} = 0.429 R_P R_\Omega = 1.26 R_P \lambda_P = 0.15 R_{sonic} = 0.075 R_P Recombination-limited	R_{Hill} = 4.05 R_P R_\Omega = 7.09 R_P \lambda_P = 3.96 R_{sonic} = 1.98 R_P Energy-limited
4x106 erg/cm2/s	R_{Hill} = 1.11 R_P R_\Omega = 1.26R_P \lambda_P = 2.6369 R_{sonic} = 1.32 R_P Recombination-limited	R_{Hill} = 1.74R_P R_\Omega = 1.25R_P \lambda_P = 10 R_{sonic} = 5 R_P Recombination-limited	R_{Hill} = 0.429 R_P R_\Omega = 1.26 R_P \lambda_P = 0.15 R_{sonic} = 0.075 R_P Recombination-limited	R_{Hill} = 4.05 R_P R_\Omega = 7.09 R_P \lambda_P = 3.96 R_{sonic} = 1.98 R_P Recombination-limited