The XMM Cluster Survey: The Stellar Mass Assembly of Fossil Galaxies
Craig D. Harrison, Christopher J. Miller, Joseph W. Richards, E. J. Lloyd-Davies, Ben Hoyle, A. Kathy Romer, Nicola Mehrtens, Matt Hilton, John P. Stott, Diego … 展开作者
Craig D. Harrison, Christopher J. Miller, Joseph W. Richards, E. J. Lloyd-Davies, Ben Hoyle, A. Kathy Romer, Nicola Mehrtens, Matt Hilton, John P. Stott, Diego Capozzi, Chris A. Collins, Paul-James Deadman, Andrew R. Liddle, Martin Sahlén, S. Adam Stanford, Pedro T. P. Viana
This paper presents both the result of a search for fossil systems (FSs) within the XMM Cluster Survey and the Sloan Digital Sky Survey and the results of a study of the stellar mass assembly and stellar populations of their fossil galaxies. In total, 17 groups and clusters are identified at z < 0.25 with large magnitude gaps between the first and fourth brightest galaxies. All the information necessary to classify these systems as fossils is provided. For both groups and clusters, the total and fractional luminosity of the brightest galaxy is positively correlated with the magnitude gap. The brightest galaxies in FSs (called fossil galaxies) have stellar populations and star formation histories which are similar to normal brightest cluster galaxies (BCGs). However, at fixed group/cluster mass, the stellar masses of the fossil galaxies are larger compared to normal BCGs, a fact that holds true over a wide range of group/cluster masses. Moreover, the fossil galaxies are found to contain a significant fraction of the total optical luminosity of the group/cluster within 0.5R200, as much as 85%, compared to the non-fossils, which can have as little as 10%. Our results suggest that FSs formed early and in the highest density regions of the universe and that fossil galaxies represent the end products of galaxy mergers in groups and clusters. The online FS catalog can be found at http://www.astro.ljmu.ac.uk/~xcs/Harrison2012/XCSFSCat.html.
We investigate the use of the halo mass-gap statistic --- defined as the logarithmic difference in mass between the host halo and its most massive satellite subhalo --- as a probe of halo age and concentration. A cosmological N-body simulation is used to study N ~25, 000 group/cluster sized halos in the mass range 10^12.5 < M_halo/M_sol < 10^14.5. In agreement with previous work, we find that halo mass-gap is related to halo formation time and concentration. On average, older and more highly concentrated halos have larger halo mass-gaps, and this trend is stronger than the mass-concentration r…
We investigate the properties of the hot gas in four fossil galaxy systems detected at high significance in the Planck Sunyaev-Zeldovich (SZ) survey. XMM-Newton observations reveal overall temperatures of kT ~ 5-6 keV and yield hydrostatic masses M500,HE > 3.5 x 10e14 Msun, confirming their nature as bona fide massive clusters. We measure the thermodynamic properties of the hot gas in X-rays (out to beyond R500 in three cases) and derive their individual pressure profiles out to R ~ 2.5 R500 with the SZ data. We combine the X-ray and SZ data to measure hydrostatic mass profiles and to examine …
Fresh Activity in Old Systems: Radio AGN in Fossil Groups of Galaxies
我们提出了第一个系统的1.4 GHz甚大阵射电连续调查的化石星系群候选人。这些维里化系统被认为是在过去的十亿年中通过星系群成员合并成一个单一的、孤立的、巨大的椭圆星系而聚集起来的，并具有扩展的热X射线晕。我们使用SDSS Data Release 7的新光度和光谱数据来确定其中三个候选者显然不是化石群。在剩下的30个候选星系中，有67%的星系在其主要椭圆星系的中心有一个射电强（L_1.4GHz > 10^23 W Hz^-1）的活动星系核（AGN）。我们发现活动星系核的射电光度和晕的X射线光度之间存在弱的相关性，这表明活动星系核有助于能量沉积到群内介质中。我们只找到了中央椭圆星系的无线电和光学光度之间的相关性，当我们包括X射线选择，椭圆占主导地位的非化石组，这表明活动星系核的强度和大规模组装历史的群体之间的弱关系。在光学、X射线和射电光度方面，化石群中占主导地位的椭圆星系平均比正常群椭圆星系亮一个数量级，我们的研究结果与以前的结果一致，即椭圆星系中的射电大声部分与人口的恒星质量有关。化石群目前的活动水平表明，活动星系核的燃料供应在上一次重大合并之后仍在继续。我们讨论了几种可能性燃料的活动星系核在目前的时代。
The Cluster HEritage project with XMM-Newton - Mass Assembly and Thermodynamics at the Endpoint of structure formation (CHEX-MATE) is a three mega-second Multi-Year Heritage Programme to obtain X-ray observations of a minimally-biased, signal-to-noise limited sample of 118 galaxy clusters detected by Planck through the Sunyaev-Zeldovich effect. The programme, described in detail in this paper, aims to study the ultimate products of structure formation in time and mass. It is composed of a census of the most recent objects to have formed (Tier-1: 0.05 < z < 0.2; 2 x 10e14 M_sun < M_500 < 9 x 10…
