1. Intergalactic transmission and its impact on the Lyman a line
Peter Laursen
Potsdam, 2011
Oskar Klein Centre | Inst. för Astronomi | Stockholms Universitet

2. Lyman a modeling Theoretically Numerically Osterbrock (1962)
Adams (1972)
Harrington (1973)
Neufeld (1990, 1991)
Loeb & Rybicky (1999)
Dijkstra+ (2006)
Numerically
Auer (1965)
Avery & House (1968)
Loeb & Rybicky (1999)
Ahn et al. (2001, 2002)
Zheng & Miralda-Escudé (2002)
Cantalupo+ (2005)
Dijkstra+ (2006)
Hansen & Oh (2006)
Tasitsiomi (2006)
Verhamme+ (2006)
Laursen+ (2007, 2009)
Barnes+ (2010, 2011)
Zheng+ (2010, 2011)

3. Standard approach • Ignore • Remove blue half
• Reduce full line by some factor e–<t>
• Remove blue half

4. Numerical approach
Cosmological N-body+hydro simulation (SPH, Sommer-Larsen et al. 2003, 2006)
+ ionizing UV RT (Razoumov & Sommer-Larsen 2006, 2007)
+ hi-res resimulations of interesting regions
+ galactic Monte Carlo Ly RT with dust
+ IGM RT

5. Galactic RT – MOCALATA*
Each cell:
nHI, nHII, T, vbulk, LLya, Zi ⇒nd
* PL et al. 2009, ApJ, 696, 853 and 2009, ApJ, 704, 1640

6. Galactic RT – MOCALATA*
No scattering
With scattering
Including dust
* PL et al. 2009, ApJ, 696, 853 and 2009, ApJ, 704, 1640

7. Galactic RT – MOCALATA*
* PL et al. 2009, ApJ, 696, 853 and 2009, ApJ, 704, 1640

8. Intergalactic RT – IGMTRANSFER*
* PL et al. 2011, ApJ, 728, 52; the code can be downloaded from

9. Intergalactic RT – IGMTRANSFER*
* PL et al. 2011, ApJ, 728, 52; the code can be downloaded from

10. Intergalactic RT – IGMTRANSFER*
* PL et al. 2011, ApJ, 728, 52; the code can be downloaded from

11. Intergalactic RT – IGMTRANSFER*
z = 3.5
* PL et al. 2011, ApJ, 728, 52; the code can be downloaded from

12. Intergalactic RT – IGMTRANSFER*
z = 5.8
* PL et al. 2011, ApJ, 728, 52; the code can be downloaded from

13. Intergalactic RT – IGMTRANSFER*
z = 6.5
* PL et al. 2011, ApJ, 728, 52; the code can be downloaded from

14. Transmission function

15. The origin of the dip
Velocity field
Density field

16. Impact on the Lya profile
z = 3.5
Spectrum escaping galaxy
Transmission function
Observed spectrum

17. Impact on the Lya profile
z = 3.5

18. Impact on the Lya profile
z = 5.8

19. Impact on the Lya profile
z = 6.5

20. Transmitted fraction
z = 3.5

21. Transmitted fraction
z = 5.8

22. Transmitted fraction
z = 6.5

23. Alternative to outflow model?
z = 3 – 4 ?
However, as Roberto Maiolino mentioned yesterday, …
Verhamme et al. 2008, A&A, 491, 89

24. Probing the very first galaxies
z = 8.8
Ultra-VISTA
PIs Jim Dunlop, Marijn Franx, Johan Fynbo, & Olivier LeFèvre

25. Probing the very first galaxies
z = 8.8
Compare with Dijkstra & Wyithe 2010, MNRAS, 408, 352: ~5%

26. Probing the Epoch of Reionization
Songaila 2004, ApJ, 127, 2598 43

27. Probing the Epoch of Reionization44

28. Summary
IGM absorption may explain at least some of the asymmetric Ly profiles •
Transmitted fractions are
at z = 3.5 •
–34
–18
at z = 5.8
at z = 6.5
–??
0.05+?? at z = 8.8
Reionization may have initiated earlier than probed by WMAP •

29. Extra stuff

30. Extra stuff

31. Extra stuff With Hannes Jensen (OKC), Garrelt Mellema (OKC),
Ilian Iliev (U. of Sussex), &
Paul Shapiro (U. of Texas)

32. Extra stuff

33. Extra stuff