Physics and fate of jet related emission line regions

1
Physics and fate of jet related emission line
regions

• Martin Krause
• Volcano - 20th May 2008
• Paul Alexander, David Heath, Martin
  Huarte-espinosa, Nicole Nesvadba, Volker gaibler,
  Max Camenzind

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Overview

• Introduction Jet related emission line regions
• 3D Multiphase turbulence simulations
• Long term evolution May jets distribute the
  metals in clusters?

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Emission Line Regions in Extragalactic Jet Flows

• High redshift radio galaxies
• Historically often RG most distant objects
• From zgt1/2 extended (lt100 kpc)narrow emission
  line regions (ENLR)
• ENLR Aligned with radio Alignment effect
• Jet induced star formation? Little evidence
  (spectral stellar features)

Redshift 1 radio galaxies
blue radio cons
red radio cons
Linear scale, 50 kpc
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Emission Line Regions in Extragalactic Jet Flows
High redshift radio galaxies
Redshift 1 radio galaxies
blue radio cons
red radio cons
Linear scale, 50 kpc
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Emission Line Regions in Extragalactic Jet Flows
0406-242 z2.4, OIII, Hß, gt1010 M?, v1000
km/s (Nesvadba et al. 2008, prep.)
3C305 Nearby, Ha, HI absorption, 106 M?,
v1000 km/s (Morganti 2007)
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Emission Line Regions in Extragalactic Jet Flows

• Giant Lyman alpha haloes
• Strongest line at high z
• up to z gt 5
• Aligned X-ray IC, highlights cocoon of faint,
  backflowing radio plasma
• Morphology suggest ENLR cocoon

4C 41.17, z3.8 (Michiel Reuland) Blue Lymana,
Green radio, Red X-ray
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Jet Interaction Model
Krause (2005), 3D bipolar jet simulation
Shocked ambient gas (red)
Hotspot
Beams (pink / green)
Origin of two jets
Cocoon (blue, back- flowing jet plasma)
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Jet Interaction Model
Simulation (2.5D) of an FR I jet
Krause (2005), 3D bipolar jet simulation
Shocked ambient gas (red)
Hotspot
Beams (pink / green)
Origin of two jets
Cocoon (blue, back- flowing jet plasma)
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Extended Emission line Regions Observational
Summary

• Size up to 100 kpc anticorrelated w. radio size
• EL-power ? Radio power
• Line width 500-1000 km/s ? (radio size)-1
• bulk flow few 100 km / s
• Volume 103-4 kpc3
• EL-power density
  1041 erg/s/kpc3
• EL-Temperature 104 K
• EL-Density 102-103 cm-3
• EL-Mass density 107
  M?/kpc3 entrained gas mass
• EL-gas filling factor 10-4-10-3 (poorly
  constrained)

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Cocoon or Shocked Ambient Where is the
emission line gas?
Cocoon co-spatial with radio or in between
lobes, filled Shocked ambient hollow shell
surrounding radio, like X-ray cavieties
0316-257, z3.3 (Nicole Nesvadba)
-gt Morphology suggests Cocoon
2.5D-Sim. EL-gas radio contours Gaibler et al.
in prep.
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Simulation jet with cooling
(smooth back- ground)
Density
Temperature
1 Myr
Before cooling some mixing in the central regions
3 Myr

• Most EL power ( jet power) from shell, profile
  rarely observed

Immediately after cooling Thin Shell has formed.
7 Myr
Long after cooling Shell fragments, cool clouds,
SF

• Need very high resolution to see cool clouds in
  cocoon at all gtgt reality more coc. cl.

• If we start with smooth background, we always get
  a shell structure (from cooled amient)

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The three gas phases in radio galaxies
Cygnus A X-ray radio contours (z0, courtesy
C. Carilli, P. Strub)
3C 368 Optical radio contours (z1, Best et
al. 1996)
Phase 1 radio hot, Tgt1011K always
detected Phase 2 X-ray warm,
107KltTlt108K low-z, few high-z detections Phase
3 opt. etc.cold, Tlt105K becomes
prominent for zgt0.6 alignment
effect
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Multiphase turbulence in radio cocoons ?
Simulations

• Setup
• Start with Kelvin-Helmholtz instability plus
  dense clouds
• Compressible 2D 3D hydrodynamics cooling,
  codes Nirvana, Flash
• Density ratios 10-4, Mach 0.8 (80 in warm
  medium)
• Here vary warm gas Temperature and cloud
  density, ctrl no clouds

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Multiphase turbulence in radio cocoons ? 3D
Results
Emissivity
Vertical Integral
Horizontal Integral
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Multiphase turbulence in radio cocoons ? 3D
Results
Slices of log. density

