Simulations of the merging galaxy cluster Abell 3376
Rubens Machado, IAG/USP Gastão Lima Neto, IAG/USP
USP Conference: Cosmology, Large Scale Structure and First Objects, 05/02/2013 Summary
Rubens Machado (IAG/USP) Simulations of the merging galaxy cluster Abell 3376 2 / 30 Cluster mergers
14 Mvir ∼ 10 M
Rvir ∼ 1 Mpc
b ∼ 100 kpc v ∼ 1000 km/s ∆t ∼ 1 Gyr
Mach ∼ 1 − 3 Cluster mergers are the mechanisms 63 by which clusters assemble Egrav ∼ 10 erg
Rubens Machado (IAG/USP) Simulations of the merging galaxy cluster Abell 3376 3 / 30 Simulations of cluster mergers: examples
transient structures, Poole et al. (2006)
Rubens Machado (IAG/USP) Simulations of the merging galaxy cluster Abell 3376 4 / 30 Simulations of cluster mergers: examples
gas sloshing and cold fronts Ascasibar & Markevitch (2006)
Rubens Machado (IAG/USP) Simulations of the merging galaxy cluster Abell 3376 4 / 30 Simulations of cluster mergers: examples
gas sloshing and cooling flows, ZuHone et al. (2010)
Rubens Machado (IAG/USP) Simulations of the merging galaxy cluster Abell 3376 4 / 30 Simulations of cluster mergers: examples
parameter space exploration of mergers to study entropy ZuHone (2011)
Rubens Machado (IAG/USP) Simulations of the merging galaxy cluster Abell 3376 4 / 30 Simulations of cluster mergers: examples
radio relics, van Weeren et al. (2011)
Rubens Machado (IAG/USP) Simulations of the merging galaxy cluster Abell 3376 4 / 30 Simulations of cluster mergers: examples
triple merger, Brüggen et al. (2012)
Rubens Machado (IAG/USP) Simulations of the merging galaxy cluster Abell 3376 4 / 30 Simulations of cluster mergers: examples
the Bullet Cluster: Springel & Farrar (2007), Mastropietro & Burkert (2007) Takizawa (2005, 2006), Milosavljevic´ et al. (2007)
Rubens Machado (IAG/USP) Simulations of the merging galaxy cluster Abell 3376 4 / 30 Cluster mergers
1) 1E 0657-56 (Clowe et al. 2006), “Bullet Cluster” clusters in which gas 2) MACS J0025.4-1222 (Bradac et al. 2008) 3) Abell 520 (Mahdavi et al. 2007), “Train Wreck” has become dissociated 4) Abell 2744 (Merten et al. 2011), “Pandora’s Cluster” 5) Abell 2163 (Okabe et al. 2011) from dark matter 6) Abell 1758 (Ragozzine et al. 2011) 7) DLSCL J0916.2+2951 (Dawson 2012), “Musket Ball Cluster”
Rubens Machado (IAG/USP) Simulations of the merging galaxy cluster Abell 3376 5 / 30 Abell 3376
14 Mvir = 5.2 × 10 M z = 0.0456
Rubens Machado (IAG/USP) Simulations of the merging galaxy cluster Abell 3376 6 / 30 radio relics
ROSAT (X-ray) + VLA (radio) Bagchi, Durret, Lima Neto & Paul (2006)
Abell 3376: a nearby merging cluster
X-ray emission
XMM-Newton
Rubens Machado (IAG/USP) Simulations of the merging galaxy cluster Abell 3376 7 / 30 Abell 3376: a nearby merging cluster
X-ray emission radio relics
XMM-Newton ROSAT (X-ray) + VLA (radio) Bagchi, Durret, Lima Neto & Paul (2006)
Rubens Machado (IAG/USP) Simulations of the merging galaxy cluster Abell 3376 7 / 30 Abell 3376: a nearby merging cluster
X-ray emission radio relics
XMM-Newton ROSAT (X-ray) + VLA (radio) Bagchi, Durret, Lima Neto & Paul (2006)
Rubens Machado (IAG/USP) Simulations of the merging galaxy cluster Abell 3376 7 / 30 Abell 3376: radio
giant (2 Mpc) radio lobes around cluster no associated jets magnetic field ∼ 1µG
Rubens Machado (IAG/USP) Simulations of the merging galaxy cluster Abell 3376 8 / 30 Abell 3376: brightest cluster galaxies
optical (galaxies)
Rubens Machado (IAG/USP) Simulations of the merging galaxy cluster Abell 3376 9 / 30 Abell 3376: brightest cluster galaxies
optical (galaxies)
Rubens Machado (IAG/USP) Simulations of the merging galaxy cluster Abell 3376 9 / 30 Abell 3376: brightest cluster galaxies
X-ray (intracluster gas)
second BCG coincides with X-ray peak; BCG does not
