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Chandra Observations of A2029: The Dark Matter Profile Down to below 0.01 r vir in an Unusually Relaxed Cluster

2003; IOP Publishing; Volume: 586; Issue: 1 Linguagem: Inglês

10.1086/367556

1538-4357

Aaron D. Lewis, David A. Buote, John T. Stocke,

Astronomy and Astrophysical Research

We have used a high spatial resolution Chandra observation to examine the core mass distribution of the unusually regular cD cluster A2029. This bright, nearby system is especially well suited for analysis of its mass distribution under the assumption of hydrostatic equilibrium; it exhibits an undisturbed, symmetric X-ray morphology and a single-phase intracluster medium (ICM). From the deprojected temperature and density profiles, we estimate the total mass and the contributions of the gas and dark matter (DM) components from less than 3'' to ~3' (<4.4-260 h kpc, 0.001-0.1rvir). The gas density profile is not adequately described by a single-β model fit because of an increase in the density at the center (r < 17 h kpc, <12''), but it is well fitted by either a double-β model, or a "cusped" β model. The temperature data increase as a function of radius and are well fitted by a Bertschinger & Meiksin profile and may be approximated by a power-law T(r) ∝ r, with αT = 0.27 ± 0.01.