Is this a bit better

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Pollution of the IGM and Mechanical Feedback
Evan Scannapieco Kavli Institute of Theoretical
Physics UC Santa Barbara
Collaborators Andrea Ferrara, Piero Madau, Rob
Thacker, Marc Davis, Patrick Petitjean,
Jacqueline Bergeron
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Missing Satellites
Photo- Evaporation
environmental
local
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Dogma 1 Blow out and Blow Away
MacLow Ferrara 1999 Ferrara Tolstoy 2000
L38 ? L/1038 erg s-1 ? 3 SNe/Myr


For high SFRs and M lt 108 M?, you can eject a
significant fraction of the ICM Up to 1011 M?,
You eject a significant fraction of metals
and energy
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Dogma 2 Outflowing Hot Gas
Hot gas escaping from lt 150 km/s galaxies
Martin (2004)
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Two Scenarios
Mechanical Evaporation
Cooling
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Baryonic Stripping

Empty Dark Matter Halo Left Behind Dominant
mechanism
(Scannapieco, Ferrara, Broadhurst 2000)
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Numerical Study of Outflows (ES, Thacker, Davis
2001 Thacker, ES, Davis 2002)

• SPH code-Hydra
• 8 Mpc3 Box 2 x 1923 particles 2.5x106
• 2 runs, one with star formation only, with f
  0.1 in each galaxy forming stars.
• The second run included outflows, as shells
  around galaxies
• Ran to z4

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Why does it look like this?
ES (2005)
1.) Efficiency of ejection ESN ???stars?? EPE
?????R???????
2.) More numerous R ? (E ?-1)1/5 r ? (1z)2/5
E1/5
V x n ? (1z)6/5 E3/5 /M
3.) Early Forming
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Dwarf Galaxy Suppression
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Outflows
No outflows
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Can we constrain this process directly?
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Yes!
ES, Aracil, Petitjean, Pichon, Thacker, Pogosyan,
Couchman, Bergeron (2006)
ESO-LP Cosmic Evolution of the IGM
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CIV Correlation Function
?(z)1

• Very High Bias
• Two-slope shape with a knee at 150 km/s

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Constant Z
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Bubble Modeling
Paint Spheres of metals --- with a fixed radius
Rs about z3 groups of --- a fixed mass M
Tracer of CLUSTERING
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Bubble Model
FF 15
M108 M?, z 8
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Conclusions
Outflows impact dwarf galaxy formation primarily
by slowing accretion and stripping gas from
neighboring previrialized perturbations. Dwarves
dominate IGM pollution due somewhat to small
potentials, but mostly because of large numbers,
and early formation times. Distribution of IGM
metals consistent with fiducial picture of
enrichment from high-z dwarves
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Analytical Estimate
CDM
Compare Ts with Tvir at mean separation
tcool gt tsound crossing k Ts / ne L gt l/ cs
LCDM
f Ms vs gt Mc vc
Tvir105 K, vcirc 60 km/s
(Scannapieco, Ferrara, Broadhurst 2000)
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Outflows A simple analytic model
ES, A. Ferrara, P. Madau (2002)

• 12 Mpc3 Box, in which we tagged the positions of
  forming galaxies from 3x107--1012 (3D Press
  Schecter type approach)
• We take a fraction f 0.01,.1,.5 of baryons to
  form stars, 1 SN per 138 solar masses of stars.
• 10 of the energy goes into the outflow
• Outflows are modeled as thin spherical shells
• Host galaxy remains intact
• Ejected mass Mass in stars
• Ejected metals 1/2 of the total

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Parameter Study Filling Factor
ES, A. Ferrara, P. Madau (2002)

• Incomplete transition for all f values.
• Strong dependence on lower limit
• FF is mostly in place by z8 or so

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Distribution of Metals and IGM Evolution
d? 20, environments similar evolution for all
models similar values for f 0.1
LogZ/Z -3,-2,-1,0
A. Songaila 2001, Pettini etal 2003 compared
with ES, A. Ferrara, P. Madau 2002
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Parameter Study Filling Factor vs Dwarf Galaxy
Suppression
ES, A. Ferrara, P. Madau (2002)

• Close relation between stripping and IGM ff.

Suppression Factor
fm 1.0,0.5,0.25
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Filling Factor vs Dwarf Galaxy Suppression
ES, A. Ferrara, P. Madau (2002)
f 0.5,0.1,0.01

• Suppressed galaxy masses 3x108--1010
• At fixed mass loading (50) similar relation
  between stripping and IGM ff.
• Increasing mass loading increases stripping (more
  momentum at fixed energy input)

fm 1.0,0.5,0.25
fm 2.0,1.0,0.5
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Mechanical Feedback Shock-stripping
Sigward, Ferrara ES 2005
M109 Mo
z 9
t 0 - 200 Myr
NFW density profile
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Mechanical Feedback Shock-stripping
Sigward, Ferrara ES 2005