arXivDaily arXiv每日学术速递 周一至周五更新
arXiv周末暂无论文更新,休息一下吧,周末愉快~~
arXiv 1001.0871astro-ph.CO
收藏

从WMAP 5年观测资料看星系团Ysz-Lx和Ysz-M关系

The galaxy cluster Ysz-Lx and Ysz-M relations from the WMAP 5-yr data

J. -B. Melin, J. G. Bartlett, J. Delabrouille, M. Arnaud, R. Piffaretti, G. W. Pratt

摘要:

我们使用多频匹配滤波器,在WMAP 5年数据中,估算了893个ROSAT NORAS/REFLEX星系团的Sunyaev-Zel'dovich(SZ)通量,这些星系团的光度范围为Lx,[0.1-2.4]keV = 2 10^{41} - 3.5 10^{45} erg s^{-1}。通过使用最近从结合XMM-牛顿观测的REXCESS样品和数值模拟获得的通用压力分布,对过滤器进行空间优化。虽然这些星系团只能被边缘检测到,但我们能够在平均亮度/质量箱中的数据时可靠地测量SZ信号(>10 sigma)。箱平均SZ信号与亮度和X射线模型预测之间的比较显示出极好的一致性,这意味着SZ信号强度相对于集群的X射线性质的预期没有不足。使用单独的集群SZ通量测量,我们直接约束Y500-Lx和Y500-M500的关系,其中Y500是半径r500的球体上积分的康普顿y参数。首次在如此宽的质量范围内推导出的Y500-M500关系式在M500=3 × 10^{14} h^{1} Msun时具有归一化Y*500=[1.60 pm 0.19] 10^{-3} arcmin ^2,与X射线预测的1.54 10^{-3} arcmin ^2非常吻合,和质量指数α =1.79 μ m0.17,与5/3的自相似预期一致。由于样品的红移范围有限,对红移指数的约束很弱,尽管它们与自相似演化相容。

英文摘要:

We use multifrequency matched filters to estimate, in the WMAP 5-year data, the Sunyaev-Zel'dovich (SZ) fluxes of 893 ROSAT NORAS/REFLEX clusters spanning the luminosity range Lx,[0.1-2.4]keV = 2 10^{41} - 3.5 10^{45} erg s^{-1}. The filters are spatially optimised by using the universal pressure profile recently obtained from combining XMM-Newton observations of the REXCESS sample and numerical simulations. Although the clusters are individually only marginally detected, we are able to firmly measure the SZ signal (>10 sigma) when averaging the data in luminosity/mass bins. The comparison between the bin-averaged SZ signal versus luminosity and X-ray model predictions shows excellent agreement, implying that there is no deficit in SZ signal strength relative to expectations from the X-ray properties of clusters. Using the individual cluster SZ flux measurements, we directly constrain the Y500-Lx and Y500-M500 relations, where Y500 is the Compton y-parameter integrated over a sphere of radius r500. The Y500-M500 relation, derived for the first time in such a wide mass range, has a normalisation Y*500=[1.60 pm 0.19] 10^{-3} arcmin^2 at M500=3 10^{14} h^{1} Msun, in excellent agreement with the X-ray prediction of 1.54 10^{-3} arcmin^2, and a mass exponent of alpha=1.79 pm 0.17, consistent with the self-similar expectation of 5/3. Constraints on the redshift exponent are weak due to the limited redshift range of the sample, although they are compatible with self-similar evolution.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

↑