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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. Thanks to my collaborators. Christine Jones William R. Forman Paul Nulsen Ralph Kraft - PowerPoint PPT Presentation
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Probing the Dynamics of Galaxy-Gas Interactions in Groups and Clusters with
Chandra and XMM-Newton
Marie MachacekSmithsonian Astrophysical Observatory
IGM Workshop 3/8/2005
Thanks to my collaborators
Christine Jones
William R. Forman
Paul Nulsen
Ralph Kraft
Alexey Vikhlinin
Maxim Markevitch
Liviu Stirbat
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
NGC 1404 in Fornax
Dosaj et al. 2002 ; Scharf et al. 2004; Machacek et al. 2005
NGC 1399 19 Mpc
Chandra0.3-2 keV134.3 ks
NGC1404
Rp = 54 kpc
Surface Brightness Map
Temperature Map
Tg = 0.55-0.02+0.01 keV
A = 0.7-0.1+0.7 Zs
Model Assumptions
• N1404 & N1399 in same plane
- r ~ rp : stripped tail ICM dense
- sharp edge inclination angle not large
• N1404
- isothermal sphere
- density ng r-
• Surface brightness jump (gng2/cnc
2)
Vikhlinin et al. 2001; Mazzotta et al. 2001
Surface Brightness Profile
1.54
=0.5
re=7.64 kpc0.3, rc=395”
NGC 1404’s Transverse Velocity
Tg/Tc = 0.36ng/nc = 6.0pg/pc = 2.1M1 ~ 1.0v = 657 km/svr = 450 km/s*
vt = 478 km/s ~ 43˚
*Drinkwater et al. 2001
Pressure ratio vs Mach Number
NGC 4552 in Virgo
Chandra54.4 ks0.5-2 keV
Machacek et al. 2005
Surface Brightness Profile
r1 = 1.29 kpc
r2 = 3.12 kpc
=1.29
Surface Brightness Profile
r1 = 1.29 kpc
r2 = 3.12 kpc
T1 = 0.61 keVT2 = 0.44 keVAg = 0.6±0.2 Zs
Tc = 2.2 keV
NGC 4552’s Transverse Velocity
Tg/Tc = 0.2ng/nc = 37 ± 5pg/pc = 7.3 ± 1.1M1= 2.1 ± 0.2v = 1646 km/svr = -968 km/s*
vt = 1331 km/s ~ 36˚ ± 3˚
Pressure ratio vs Mach Number
Tail Properties
• T = 0.57+0.06-0.1 keV
• n ~ 0.006 cm-3 >> nc
• p ~ a few pICM
• length ~ 10 kpc • bowed
Shock Model for Inner Rings
Mach = 1.7 t = 1.32 Myr
Emech = 2.4 1055fv ergs Lmech = 5.8 1041fv ers/s Lmech - Lradio 6.4 1041 ergs/s
Birzan et al. 2004
Tidal InteractionsNGC 6872/ IC 4970
VLT-ANTU+FORS1 ESO Top 20 images
NGC 6872 in PavoD = 53.5 Mpc vr = 849 km/s*
*Martimbeau & Huchra CfA Redshift Survey 2004
Strong Interaction with Pavo XMM pn+mos0.5-2 keV32.2 ks
Machacek et al. 2005 astro-ph 0411286v2
Trail Properties
• Hot T ~1 kev ~2TIGM
• Dense n ~ 1.7nIGM
• Low abundance
A ~ 0.2 ± 0.1 Zs
• Large extent
~ 67 90 kpc
Trail Formation Models• Tidal Stripping - distortions of other tracers ?• Ram Pressure Stripping
- T high? A low? n < 2 nICM
- not like NGC 4552!• Bondi-Hoyle Gravitional Focusing• Turbulent Viscous Stripping
Bondi Gravitational Focusing
Mach ~ 3
/ flat long trail
no large central peak
large gravitating halo ?
vcirc ~ ?
a = 20 kpc ?
sufficient heating ?
Tad ~ 1.4 TIGM
For NFW profile
Turbulent Viscous Stripping
v ~ 1300 km/s ~ 40
Stripping Rate
Energy
Extent +Adiabatic expansion
v = vr / sin
Signatures in the Trail
• Filaments, streamers
gas? stars? dust?• Abundance
galaxy, IGM or mix?• T & n profile
thermalization region?
cools, broadens & dims?
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