Chemical Discriminators of Cold Fronts in Clusters of Galaxies: The Case for A3667

Renato DupkeUniversity of Michigan, Ann Arbor

Alex Vikhlinin and Maxim MarkevitchCfA

P = n kT = cont

External Mechanisms (Markevitch et al. 2000)

Abell 496 is a cD cluster at z=0.033, has a cold core. The image below shows the main cold front towards the North and other sharp edges (weaker cold fronts) towards SE and SW, indicated by the green arrows below.

“Classic” Cold Fronts

Abell 3667 & A2142 at z~0.06, have indications of an on-going merger.

Induced Internal Mechanisms (Tittley et al. 2005)

From LCDM w/ cooling30:1 mass ratio200kpc boxsize50Mpc time step

Ascasibar & Markevitch 2006 – DM blob passage – MDM2/MDM1=5, b=500kpc, panel size 1 Mpc, Temp scale shown, arrows show gas velocity wrt DM center

parallel PM tree+SPH code GADGET2

500km/s

Si/S agrees w/ other ratios

Dupke et al. 2007

Flint Blob, 2006

Heinz et al. 2003

Temperature - keV

O/Fe

A 3667

A 3667 ~ 350 ksec

A 3667 Temperature keV

A 3667 Temperature 7k - keV

A 3667

A 3667 Fe

A 3667 O/Fe

A 3667

A 3667 – Si/Fe 7k

O/Fe

Si/Fe

What Does Cosmology Predict?

Pawl, Evrard & Dupke 2005

Dashed Max ΔV, Dot All pointing pairs recovered from the perfect spectra after passing through Suzaku responses.

f(>ΔV) α ΔV-4

vce.physics.lsa.umich.edu

VCE is a prototype theoretical counterpart to the HEASARC archive for X-ray emitting clusters. 68 preheated simulated clusters. With 14 outputs per run, this creates a set of 1000 instances of clusters covering 0<z<2

• Analysis of the distribution of SN Type enrichment can be used as an additional tool to corroborate the presence of and discriminate between different types of cold fronts in clusters.

• For A496 the combination of temperature distribution and numerical simulations suggests that the cold fronts are formed by sloshing due to the off-center passage of a massive dark clump 0.5 Gy ago. The analysis of SN type enrichment is also consistent with that scenario.

• Abundance ratio distribution across the cold front from a deep observation of A3667 are consistent with the standard model for cold front formation, i.e., remnant cores of subsonic or transonic mergers.

Summary