Do Intergalactic HI Clouds Exist

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Do Intergalactic HI Clouds Exist ?
A recycled IGM talk from the IAU Symposium on
Recycling the Intergalactic Medium
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Do INTERGALACTIC HI CLOUDS exist ?
The Short Answer
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INTERGALACTIC HI CLOUDS
The Short Story

• definition
• why should they exist ?
• why should they NOT exist?

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HI Map of M81 Group
Yun, Ho Lo 1994
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HI Map of M81 Group
Yun, Ho Lo 1994
??? INTERGALACTIC ??????
Pristine, Primordial gas !!?? NO STARS
!!!???
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HI Map of M81 Group
Yun, Ho Lo 1994
Pristine, Primordial gas ??
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(Schneider etal 1989)
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HI contours
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Cartoon for Z 0
Sea of ionized baryons
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?? Just HI ??
Stars HI gas
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Radio spectroscopy
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Giovanelli- Haynes Virgo Cloud Chengalur
et al 1995
.
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Limits on I.G. HI Clouds

• Fisher Tully not cosmologically significant

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Limits on I.G. HI Clouds

• Fisher Tully not cosmologically significant
• 1990 Briggs NIGClouds 1
  
• NGalaxies 100

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Limits on I.G. HI Clouds

• Fisher Tully not cosmologically significant
• 1990 Briggs NIGClouds 1
  
• NGalaxies 100

2000 Zwaan (PhD Thesis) HI Mass Function
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Arecibo HI content according to galaxy mass
(Zwaan et al 1997)
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Limits on I.G. HI Clouds

• Fisher Tully not cosmologically significant
• 1990 Briggs NIGClouds .
• NGalaxies 100
• 2000 Zwaan (PhD Thesis) HI Mass Function
• 2003 Koribalski/Zwaan ET AL HIPASS

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HIPASS Parkes Telescope
Consortium ATNF, Melbourne, Cardiff, RSAA
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Limits on I.G. HI Clouds

• Fisher Tully not cosmologically significant
• 1990 Briggs NIGClouds .
• NGalaxies 100
• 2000 Zwaan (PhD Thesis) HI Mass Function
• 2003 Koribalski/Zwaan ET AL HIPASS
• 1000s of galaxies no I.G. Clouds

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HIPASS result Warren, Jerjen, ET AL . a few
extremely HI rich galaxies
??? I.G. HI Clouds with
stellar contamination ???
B.Warren Theyre galaxies !
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thats the observational evidence.
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Recombination competes with
Re-ionization
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Time scales for Recombination in IGM
t n /R
recomb
e
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Temperature vs Redshift
Tcmb
Tkinetic
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Temperature vs Redshift
first ionizing sources
H
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Temperature vs Redshift
first ionizing sources
H
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Tkinetic
Recombination Time (mean density)
1010yr
109yr
Age of Universe
107yr
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Hydrogen must be confined !
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Sea of ionized baryons
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?? Just HI ??
Stars HI gas
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Barkana Loeb
Dark Matter Halo Mass Function
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Integral Mass Content per logarithmic
interval
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Mass Functions
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Mass Functions
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Mass Functions
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Mass Functions
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Mass Functions
Missing bound baryons
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Fate of baryons in small halos?
Sea of ionized baryons
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Fate of baryons in small halos
Sea of ionized baryons
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• 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 104.3 K
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Conclusions
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NGC 1512 Color coded velocity field
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NGC 3344 HI Gas distribution
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NGC 3344 HI velocity field
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Relative interception cross sections for QSO
Absorption Lines