It is well established that particle acceleration by shocks and turbulence in the intra-cluster medium can produce cluster-scale synchrotron emitting sources. However, the detailed physics of these particle acceleration processes is still not well understood. One of the main open questions is the role of fossil relativistic electrons that have been deposited in the intra-cluster medium by radio galaxies. These synchrotron-emitting electrons are very difficult to study, as their radiative life time is only tens of Myrs at GHz frequencies, and are therefore a relatively unexplored population. De…
We present the characterisation of the massive cluster ClG-J$104803.7+313843$ at $z=0.76$ performed using a serendipitous XMM-Newton observation. High redshift and massive objects represent an ideal laboratory to benchmark our understanding of how cluster form and assembly formation driven mainly by gravity.Leveraging the high throughput of XMM-Newton we were firstly able to determine the redshift of the object, shedding light on ambiguous photometric redshift associations. We investigated the morphology of this cluster which shows signs of merging activities in the outskirts and a flat core. …
The fraction of distant disks and mergers is still debated, while 3D-spectroscopy is revolutionizing the field. However its limited spatial resolution imposes a complimentary HST imagery and a robust analysis procedure. When applied to observations of IMAGES galaxies at z=0.4-0.8, it reveals that half of the spiral progenitors were in a merger phase, 6 billion year ago. The excellent correspondence between methodologically-based classifications of morphologies and kinematics definitively probes a violent origin of disk galaxies as proposed by Hammer et al. (2005). Examination of nearby galaxy …
We study the global and radial stellar mass assembly of eight zoomed-in MW-sized galaxies produced in Hydrodynamics cosmological simulations. The disk-dominated galaxies (4) show a fast initial stellar mass growth in the innermost parts, driven mostly by in-situ SF, but since $z\sim2-1$ the SF enters in a long-term quenching phase. The outer regions follow this trend but more gentle as more external they are. As the result, the radial stellar mass growth is highly inside-out due to both the inside-out structural growth and inside-out SF quenching. The half-mass radius evolves fast; for instanc…
Context: Chandra observations of the Abell 3411-3412 merging system have revealed an outbound bullet-like sub-cluster in the northern part and many surface brightness (SB) edges at the southern periphery, where multiple diffuse sources are also reported from radio observations. Notably, a south-eastern radio relic associated with fossil plasma from a radio galaxy and with a detected X-ray edge provides direct evidence of shock re-acceleration. The properties of the reported X-ray edges have yet to be constrained from a thermodynamic view. Aims: We use the XMM-Newton and Suzaku observations to …
XMM-Newton observations of ten high-redshift CAMIRA clusters of galaxies
Nara Women’s University（奈良女子大学）；Universität Bonn（波恩大学）；Nagoya University（名古屋大学）；Hiroshima University（广岛大学）；Chiba University（千叶大学）；Ritsumeikan University（立命馆大学）；Academia Sinica Institute of Astronomy and Astrophysics（中央研究院天文及天文物理研究所）
CHEX-MATE: towards a consistent universal pressure profile and cluster mass reconstruction
IRAP, CNRS, Université de Toulouse, CNES, UT3-UPS（IRAP, 法国国家科学研究中心, 图卢兹大学）；Université Paris-Saclay, Université Paris Cité, CEA, CNRS, AIM（巴黎萨克雷大学, 巴黎西岱大学, 法国原子能和替代能源委员会, 法国国家科学研究中心）；Université Grenoble Alpes, CNRS, LPSC-IN2P3（格勒诺布尔阿尔卑斯大学, 法国国家科学研究中心）；Université Paris-Saclay, CNRS, Institut d’Astrophysique Spatiale（巴黎萨克雷大学, 法国国家科学研究中心, 空间天体物理研究所）；INAF, Istituto di Astrofisica Spaziale e Fisica Cosmica di Milano（意大利国家天体物理研究所, 米兰空间天体物理与宇宙物理研究所）；Dipartimento di Fisica, Università degli studi di Roma Tor Vergata（罗马托尔维加塔大学物理系）；INFN, Sezione di Roma ‘Tor Vergata’（意大利国家核物理研究所, 罗马托尔维加塔分部）；Sapienza Università di Roma（罗马智慧大学）
The Shapley Supercluster ($\langle z \rangle\approx0.048$) contains several tens of gravitationally bound clusters and groups, making it it is an ideal subject for radio studies of cluster mergers. We used new high sensitivity radio observations to investigate the less energetic events of mass assembly in the Shapley Supercluster from supercluster down to galactic scales. We created total intensity images of the full region between A 3558 and A 3562, from $\sim 230$ to $\sim 1650$ MHz, using ASKAP, MeerKAT and the GMRT, with sensitivities ranging from $\sim 6$ to $\sim 100$ $μ$Jy beam$^{-1}$. …
A multiwavelength study of an early galaxy group merger in COSMOS revealed by two tailed radio galaxies at z = 0.35
University of Zagreb（萨格勒布大学）；Aalto University（阿尔托大学）；University of Helsinki（赫尔辛基大学）；INAF – Osservatorio di Astrofisica e Scienza dello Spazio di Bologna（意大利国家天体物理研究所博洛尼亚天文与空间科学观测站）
