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Ram Pressure Stripping of Disk Galaxies. Elke Schumacher , Institute of Theoretical Physics und Astrophysics Uni Kiel Gerhard Hensler, Institute for Astronomy Uni Vienna Environments of Galaxies, Crete, August 2004. . Roediger. Analytical Estimate:. Analytical Estimate:.
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Ram Pressure Stripping of Disk Galaxies Elke Schumacher, Institute of Theoretical Physics und Astrophysics Uni Kiel Gerhard Hensler, Institute for Astronomy Uni Vienna Environments of Galaxies, Crete, August 2004 Roediger
Analytical Estimate: 2 dF/dz * Sgas(r) = fgrav= pram = rICMvICM
Analytical Estimate: 2 dF/dz * Sgas(r) = fgrav=pram = rICMvICM
Analytical Estimate: > 2 dF/dz * Sgas(r) = fgrav= pram = rICMvICM <
Analytical Estimate: > 2 dF/dz * Sgas(r) = fgrav= pram = rICMvICM < independent of vertical structure (thickness) ? independent of Mach number?
Scanning the wind parameter space: ICM sound speed ( TICM=4*107K) cluster centres to outskirts
stellar disk mass 8 * 1010 Msun bulge 2 * 1010 Msun gas disk mass 8 * 109 Msun DM mass (R<50kpc) 3.8 * 1011 Msun The model galaxy:
The model galaxy - gas disk: density: 10-3 cm-3= 10-27 g cm-3
The model galaxy - gas disk: same S(r)
Results - time evolution: 2 nICMvICM =1000 cm-3km2 / s2 density: 10-3 cm-3= 10-27 g cm-3
Results - mass and radius of remaining disk: measured: a) mass inside disk region b) bound mass
Results - mass and radius of remaining disk: 2 nICMvICM =1000 cm-3km2 / s2
Results - mass and radius of remaining disk: 2 nICMvICM =1000 cm-3km2 / s2 1Msun / yr
Results - mass and radius of remaining disk: 2 nICMvICM =10 000 cm-3km2 / s2
Results - mass and radius of remaining disk: 2 nICMvICM =100 cm-3km2 / s2
Results - time evolution: 2 nICMvICM =10 cm-3km2 / s2
Results - influence of vertical structure: 2 nICMvICM =1000 cm-3km2 / s2
Results - influence of Mach number: 2 nICMvICM =1000 cm-3km2 / s2
Comparison analytical-numerical: 2 nICMvICM =1000 cm-3km2 / s2
Comparison analytical -numerical a dF/dz * Sgas(r) = fgrav = pram = rICMvICM > < 2
Comparison analytical -numerical adF/dz * Sgas(r) = fgrav = pram = rICMvICM > < 2
Comparison analytical -numerical a dF/dz * Sgas(r) = fgrav = pram = rICMvICM a= 0.25 > < 2
How much gas does fall back? ISM that has left the disk: • 10 to 15% of original gas disk mass
Conclusions: • Stripping radius can be predicted approximately by simple analytical estimate • mainly dependent on ram pressure, slightly on Mach number • independent of vertical structure of gas disk • Cluster centres: heavy truncation and mass loss • displacement of all but inner part in few 10Myr • displaced gas unbound in few 100Myr • Cluster outskirts: nearly no mass loss, yet truncation • displacement of edge in few 100Myr • displaced gas not gas unbound, but falls back
Future Work • basis for further investigations: • inhomogeneous ISM • inclination (other than face-on) • time-dependent wind - cluster crossing
Timescales: 10x
Results - mass and radius of remaining disk: 2 nICMvICM =10 cm-3km2 / s2
Results - location of bound gas: 2 nICMvICM =1000 cm-3km2 / s2