• Cool gas tends to form small cloudlets
• clouds shielded by intermediate material
• 2D filaments

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Data Analysis Kinematics
2D
Slow cooling M const
Rapid cooling M ?1/2

• Same in 2D 3D
• hot subsonic, cold supersonic
• mixing faster in 3D, res lower
• can compute EL-gas velocities from env. jet
  parameters (ok)

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Data Analysis Energy 3D

• Results Readjustment 2Myrs, ctrl then conserved
• Energy drops due to clouds
• Energy drops faster with higher cloud mass

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Numerical issues

• No natural heat conduction (so far) gt too little
  heat transfer to cold clouds, evaporation? No!
  (gtunresolved scales)
• Artificial numerical heat conduction. Is cooling
  dominated by smeared out contact surface? No -
  next slide. Expect correlation of EL-power with
  kinetic energy for shock transport (what we want
  to see), or warm gas temp., respectively

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Data Analysis EL-pow - Ekin
Both correlations seen Best one with kinetic
energy gt We simulate a realisation of the shock
ionisation scenario
startup mess
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Data Analysis EL-pow - Ekin
Etot correlates with cloud density gt increased
pressure compresses clouds n Etot too small
wrt obs.
high n also contributes to Etot - EL-pow
correlation gt little effect of art. heat
conduction
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Data Analysis Temperature Distribution
14,000 K

• Realisation of shock ionisation scenario
  equilibrium temperature 14,000 K independent of
  simulation details
• Mixing different in 2D and 3D (also resolution
• Signal above mixing level evident in both cases
• Evidence for cooler gas (1000 K, molecular?)

2D
3D
14,000 K
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Data Analysis Elgas dens. - Temp
Observations
Temperature ok n too low -gt Total energy in box
too small
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Data Analysis EL-pow - vel.
Observations

• dominated by time evolution
• no obvious correlation
• but some dependence on amb. temperature, more dv
  gt tot. Ener. matters

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Data Analysis Eelgasfrac - Time

• 2D suggested that 10 up to nearly all energy in
  cold gas
• 3D small fraction, 0.1 - 1
• unfortunately 3D not converged res x 2 gt
  Ecoldfrac x 3

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Data Analysis Tcool,dyn - Etot
Observations Tcool,dyn 70 Myr This is
reasonable, if Elgas to be obs. Would get this
for Eelgas Etot
Observations
Would hires 3D models get us back to Eelgas
Etot ?
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Data Analysis Mcoldfrac-Time

• 2D very fast growth
• 3D res x 2 gt loss -gt growth
• not enough res yet to start at low cold mass
  fraction

3D
2D

• same start cold frac, same res low T_amb
  increase, high T_amb decrease
• Obs low redshift RG higher T_amb gt no Elgas

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Summary - 3d multiphase turbulence

• ELgas (often) in cocoon
• Presented 3D sims of multiphase turbulence in
  jet cocoons, varied res., amb. Temp. and init.
  cold gas fraction
• Presented statistics of intensive
  (n,T,dv,Ecoldfrac, Mcoldfrac) and extensive
  (Etot, Mcold, EL-power) variables
• Honest try, but res. problems, wrong par. regime

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Summary - 3d multiphase turbulence

• We do find
• Equilibrium T 14,000 K
• Etot decreases i.e. MPT-enhanced system cooling
• Mcold increases i.e. MPT-enhanced condensation,
  more for low amb. temp., meaning
• Much of EL-gas could be cooled IGM gas rather
  than wrapped up galactic gas
• Higher amb. temp. at low z, gtgt no EL-gas
• Correlations (P_elgas-E_kin, dv- E_tot) argue
  not dom. by num. effects

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Enrichment of galaxy clusters - may jets do the
job?
Abundance in Perseus Sanders et al. 2005
Perseus cluster core Chandra homepage

• Gas in galaxy clusters is highly enriched.
• Jets upset gas when active - but what happens in
  the long run?
• Jets set up large scale flows for long times.
• Can jets contribute to the metal distribution?

Basson Alexander 2003 rad. Velocity _at_ 0.4,
0.5 1.9 Gyr
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Mpc-scale simulation with tracer particles

• Advected in shocked ambient gas entrained into
  cocoon during active phase
• Rises with jet remnant up to Mpc scale

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Resulting metallicity Distribution

• After 3 Gyr, flat distribution
• up to Mpc scale
• about 1/10th initial core metallicity
• works with powerful jets only
• i.e. at redshift gt 1

• works with powerful jets only
• i.e. at redshift gt 1
• all consistent with observations

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Summary Cluster Metal enrichment

• Powerful jets (high z) may do the job
• Reach roughly flat profile
• Need long timescales, Gyr