dark-cosmology.dk /~pela

www.dark-cosmology.dk/~pela

Nyborg, 2008

Dust. LyGalaxies

Dark Cosmology Centre | Niels Bohr Institutet | Københavns Universitet

2

Lyman Cooling radiation (~10%)

Stellar sources (~90%)

Metagalactic field (~1%)

Young galaxies should bevisible (Partridge & Peebles, 1967)

3

Analytical models

Osterbrock (1962)Harrington (1973)Neufeld (1990)

4

Analytical models

Dijkstra (2006)

5

Reality

6

Cosmological simulations

Sommer-Larsen et al. (2003)Sommer-Larsen (2006)

Razoumov & Sommer-Larsen (2006)

7

Monte CarloL, T, nHI ,

vbulk , Zi

i = C, N, O, Mg, Si, S, Ca, Fe

8

Emit photon

Monte Carlo

9

Emit photon

Determine

Monte Carlo

10

Emit photon

Determine uatom

Determine

Monte Carlo

11

Emit photon

^Determine n

Determine uatom

Determine

Escape!

Monte Carlo

12

Galaxies. Multifarious

DLA LAE LBG DRG SMG?Evolutionary sequence?

Viewing angle?

Selection effects?LBGs/DLAs probe two diff. ends of hi-z LF

13

14

15

16

Surface brightness profiles

17

Surface brightness profiles

18

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)