Ram pressure stripping of disk galaxies along cluster orbits

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Ram pressure stripping of disk galaxies along
cluster orbits
Elke Roediger, Marcus Brüggen
BREMEN
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Caught in the act
R-band
HI contours
NGC 4522 Kenney et al. 2004
NGC 4402 Crowl et al. 2005
R-band
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Caught in the act
120kpc
NGC 4388 Oosterloo van Gorkom 2005
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Caught in the act
Chung et al. 2007
10kpc
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Caught in the act
Long tails at distances of 0.6 to 1 Mpc from
cluster centre!
Chung et al. 2007
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Simulations so far constant ICM wind ? wind
tunnel
Hydro e.g. Abadi et al. 1999 (SPH) Quilis et al.
2000 (grid) Schulz Struck 2001 (SPH) Marcolini
et al. 2003 (grid) Roediger Hensler 2005
(grid,2D) Roediger Brüggen 2006 (grid) Roediger
et al. 2006 (grid)

• Simple analytical estimate works if galaxy not
  near edge-on
• Time delay in unbinding gas from galactic
  potential

Variable ram pressure in sticky
particles Vollmer et al. 2000, 2001a/b, 2003,
, 2007
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Setup Cluster

• r b-profile, Tconst.,
• static F such that hydrostatic equilibrium
• Two clusters compact (Virgo), extendend (Coma)

2 Mpc
4 Mpc
2 Mpc
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Setup Cluster

• r b-profile, Tconst.,
• static F such that hydrostatic equilibrium
• Two clusters compact (Virgo), extendend (Coma)

2 Mpc
4 Mpc
2 Mpc
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SetupGalaxy

• Static analytic F for DM-halo, stellar disk,
  bulge
• vrot200km/s
• Gas disk in hydrostatic equilibrium

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Setup Orbits

• bound, first infall
• Short/long and medium/high ram pressure peaks

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Numerics

• FLASH code
• 3D
• Adaptive Mesh Refinement (AMR)
• just hydrodynamics

1 block 83 cells
1Mpc
Dx63kpc
Dx0.5kpc (0.25kpc)
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Results
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Results analytical vs numerical
Radius
Mass
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Results stripped gas in the ICM
ISM density
ISM density
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Results wakes
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Results wakes
40kpc
40kpc
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Caught in the act
Chung et al. 2007
10kpc
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Results wakes
along major axes
along tail
Position-Velocity diagramms Chung et al. 2007
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Results wakes
along major axes
along tail
Position-Velocity diagramms Chung et al. 2007
Small velocity width in tail
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Results wakes
Perpendicular to orbit
Along orbit
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Also critical
NGC 4388 Oosterloo van Gorkom 2005
120kpc
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Caught in the act?
NGC 4388 Oosterloo van Gorkom 2005
500km/s
120kpc
Radial velocity w.r.t. Virgo cluster is 1400km/s
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Caught in the act?
NGC 4388 Oosterloo van Gorkom 2005
500km/s
120kpc
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Summary

• Analytical estimate (GunnGott) often not bad but
  fails if
• galaxy moves near edge-on
• significant continuous stripping
• Reproduce long tails at large clustercentric
  distances, but difficulties with velocity
  structure
• Individual candidates have to be checked
  carefully