An X-ray review of MS 1054–0321: Hot or not?

Abstract

Abstract. XMM-Newton observations are presented for the z = 0.83 cluster of galaxies MS 1054−0321, the highest redshift cluster in the Einstein Extended Medium Sensitivity Survey (EMSS). The temperature inferred by the XMM-Newton data, T = 7.2 +0.7 −0.6 keV, is much lower than the temperature previously reported from ASCA data, T = 12.3 Donahue et al. 1998), and a little lower than the Chandra temperature, T = 10.4 +1.7 −1.5 keV, determined by Jeltema et al. 2001. The discrepancy between the newly derived temperature and the previously derived temperatures is discussed in detail. If one allows the column density to be a free parameter, then the best fit temperature becomes T = 8.6+1.2 −1.1 keV, and the best fit column density becomes N H = 1.33−0.14 × 10 20 atoms cm −2 . The iron line is well detected in the XMM-Newton spectrum with a value for the abundance of Z = 0.33−0.18 Z , in very good agreement with previous determinations. The derived XMM X-ray luminosity for the overall cluster in the 2-10 keV energy band is L X = (3.81 ± 0.19) × 10 44 h −2 erg s −1 while the bolometric luminosity is L BOL = (8.05 ± 0.40) × 10 44 h −2 erg s −1 . The XMM-Newton data confirm the substructure in the cluster X-ray morphology already seen by ROSAT and in much more detail by Chandra. We find that only two of the three clumps detected in the weak lensing mass reconstruction image are visible in X-rays, as already noted by Jeltema et al. (2001). The central weak lensing clump is coincident with the main cluster component and has a temperature T = 8.1 +1.3 −1.2 keV. The western weak lensing clump coincides with the western X-ray component which is much cooler with a temperature T = 5.6 +0.8 −0.6 keV. The optically measured velocity dispersion, obtained from 145 cluster redshifts, is consistent with the velocity dispersion expected from the σ V − T X relationship once the XMM-Newton temperature is used. MS 1054−0321 fits well in the σ ∝ T 1/2 correlation available in the literature and derived from information collected for all clusters at redshfits of z ≤ 1.27 known today and with a measured X-ray temperature. The cluster temperature seems to be commensurate with the predictions from its X-ray luminosity from the L X − T X relation of local clusters. Given the newly determined temperature, MS 1054−0321 is no longer amongst the hottest clusters known.

The gas distribution in the high-redshift cluster MS 1054−0321

“…An investigation of the temperature structure of MS 1054-0321 using XMM-Newton (Gioia et al 2004) indicated a temperature for the whole cluster of 7.2 +0.7 −0.6 keV, lower than any of the temperatures reported previously. The two significant clumps already seen by the ROSAT and the Chandra satellites were also seen in the XMM-Newton data.…”

ThePlanckSZ Cluster Catalog: expected X-ray properties

“…MS 1054-0321 (Gioia et al 2004): the XMM-Newton observations yield temperature, redshift (through observation of the iron line in the X-ray spectrum) and flux estimates of T = 7.2 +0.7 −0.6 keV, z = 0.847 +0.057 −0.040 and f X [0.5,2] keV = (1.9±0.09)×10 −13 erg/s/cm 2 , respectively; and they also provide a detailed image showing several components to the cluster's structure. The effective exposure time needed was ∼25 ks.…”

Clusters at Half Hubble Time: Galaxy Structure and Colors in RX J0152.7−1357 and MS 1054−03

“…MS 1054À03, the most X-ray-luminous cluster in the Einstein Extended Medium Sensitivity Survey (Gioia et al 1990;Gioia & Luppino 1994), has also been the target of numerous X-ray studies and has a similarly complex morphology (Donahue et al 1998;Jeltema et al 2001), although in its case the merger is more advanced and the total mass is roughly twice that of RX J0152.7À1357. While estimates of the temperature of MS 1054À03 have varied widely (see Gioia et al 2004 for an X-ray review of this cluster), the most recent determination using the latest Chandra calibration gives 8:9 þ1:0 À0:8 keV (Jee et al 2005b). Its mean redshift is z ¼ 0:831 based on $150 members (van Dokkum et al 2000; K.-V. Tran et al 2006, in preparation).…”