X-ray spectroscopy of the Virgo Cluster out to the virial radius

By O. Urban, Norbert Werner, A. Simionescu, Steven W. Allen, H. Böhringer. 2011

136 citations recorded by the source corpus.

We present results from the analysis of a mosaic of 13 XMM–Newton pointings covering the Virgo Cluster from its centre northwards out to a radius r ∼ 1.2 Mpc (∼4. ◦ 5), reaching the virial radius and beyond. This is the first time that the properties of a modestly sized (Mvir ∼ 1.4 × 10 14 M� , kT ∼ 2.3 keV), dynamically young cluster have been studied out to the virial radius. The density profile of the cluster can be described by a surprisingly shallow power-law ne ∝ r −β with index β = 1.21 ± 0.12. In the radial range of 0.3rvir < r < rvir, the best-fitting temperature drops by roughly 60 per cent. Within a radius r < 450 kpc, the entropy profile has an approximate power law form K ∝ r 1.1 , as expected for gravitationally collapsed gas in hydrostatic equilibrium. Beyond r ∼ 450 kpc, however, the temperature and metallicity drop abruptly, and the entropy profile becomes flatter, staying consistently below the expected value by a factor of 2–2.5. The most likely explanation for the unusually shallow density profile and the flattening of entropy at large radius is clumping in the ICM. Our data provide direct observational evidence that the ICM is enriched by metals all the way to r200 to at least Z = 0.1 Z � .

Subfields: Astronomy and Astrophysics, Instrumentation

View Paper: https://www.semanticscholar.org/paper/999529dc22c723dcc61d36bc3d21d6f080f50769

How researchers see this paper

The researchers whose trusted networks rank it highest, strongest advocate first. Every researcher gets a different order.

In Astronomy and Astrophysics

In Instrumentation

Citations in the corpus

A new bound on axion-like particles (2017, methodology): “Outside this region, in the bulk of the Virgo cluster, we take the coherence lengths Li to be independent and randomly distributed with a power-law probability distribution for all i > 0, p(Li) ∼ { L−γi for Li > Lmin , 0 otherwise , (3.4) We extend this model to the virial radius: RN ≈ Rvirial = 1.0”
Planck intermediate results: V. Pressure profiles of galaxy clusters from the Sunyaev-Zeldovich effect (2012, unknown): “4 R 500 (George et al. 2009; Reiprich et al. 2009; Urban et al. 2011; Simionescu et al. 2011; Walker et al. 2012).”
THE NEXT GENERATION VIRGO CLUSTER SURVEY (NGVS). I. INTRODUCTION TO THE SURVEY (2012, methodology): “We note that Urban et al. (2011) have recently argued for a rather more compact and less massive cluster than indicated above, based on X-ray spectroscopy of the Virgo A subcluster using multiple overlapping XMM-Newton pointings extending 4.”
WIDE-FIELD PRECISION KINEMATICS OF THE M87 GLOBULAR CLUSTER SYSTEM (2011, background): “The ∼ 2.3 keV temperature of the X-ray gas around M87 also suggests rvir ∼ 1.4 Mpc and Mvir ∼ 1.7× 1014M⊙ from standard scaling relations (e.g., Urban et al. 2011).”