1. Dust. LyGalaxies Nyborg, 2008
Under the supervision of collaborating with
Nyborg, 2008
Dark Cosmology Centre | Niels Bohr Institutet | Københavns Universitet

2. Lyman a Cooling radiation (~10%) Stellar sources (~90%)
Metagalactic field (~1%)
At z = 3 - 4, in the context of galaxy formation, Lyman alpha is produced in a number of ways, the most significant being the ionization and subsequent recombination of hydrogen in the vicinity of young, massive stars. PP67: This should make young galaxies visible. Still, however, for 3 decades none were observed. 
Young galaxies should be
visible (Partridge & Peebles, 1967)

3. Analytical models Osterbrock (1962) Harrington (1973) Neufeld (1990)
Models were constructed in order to try to explain the null results
Osterbrock (1962)
Harrington (1973)
Neufeld (1990)

4. Analytical models Dijkstra (2006)
Recently extended to more realistic models
Dijkstra (2006)

5. Reality
Although the model give us much insight into the physical properties of galaxies and their formation, it is not obvious how consistent their results are with those of more realistic models

6. Cosmological simulations
Razoumov & Sommer-Larsen (2006)
Sommer-Larsen et al. (2003)
Sommer-Larsen (2006)

7. Monte Carlo L, T, nHI , vbulk , Zi i = C, N, O, Mg, Si, S, Ca, Fe
Interpolate SPH-particle onto grid. The following results are from a uniform grid, 512^3. Code is now able to assume an adaptive grid, giving even higher res. where needed

8. Monte Carlo
Emit photon

9. Monte Carlo
Emit photon 
Determine t

10. Monte Carlo
Emit photon 
Determine t 
Determine uatom

11. Monte Carlo    Emit photon Determine t Determine uatom ^
Determine n
Escape!

12. Galaxies. Multifarious
Evolutionary sequence?
DLA  LAE  LBG  DRG  SMG?
Selection effects?
LBGs/DLAs probe two diff. ends of hi-z LF
Viewing angle?

13. 

14. 

15. 

16. Surface brightness profiles

17. Surface brightness profiles

19. Spectra 

20. Spectra 

21. Inhomogeneous medium

22. SMC/LMC dust

23. Preliminary, shit-hot new results
fesc = 0.11

24. Preliminary, shit-hot new results
fesc = 0.10

25. Preliminary, shit-hot new results
fesc = 0.21

26. Preliminary, shit-hot new results
fesc = 0.21

27. Summary Ly scattering responsible for extended halo
Ly line profile may reveal gas kinematics
Line is broadened ~1000 km s-1
Anisotropic escape of radiation may explain differences in observed properties, and may even link different types of galaxies
This effect is strengthened by dust
Escape fraction may vary from 10% to 40% (but don’t put your money on this yet)