# Line Emission from HD204598b

## Blackbody luminosity

We have previously calculated the blackbody luminosity from the Intensity as

where

which gives

where

and

has units of ergs/s/HzWe also have from Bourrier et al, a theoretical line emission curve for Lyman Alpha

"Theoretical instrinsic stellar emission line profile scaled to the Earth distance"

with units of ergs/s/cm^{2}/A

After multiplying by 4*pi*47.1 pc ^{2} to get Luminosity per angstrom, we need to convert to Luminostiy per Hz

To go from

towe need to multiply by

So after some conversions, I get the following which shows the previously used black body, along with the line emission profile.

Now if I assume that the atmosphere is optically thin, and integrate the emission profile (+ continuum) over the absorption cross section -

where

and

This cutoff frequency is much higher than the Lyman Alpha wings… Which is not terribly surprising… Lyman Alpha ( even thermally broadened) will not ionize any hydrogen… So, I don't need to change the Ionization Routines (except to adjust the temperature if necessary etc…)

And creating synthetic emission lines - is just a matter of multiplying the background brightness at each wavelength by the emission profile…

The first row shows from left to right the data extracted from the plot in Bourrier et al and the spline fit, the same plot with the x-axis in Angstroms instead of km/s, and the Luminosity per frequency from the line emission as well as the black body.

The second row shows the brightness as a function of time and frequency assuming the Line emission profile as well as lineouts at various times and frequencies. (Time is ordered correctly in all of these plots)

# Meeting update

*** New problem module for OH231**

- Launch conical wind first for sometime then launch clump with the results of 1st step as background.
- compiled and ran. Some minor problems to be fixed..
- testing results.

***Rotating problem module for M2-9**

- try to reproduce the results in Gacia-Arredondo2004 paper
- latest updates

# Reading books and papers

I am learning radiation transfer in some depth.

http://arxiv.org/abs/1506.05121

This is a paper that I am also going to present in the coming journal club.

A very good literature is:

http://deepblue.lib.umich.edu/bitstream/handle/2027.42/60735/wollaber_1.pdf?sequence=1

I think radiation transfer is a very promising field because.

- It is under developed. There are many algorithms for optical thick and LTE (flux limited diffusion, variable Eddington tensor or M1 closure), there are also many algorithms for optical thin and non-LTE (analytic approximation or non-analytic approximation). But there is no efficient algorithm for both. Monte Carlo is an very interesting algorithm to learn and as the computer get more powerful, it will eventually become a global algorithm.

- It is in many problems. To name a few, star formation, stellar wind, ISM, binary evolution and galaxy evolution. If we solve the radiation transfer, we can apply it to those problem easily.

- In application, ICF and MCF both concern radiation transfer, high temperature engines will also consider radiation.

# Synthetic Absoprtion profiles for HD209458b

Normalized transmission as a function of velocity for gas in front of the stellar surface. The y-axis shows the time and there is a faint band from t=5 to t=7 hours that correspond to the time when the planet itself is in front of the star. The velocity is the projection of the gas velocity towards the camera - so positive velocities should correspond to shorter wavelengths and higher frequencies. The shifting to higher velocities at early times I believe can be attributed to the gas emitted from the day side that gets swept out in front of the planet and then gets accelerated outward by the stellar wind.

(Note the earlier version of this plot had the velocity scale incorrectly going from -300 to 300 km/s)

And here is a movie showing the emission at the center wavelength

# Updated Ring Model

The model and equations are described here: https://astrobear.pas.rochester.edu/trac/wiki/u/erica/magneticring