Rubens Machado (IAG/USP) Simulations of the merging galaxy cluster Abell 3376 9 / 30 Abell 3376: brightest cluster galaxies
X-ray (intracluster gas)
second BCG coincides with X-ray peak; BCG does not separation: 970 kpc
Rubens Machado (IAG/USP) Simulations of the merging galaxy cluster Abell 3376 9 / 30 initial parameters: • DM density profile • mass ratio • gas density profile • gas fraction • initial relative velocity • impact parameter
Numerical simulations: initial conditions
Rubens Machado (IAG/USP) Simulations of the merging galaxy cluster Abell 3376 10 / 30 initial parameters: • DM density profile • mass ratio • gas density profile • gas fraction • initial relative velocity • impact parameter
Numerical simulations: initial conditions
Rubens Machado (IAG/USP) Simulations of the merging galaxy cluster Abell 3376 10 / 30 Numerical simulations: initial conditions
initial parameters: • DM density profile • mass ratio • gas density profile • gas fraction • initial relative velocity • impact parameter
Rubens Machado (IAG/USP) Simulations of the merging galaxy cluster Abell 3376 10 / 30 Numerical simulations: initial conditions
initial parameters: a posteriori: • DM density profile • mass ratio • time after central passage • gas density profile • gas fraction • projection angles • initial relative velocity • impact parameter
Rubens Machado (IAG/USP) Simulations of the merging galaxy cluster Abell 3376 10 / 30 Numerical simulations: alphacrucis, 2304 cores
Rubens Machado (IAG/USP) Simulations of the merging galaxy cluster Abell 3376 11 / 30 Numerical simulations: evolution
X-ray surface brightness
emission-weighted temperature
time
Rubens Machado (IAG/USP) Simulations of the merging galaxy cluster Abell 3376 12 / 30 Numerical simulations: evolution
Rubens Machado (IAG/USP) Simulations of the merging galaxy cluster Abell 3376 13 / 30 Numerical simulations: parameter space sample
Rubens Machado (IAG/USP) Simulations of the merging galaxy cluster Abell 3376 14 / 30 : Hernquist (similar to NFW) : Dehnen γ=0 (similar to β-model)
: fgas = 0.18
Numerical simulations: parameter space of IC
initial parameters: • DM density profile • gas density profile • initial relative velocity • mass ratio • gas fraction • impact parameter
Rubens Machado (IAG/USP) Simulations of the merging galaxy cluster Abell 3376 15 / 30 : Dehnen γ=0 (similar to β-model)
: fgas = 0.18
Numerical simulations: parameter space of IC
initial parameters: • DM density profile : Hernquist (similar to NFW) • gas density profile • initial relative velocity • mass ratio • gas fraction • impact parameter
Rubens Machado (IAG/USP) Simulations of the merging galaxy cluster Abell 3376 15 / 30 : fgas = 0.18
Numerical simulations: parameter space of IC
initial parameters: • DM density profile : Hernquist (similar to NFW) • gas density profile : Dehnen γ=0 (similar to β-model) • initial relative velocity • mass ratio • gas fraction • impact parameter
Rubens Machado (IAG/USP) Simulations of the merging galaxy cluster Abell 3376 15 / 30 Numerical simulations: parameter space of IC
initial parameters: • DM density profile : Hernquist (similar to NFW) • gas density profile : Dehnen γ=0 (similar to β-model) • initial relative velocity • mass ratio • gas fraction : fgas = 0.18 • impact parameter
Rubens Machado (IAG/USP) Simulations of the merging galaxy cluster Abell 3376 15 / 30 Numerical simulations: parameter space of IC
initial parameters: • DM density profile : Hernquist (similar to NFW) • gas density profile : Dehnen γ=0 (similar to β-model) • initial relative velocity • mass ratio • gas fraction : fgas = 0.18 • impact parameter • temperature profile : from hydrostatic equilibrium
Rubens Machado (IAG/USP) Simulations of the merging galaxy cluster Abell 3376 15 / 30 Numerical simulations: parameter space of IC
