Philip J. Humphrey (UCI)

Tracing the Gas to the Virial Radius (R100) in a

Fossil Group

arXiv:1106.3322

David A. Buote (UC Irvine), Fabrizio Brighenti (Bologna), Hélène M. L. G. Flohic (U Chile), Fabio Gastaldello (Milan), William G. Mathews (UCSC)

David A. Buote (UC Irvine), Fabrizio Brighenti (Bologna), Hélène M. L. G. Flohic (U Chile), Fabio Gastaldello (Milan), William G. Mathews (UCSC)

David A. Buote (UC Irvine), Fabrizio Brighenti (Bologna), Hélène M. L. G. Flohic (U Chile), Fabio Gastaldello (Milan), William G. Mathews (UCSC)

David A. Buote (UC Irvine), Fabrizio Brighenti (Bologna), Hélène M. L. G. Flohic (U Chile), Fabio Gastaldello (Milan), William G. Mathews (UCSC)

Introduction

Cluster outskirts…

•Well-behaved? (eg. Reiprich et al,

2009)

•Non-relaxed? (eg. Bautz et al, 2009;

Kawaharada et al 2010)

•Clumpy? (eg. Simionescu et al 2011;

Urban et al. 2011)

Fossil group (Vikhlinin 99) => relaxed

R500

XIS

0

RXJ1159+5531

Chandr

a

Residuals plot

1.2 Mpc = Rvir

90 kpc = 0.08

Rvir

Vikhlinin et al

(2006)

Chandra

Spectral analysis

XIS

0

Chandr

a

Suzaku

Hot

gas

X-ray

background

Instrumental

background

Spectral analysis

Chandr

a

Galactic/

local

CXB

Detected +

undetected

Chandr

aSuzakuAgreement

!

Results

(Vikhlinin et al

2006)

Chandr

aSuzak

u

Fit projected kT,

densityProject 3D gas model onto

skyAgrees with deprojection

analysis

R500

No flattening at large

radii

ResultsConstruct hydrostatic model (Buote talk)

Rvir = 1120±40 kpc, consistent with past

work

Add in central galaxy

Add in other galaxies (Vikhlinin

99)

Add in IntraCluster Light (Purcell

07)

Cosmological

fb

Baryonic closure within

Rvir

3

2

cos

)(

mob

gscaled f

rfSS

Robustness of results

Solar wind

Charge

Exchange?

CXB model

shape?

Robustness of results

Results appear

robust!

Conclusions

Trace the gas to Rvir RXJ1159 in

single Suzaku pointing

Robust results

Well-behaved at large radii

Fossil groups optimal?

Efficient observing strategy