Uniformity in the Temperature and Metallicity of the X-Ray Emitting Gas in the Abell 1060 Cluster of Galaxies

Abstract

The results from ASCA observations of the Abell 1060 cluster of galaxies are presented. Spatially sorted X-ray spectra were used to derive the distributions of the temperature and metallicity in the X-ray emitting gas of the cluster. Within ~ 20' (or 400 kpc assuming HQ = 50 km s _1 Mpc -1 ) of the cluster center, the gas temperature has been found to be radially constant at 3.1ÌQ'5 keV (or 3.1 ± 0.2 keV within ~ 10'), and the 2-10 keV luminosity was estimated to be 2 x 10 43 erg s _1 . An upper limit on the cool emission component at the cluster center was derived to be 6 x 10 41 erg s _1 in 0.5-3 keV, assuming that it has a temperature of 1 keV. Although the metallicity is consistent with being radially constant at 0.3 relative to solar value, the present observations do not constrain the abundance well beyond 10', allowing values in the range from 0.2 to 0.4 solar value. There is some indication that O, Ne, and Si are more abundant than Fe and Ni, when compared to the solar-abundance ratios. These results suggest the importance of galactic winds driven by type-II supernovae during the early phase of galaxy formation. In comparison with the Centaurus and Virgo clusters, discussions are made concerning the possible role of the cD galaxy in generating a metal concentration and a cool X-ray component at the cluster center.

The distance to Hydra and Centaurus from surface brightness fluctuations: Consequences for the Great Attractor model

“…This is quite unlikely for a relaxed or nearly relaxed cluster as it is the Hydra cluster (e.g. Tamura et al 1996Tamura et al , 2000Yamasaki et al 2003).…”

ChandraObservation of the Central Galaxies in the A1060 Cluster of Galaxies

“…A1060 (Hydra I cluster, z = 0.0114) is an X-ray bright cluster of galaxies and is considered to be the archetype relaxed system. The ASCA and ROSAT observations of the cluster (Tamura et al 1996(Tamura et al , 2000 showed that the temperature of the ICM is constant at kT = 3.1 +0.3 −0.5 keV 1 with the X-ray luminosity L X = 2 × 10 43 erg s −1 in the 2-10 keV band. An upper limit for the flux of the cool component assuming kT = 1 keV is 6 × 10 41 erg s −1 in the energy band 0.5-3 keV.…”

X-Ray Properties of the Non-Cool-Core Cluster of Galaxies Abell 2147

“…Abell 1060 (at a redshift of z= 0.011), with a relatively circular shape [10], is by far the best studies non-cD cluster. In addition to early ASCA results [6], recent observations of this object, with Chandra [11], XMM-Newton [12], and Suzaku [13], revealed that its ICM is nearly isothermal at ~ 3.4 keV over the central region within ~75 kpc, with a mild outward temperature decrease. Given this, it is important to examine other non-cD clusters in comparison with Abell 1060 on one hand, and with cD clusters on the other hand.…”

“…These include the presence of a bright cool ICM component, a clear central enhancement in the X-ray surface brightness [3], and an increased ICM metallicity. Although these phenomena were once interpreted as evidence of cooling flows [3], the interpretation was thoroughly changed by observations with ASCA [4], and with subsequent X-ray missions [5][6][7]. The central ICM temperature decrease in these objects is now understood as a result of the stable co-existence of hot and cool plasma [8], and the central excess brightness is considered to reflect hierarchical potential shapes around cD clusters [7,9].…”