A multiphase model for the intracluster medium
dc.contributor.author | Nagai, Daisuke | en_US |
dc.contributor.author | Sulkanen, Martin E. | en_US |
dc.contributor.author | Evrard, August E. | en_US |
dc.date.accessioned | 2008-08-14T19:09:54Z | |
dc.date.available | 2008-08-14T19:09:54Z | |
dc.date.issued | 2000-07-21 | en_US |
dc.identifier.citation | Nagai, D; Sulkanen, ME; Evrard, AE. (2000). Monthly Notices of the Royal Astronomical Society, 316:(1) 120-128. <http://hdl.handle.net/2027.42/60571> | en_US |
dc.identifier.issn | 0035-8711 | en_US |
dc.identifier.uri | http://arxiv.org/abs/astro-ph/9903308 | en_US |
dc.identifier.uri | https://hdl.handle.net/2027.42/60571 | |
dc.description.abstract | Constraints on the clustered mass density Omega(m) of the Universe derived from the observed population mean intracluster gas fraction [f(ICM)] of X-ray clusters may be biased by reliance on a single-phase assumption for the thermodynamic structure of the intracluster medium (ICM). We propose a descriptive model for multiphase structure in which a spherically symmetric ICM contains isobaric density perturbations with a radially dependent variance sigma(2)(r) = sigma(c)(2)(1 + r(2)/r(c)(2))(-epsilon). The model extends the work of Gunn & Thomas, which assumed radially independent density fluctuations. The main limitation of the model is its lack of connection to ICM dynamics. Fixing the X-ray emission profile and emission-weighted temperature, we explore two independently observable signatures of the model in the {sigma(c), epsilon} space. For bremsstrahlung-dominated emission, the central Sunyaev-Zeldovich (SZ) decrement in the multiphase case is increased over the single-phase case, and multiphase X-ray spectra in the range 0.1-20 keV are flatter in the continuum and exhibit stronger low-energy emission lines than their single-phase counterpart. We quantify these effects for a fiducial 10(8) K cluster and demonstrate how the combination of SZ and X-ray spectroscopy can be used to identify a preferred location {<(sigma)over cap>(c), <(epsilon)over cap>} in the model plane. From these parameters, the correct value of [f(ICM)] in the multiphase model results, allowing an unbiased estimate of Omega(m) to be recovered. The degree of consistency of current determinations of the Hubble constant via SZ and X-ray observations with values determined by other methods implies that biases in ICM gas fractions are not large. | en_US |
dc.format.extent | 340315 bytes | |
dc.format.extent | 18 bytes | |
dc.format.mimetype | application/pdf | |
dc.format.mimetype | text/plain | |
dc.publisher | Blackwell Science Ltd | en_US |
dc.subject | Galaxies : Clusters : General | en_US |
dc.subject | Intergalactic Medium | en_US |
dc.subject | X-rays : Galaxies | en_US |
dc.title | A multiphase model for the intracluster medium | en_US |
dc.type | Article | en_US |
dc.subject.hlbsecondlevel | Physics | en_US |
dc.subject.hlbtoplevel | Science | en_US |
dc.description.peerreviewed | Peer Reviewed | en_US |
dc.contributor.affiliationum | Univ Michigan, Dept Phys, Ann Arbor, MI 48109 USA | en_US |
dc.contributor.affiliationother | Univ Chicago, Chicago, IL 60637 USA | en_US |
dc.contributor.affiliationother | NASA, Xray Astron Grp, Space Sci Lab, George C Marshall Space Flight Ctr, Huntsville, AL 35812 USA | en_US |
dc.contributor.affiliationumcampus | Ann Arbor | en_US |
dc.description.bitstreamurl | http://deepblue.lib.umich.edu/bitstream/2027.42/60571/1/Nagai1999Multiphase.pdf | |
dc.owningcollname | Astrophysics (Physics, Department of) |
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