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Tracing the Gas to the Virial Radius (R 100 ) in a Fossil Group. Philip J. Humphrey (UCI). David A. Buote (UC Irvine), Fabrizio Brighenti (Bologna), H élène M. L. G. Flohic (U Chile), Fabio Gastaldello (Milan), William G. Mathews (UCSC).
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Tracing the Gas to the Virial Radius (R100) in a Fossil Group Philip J. Humphrey (UCI) 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) arXiv:1106.3322
Introduction ? Cluster outskirts… • Well-behaved? (eg. Reiprich et al, 2009) • Clumpy? (eg. Simionescu et al 2011; Urban et al. 2011) • Non-relaxed? (eg. Bautz et al, 2009; Kawaharada et al 2010)
RXJ1159+5531 Fossil group (Vikhlinin 99) => relaxed Residuals plot R500 1.2 Mpc = Rvir 90 kpc = 0.08 Rvir Chandra Chandra XIS 0 Vikhlinin et al (2006)
Spectral analysis Hot gas X-ray background Instrumental background Chandra XIS 0 Suzaku
Spectral analysis Chandra Suzaku • Agreement! CXB Galactic/ local Detected + undetected Chandra
Results Fit projected kT, density Chandra Project 3D gas model onto sky (Vikhlinin et al 2006) Suzaku Agrees with deprojection analysis No flattening at large radii R500
Results Baryonic closure within Rvir Construct hydrostatic model (Buote talk) Rvir = 1120±40 kpc, consistent with past work Cosmological fb Add in central galaxy Add in other galaxies (Vikhlinin 99) Add in IntraCluster Light (Purcell 07)
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 Well-behaved at large radii Robust results Fossil groups optimal? Efficient observing strategy