1. Recycling the Intergalactic Medium
Do Intergalactic HI Clouds Exist ?
A recycled IGM talk
from
the IAU Symposium on
Recycling the Intergalactic Medium
z = 8
z = 0

2. The Short Answer: NEUTRAL NO ! Do INTERGALACTIC HI CLOUDS exist ?
Hydrogen
Do INTERGALACTIC HI CLOUDS exist ?
The Short Answer:
NO !
z = 8
z = 0

3. The Short Story: NEUTRAL why should they exist ?
Hydrogen
INTERGALACTIC HI CLOUDS
The Short Story: HI
definition …
why should they exist ?
why should they NOT exist?

4. HI Map of M81 Group
Yun, Ho & Lo 1994
M82
M81
NGC 3077

5. ??? INTERGALACTIC ?????? HI Map of M81 Group
Yun, Ho & Lo 1994
??? INTERGALACTIC ??????
Pristine, Primordial gas !!??
NO STARS !!!???

6. HI Map of M81 Group Pristine, Primordial gas ??
Yun, Ho & Lo 1994
Pristine, Primordial gas ??
Fuel ongoing Star Formation
Solve metal abundance
problems….
Trace “dark” Dark Matter
Halos

7. more HI in M96
than the Ring
(Schneider etal 1989)

8. HI contours

9. F Stars & HI gas Cartoon for Z = 0 Sea of ionized baryons
?? Just HI ??
Stars & HI gas
i.e.

10. Radio spectroscopy

11. Giovanelli-
Haynes
“Virgo Cloud”
Chengalur et al 1995 .

12. Limits on I.G. HI Clouds:
Fisher & Tully “not cosmologically significant”

13. Limits on I.G. HI Clouds: <
Fisher & Tully “not cosmologically significant”
1990 Briggs NIGClouds
NGalaxies
<

14. Limits on I.G. HI Clouds: <
Fisher & Tully “not cosmologically significant”
1990 Briggs NIGClouds
NGalaxies
<
2000 Zwaan (PhD Thesis) HI Mass Function

15. Arecibo: HI content according to galaxy mass
(Zwaan et al 1997)
Limits on
I.G.Clouds

16. Limits on I.G. HI Clouds:
Fisher & Tully “not cosmologically significant”
1990 Briggs NIGClouds <
NGalaxies
2000 Zwaan (PhD Thesis) HI Mass Function
2003 Koribalski/Zwaan ET AL… HIPASS

17. HIPASS … Parkes Telescope
Consortium: ATNF, Melbourne, Cardiff, RSAA +

18. Limits on I.G. HI Clouds: 1000’s of galaxies… no I.G. Clouds
Fisher & Tully “not cosmologically significant”
1990 Briggs NIGClouds <
NGalaxies
2000 Zwaan (PhD Thesis) HI Mass Function
2003 Koribalski/Zwaan ET AL… HIPASS
1000’s of galaxies… no I.G. Clouds

19. MHI Msolar = 10 – 20 Loptical Lsolar ??? I.G. HI Clouds
HIPASS result… Warren, Jerjen, ET AL
…. a few extremely HI rich galaxies
MHI
Loptical
Lsolar
Msolar
= 10 – 20
??? I.G. HI Clouds
with stellar contamination ???
B.Warren: “They’re galaxies !”

20. … that’s the observational evidence.

21. .…. ionized……
CMB
Big Bang Nucleosynthesis+WMAP

22. damped
Lyman-a
abs-lines
21cm
Line
Studies
(HIPASS)

23. W
Tot
1/3300 W M
-0.5

24. Recombination
competes with
Re-ionization

25. Time scales for Recombination in IGM…
t = n /R
= n /(n n a ) e p
recomb
recomb e
= 1 /( n a ) p
recomb
= T /( n 2 x ) sec p
1/2
-11
but, n ~ n proportional ~ (1+z) 3 p
baryon
Remember to comment on ASSUMPTION of average density…. Clearly there are over and under densities…
t proportional T /(1+z)
recomb 3
1/2

26. Tcmb Tkinetic Temperature vs Redshift Onset of sources of
ionizing radiation
Tcmb
Tkinetic

27. Temperature vs Redshift
first ionizing
sources H

28. Temperature vs Redshift
QSOs
/AGN He
first ionizing
sources H

29. Tkinetic Recombination Time (mean density) 1010yr 109yr Age of
low density
109yr
Age of
Universe
Galaxy Disk Gas
Trec ~ 105yr
107yr

30. F Hydrogen must be confined ! Stars & HI gas Z = 0
Sea of ionized baryons F
?? Just HI ??
Stars & HI gas
i.e.

31. Barkana & Loeb:
Dark Matter Halo
Mass Function
Z =

32. Integral Mass
Content
per logarithmic
interval

33. Mass Functions

34. Mass Functions DM
baryons
Clusters

35. Mass Functions

36. Mass Functions

37. Mass Functions
Missing
bound
baryons

38. F Fate of baryons in small halos…? Z = 0 Sea of ionized baryons
i.e.
If massive,
get

39. F Fate of baryons in small halos… Z = 0 Sea of ionized baryons
Early small halo formation… gas expelled by supernovae
Late small halo formation… IGM too hot to be captured by a low mass halo
Mhalo ~108Mo => Tvir ~ K

40. Large mass halos Star Formation Galaxies
Conclusions:
Large mass halos Star Formation Galaxies
Early Low mass halos Star Formation ISM Lost
Late Low mass halos never capture gas, (No Star
Formation)
No Intergalactic Neutral Hydrogen Clouds at Z=0
… need to recover low metalicity IONIZED IGM & Halo clouds…

44. NGC 1512: Color coded velocity field

47. NGC 3344: HI Gas distribution

48. NGC 3344: HI velocity field

49. CIV MgII/ Lyman limit DLA (HI) (CII, FeII, SiII, …)
Relative interception cross sections for QSO Absorption Lines …
CIV
DLA (HI)
MgII/ Lyman limit
(CII, FeII, SiII, …)