Do Galaxy Clusters Boil?

Transcript

1. Do Galaxy Clusters Boil? Mike McCourt & Eliot Quataert February 2014
3. Introduction Intracluster Medium optical xray Fabian et al. (2011)
4. Introduction Intracluster Medium hot gas: T 108 K n 0.03 cm−3 λe ∼ 0.1 kpc rg ∼ 104 km ermal conduction important & anisotropic. xray Fabian et al. (2011)
5. Introduction Physics of Convection Balbus (2000): δz T(z 0 +δz) T(z 0 +δz) < T(z 0 ) T(z 0 ) T(z 0 ); P(z 0 +δz) P(z 0 +δz) P(z 0 ) instability
6. Introduction Physics of Convection Balbus (2000): δz T(z 0 +δz) T(z 0 +δz) < T(z 0 ) T(z 0 ) T(z 0 ); P(z 0 +δz) P(z 0 +δz) P(z 0 ) instability tbuoy ∼ g d ln T dz −1/2 Schwarzchild: δz s(z 0 +δz) s(z 0 +δz) < s(z 0 ) s(z 0 ) s(z 0 ); P(z 0 +δz) P(z 0 +δz) P(z 0 ) instability tbuoy ∼ g ds dz −1/2
7. Introduction Voit et al. (2008) Vikhlinin et al. (2005)
8. Introduction Magnetothermal Instability (linear) Temperature (t = ) Temperature (t =  tbuoy )
9. Introduction Magnetothermal Instability (non-linear) t = 0 t = 4 tbuoy t = 6 tbuoy t = 10 tbuoy t = 30 tbuoy
10. Temperature Profiles in Clusters Motivation 0.2 10 9 8 7 0.0 0.4 r (Mpc) T (keV) 0.6 0.8 1.0 Initial 1 1.5 2.5 3.5 Parrish et al. (2008) Simionescu et al. (2011)
11. “Semi-Cosmological” Simulations Setup z = 0.7 z = 0.3 z = 0.0
12. “Semi-Cosmological” Simulations Movie (N.B. this is a link in the pdf. will convert presentation to keynote and stick the movie in the file.) temperature temperature perturbation
15. “Semi-Cosmological” Simulations Strength of the convection? r / r200 Turbulent Mach # 0.0 0.5 1.0 1.5 0.1 0.2 0.3 0.4 1014M 1015M 3 × 1015M r / r200 (δT)(δvr)/c3 s 0.0 0.5 1.0 1.5 10−4 10−3 10−2 10−1
16. Magnetic Field Amplification 1014 Msun 3×1014 Msun 1015 Msun
17. Conclusion Do Galaxy Clusters Boil? t = 0 t = 4 tbuoy t = 6 tbuoy t = 10 tbuoy t = 30 tbuoy 0.2 10 9 8 7 0.0 0.4 r (Mpc) T (keV) 0.6 0.8 1.0 Initial 1 1.5 2.5 3.5
18. Backup Slides
19. Bremsstrahlung Signature 1014 Msun 1.5% 1015 Msun 10% 3×1014 Msun 1.5% 3×1015 Msun 25%
20. Particle Mean Free Path Spitzer-Härm collisionless q0 Bale et al.  Derived from the  electron distribution function measured with the NASA Wind spacecraft.
21. Temperature Profiles in Clusters Accretion Histories 1 + z M(z) / M(z = 0) 1 2 3 4 0.2 0.4 0.6 0.8 1.0 Type 0 Type I Type II Type III McBride et al. 2009: M(z) ∝ [(1 + z)b exp(−z)]g
22. “Semi-Cosmological” Simulations cf.  Models Type 0 r / r200 K 10−2 10−1 1 10−2 10−1 1 Type I r / r200 10−2 10−1 1 Type III r / r200 10−2 10−1 1 r / r200 T 0.0 0.5 1.0 1.5 0.5 1.0 1.5 2.0 2.5 3.0 r / r200 0.0 0.5 1.0 1.5 r / r200 0.0 0.5 1.0 1.5 2.0
24. What determines the temperature of the gas at large radii in clusters?
25. Temperature Profiles in Clusters Entropy Generation at the Virial Shock gas shocks rvir rshock rshell
26. Temperature Profiles in Clusters Adiabatic Evolution r/rsh T/Tvir slow accretors: ˙ M M /t dyn fast accretors: ˙ M ∼ M/tdyn slow accretors: ˙ M M /t dyn fast accretors: ˙ M ∼ M/tdyn slow accretors: ˙ M M /t dyn fast accretors: ˙ M ∼ M/tdyn slow accretors: ˙ M M /t dyn fast accretors: ˙ M ∼ M/tdyn slow accretors: ˙ M M /t dyn fast accretors: ˙ M ∼ M/tdyn slow accretors: ˙ M M /t dyn fast accretors: ˙ M ∼ M/tdyn slow accretors: ˙ M M /t dyn fast accretors: ˙ M ∼ M/tdyn slow accretors: ˙ M M /t dyn fast accretors: ˙ M ∼ M/tdyn slow accretors: ˙ M M /t dyn fast accretors: ˙ M ∼ M/tdyn slow accretors: ˙ M M /t dyn fast accretors: ˙ M ∼ M/tdyn slow accretors: ˙ M M /t dyn fast accretors: ˙ M ∼ M/tdyn slow accretors: ˙ M M /t dyn fast accretors: ˙ M ∼ M/tdyn 0.0 0.2 0.4 0.6 0.8 1.0 0.2 0.4 0.6 0.8 1.0 1.2 1.4 In the case of an Isothermal Potential, this is a simple problem. T(0) = Tvir T(out) = Tsh Temperature Gradient set by Accretion Rate (tdyn × d ln M/dt)
27. Temperature Profiles in Clusters r/rvir 0.0 0.25 0.5 0.75 1014M r/rvir 0.0 0.25 0.5 0.75 1.0 1015M r/rvir T/Tvir 0.0 0.25 0.5 0.75 0.5 1.0 1.5 1014.5M Accretion histories from McBride et al. 2009
28. Simulating convection in a forming cluster.
29. “Semi-Cosmological” Simulations Anisotropic vs. Isotropic Conduction Increasing Mass + Conductivity Isotropic
30. “Semi-Cosmological” Simulations Anisotropic vs. Isotropic Conduction Increasing Mass + Conductivity Anisotropic Isotropic