1. Probing the Dynamics of Galaxy-Gas Interactions in Groups and Clusters with Chandra and XMM-Newton Marie Machacek Smithsonian Astrophysical Observatory IGM Workshop 3/8/2005

2. Thanks to my collaborators Christine Jones William R. Forman Paul Nulsen Ralph Kraft Alexey Vikhlinin Maxim Markevitch Liviu Stirbat

3. Galaxy-IGM Interactions in Three Systems Elliptical NGC 1404 Fornax Cluster kT = 1.5 keV Transonic ram-pressure stripping Elliptical NGC 4552 Virgo Cluster kT = 2.2 keV Supersonic ram-pressure stripping Spiral NGC 6872 Pavo Group kT = 0.5 keV High velocity encounter

4. NGC 1404 in Fornax Dosaj et al. 2002 ; Scharf et al. 2004; Machacek et al. 2005 NGC 1399 19 Mpc Chandra 0.3-2 keV 134.3 ks NGC1404 R p = 54 kpc

5. Surface Brightness Map Temperature Map T g = 0.55 -0.02 +0.01 keV A = 0.7 -0.1 +0.7 Z s

6. Model Assumptions N1404 & N1399 in same plane - r ~ r p : stripped tail  ICM dense - sharp edge  inclination angle  not large N1404 - isothermal sphere - density n g  r -  Surface brightness jump  (  g n g 2 /  c n c 2 ) Vikhlinin et al. 2001; Mazzotta et al. 2001

7. Surface Brightness Profile  1.54  =0.5 r e =7.64 kpc  0.3, r c =395”

8. NGC 1404’s Transverse Velocity T g /T c = 0.36 n g /n c = 6.0 p g /p c = 2.1 M 1 ~ 1.0 v = 657 km/s v r = 450 km/s * v t = 478 km/s  ~ 43˚ *Drinkwater et al. 2001 Pressure ratio vs Mach Number

9. NGC 4552 in Virgo Chandra 54.4 ks 0.5-2 keV Machacek et al. 2005

11. Surface Brightness Profile r 1 = 1.29 kpc r 2 = 3.12 kpc  =1.29

12. Surface Brightness Profile r 1 = 1.29 kpc r 2 = 3.12 kpc T 1 = 0.61 keV T 2 = 0.44 keV A g = 0.6±0.2 Z s T c = 2.2 keV

13. NGC 4552’s Transverse Velocity T g /T c = 0.2 n g /n c = 37 ± 5 p g /p c = 7.3 ± 1.1 M 1 = 2.1 ± 0.2 v = 1646 km/s v r = -968 km/s * v t = 1331 km/s  ~ 36˚ ± 3˚ Pressure ratio vs Mach Number

14. Tail Properties T = 0.57 +0.06 -0.1 keV n ~ 0.006 cm -3 >> n c p ~ a few  p ICM length ~ 10 kpc bowed

15. Shock Model for Inner Rings  Mach = 1.7 t = 1.32 Myr E mech = 2.4  10 55 f v ergs L mech = 5.8  10 41 f v ers/s L mech - L radio  6.4  10 41 ergs/s Birzan et al. 2004

16. Tidal Interactions NGC 6872/ IC 4970 VLT-ANTU+FORS1 ESO Top 20 images

17. NGC 6872 in Pavo D = 53.5 Mpc  v r = 849 km/s * *Martimbeau & Huchra CfA Redshift Survey 2004

18. Strong Interaction with Pavo XMM pn+mos 0.5-2 keV 32.2 ks Machacek et al. 2005 astro-ph 0411286v2

19. Trail Properties Hot T ~1 kev ~2T IGM Dense n ~ 1.7n IGM Low abundance A ~ 0.2 ± 0.1 Z s Large extent ~ 67  90 kpc

20. Trail Formation Models Tidal Stripping - distortions of other tracers ? Ram Pressure Stripping - T high? A low? n < 2 n ICM - not like NGC 4552! Bondi-Hoyle Gravitional Focusing Turbulent Viscous Stripping

21. Bondi Gravitational Focusing Mach ~ 3  /  flat  long trail no large central peak large gravitating halo ? v circ ~ ? a = 20 kpc ? sufficient heating ? T ad ~ 1.4 T IGM For NFW profile

22. Turbulent Viscous Stripping v ~ 1300 km/s  ~ 40    Stripping Rate Energy Extent + Adiabatic expansion v = v r / sin 

23. Signatures in the Trail Filaments, streamers gas? stars? dust? Abundance galaxy, IGM or mix? T & n profile thermalization region? cools, broadens & dims?

24. Conclusions Constrain 3-D motion of galaxy Show stripping processes in action Reveal interactions previously overlooked Differentiate between different stripping processes X-ray Observations of Edges, Tails and Trails