initial parameters: • DM density profile : Hernquist (similar to NFW) • gas density profile : Dehnen γ=0 (similar to β-model) • initial relative velocity • mass ratio • gas fraction : fgas = 0.18 • impact parameter • temperature profile : from hydrostatic equilibrium
Rubens Machado (IAG/USP) Simulations of the merging galaxy cluster Abell 3376 15 / 30 Numerical simulations: mass ratio
MB = 1/2 1/4 1/6 1/8 MA
Rubens Machado (IAG/USP) Simulations of the merging galaxy cluster Abell 3376 16 / 30 Numerical simulations: impact parameter
b = 0 150 kpc 350 kpc 500 kpc
Rubens Machado (IAG/USP) Simulations of the merging galaxy cluster Abell 3376 17 / 30 Numerical simulations: initial relative velocity
vo = 500 km/s 1000 km/s 1500 km/s 2000 km/s
Rubens Machado (IAG/USP) Simulations of the merging galaxy cluster Abell 3376 18 / 30 Numerical simulations: relative gas concentration
• central gas density of the minor cluster
ρB = 1 2 4 6 ρA
Rubens Machado (IAG/USP) Simulations of the merging galaxy cluster Abell 3376 19 / 30 Numerical simulations: inclination
i = 0◦ 30◦ 40◦ 60◦
Rubens Machado (IAG/USP) Simulations of the merging galaxy cluster Abell 3376 20 / 30 Comparison to observations
observed simulated
Rubens Machado (IAG/USP) Simulations of the merging galaxy cluster Abell 3376 21 / 30 Mach number
Rubens Machado (IAG/USP) Simulations of the merging galaxy cluster Abell 3376 22 / 30 Mach number: Rankine-Hugoniot jump conditions
emission map
temperature map
T 5M4 + 14M2 − 3 2 = T 16M2 temperature 1 n 4M2 2 = 2 density n1 M + 3
P 5M2 − 1 2 = pressure P1 4 ! !−5/3 S 5M2 − 1 4M2 2 = 2 entropy S1 4 M + 3
2 ! 3M − 3 vx,2 − vx,1 = (vs − u) streaming 4M2 gas velocity
Rubens Machado (IAG/USP) Simulations of the merging galaxy cluster Abell 3376 23 / 30 i = 40◦
M = 2.9
Mach number: inclination
i = 0◦
M = 3.9
Rubens Machado (IAG/USP) Simulations of the merging galaxy cluster Abell 3376 24 / 30 Mach number: inclination
i = 0◦ i = 40◦
M = 3.9 M = 2.9
Rubens Machado (IAG/USP) Simulations of the merging galaxy cluster Abell 3376 24 / 30 Dark matter
How is the dark matter distributed?
Rubens Machado (IAG/USP) Simulations of the merging galaxy cluster Abell 3376 25 / 30 Dark matter
projected mass (total)
Rubens Machado (IAG/USP) Simulations of the merging galaxy cluster Abell 3376 26 / 30 BCG separation and dark matter
Rubens Machado (IAG/USP) Simulations of the merging galaxy cluster Abell 3376 27 / 30 Summary
reproduced features virial mass integrated X-ray flux approximate X-ray morphology temperature range (proxy of) BCG separation
approximate constraints collision axis inclined by i=40◦ wrt plane of the sky observed ∼0.5 Gyr after central passage mass ratio 1/6 – 1/8 Mach ∼3–4 small impact parameter (b<150 kpc), if any
Rubens Machado (IAG/USP) Simulations of the merging galaxy cluster Abell 3376 28 / 30 Summary
We have proposed a specific scenario of a dynamical history for the merging event of Abell 3376.
We have offered a possible combination of parameters that accounts for several of its features.
Machado & Lima Neto (2013)
Rubens Machado (IAG/USP) Simulations of the merging galaxy cluster Abell 3376 29 / 30 Perspectives
• Distribution of dark matter: • Mass maps from gravitational weak lensing • either corroborate this scenario or necessitate its improvement
acknowledgement:
Rubens Machado (IAG/USP) Simulations of the merging galaxy cluster Abell 3376 30 / 30 Perspectives
• Distribution of dark matter: • Mass maps from gravitational weak lensing • either corroborate this scenario or necessitate its improvement
“All models are wrong; some models are useful.”
Box & Draper (1987)
acknowledgement:
Rubens Machado (IAG/USP) Simulations of the merging galaxy cluster Abell 3376 30 / 30