The Beautiful Mess in Abell 2255

被引：78

作者：

Botteon, A. ^{[1
,2
]}

Brunetti, G. ^{[2
]}

van Weeren, R. J. ^{[1
]}

Shimwell, T. W. ^{[1
,3
]}

Pizzo, R. F. ^{[3
]}

Cassano, R. ^{[2
]}

Iacobelli, M. ^{[3
]}

Gastaldello, F. ^{[4
]}

Birzan, L. ^{[5
]}

Bonafede, A. ^{[2
,6
]}

Brueggen, M. ^{[5
]}

Cuciti, V ^{[5
]}

Dallacasa, D. ^{[2
,6
]}

de Gasperin, F. ^{[5
]}

Di Gennaro, G. ^{[1
]}

Drabent, A. ^{[7
]}

Hardcastle, M. J. ^{[8
]}

Hoeft, M. ^{[7
]}

Mandal, S. ^{[1
]}

Rottgering, H. J. A. ^{[1
]}

Simionescu, A. ^{[1
,9
,10
]}

机构：

[1] Leiden Univ, Leiden Observ, POB 9513, NL-2300 RA Leiden, Netherlands

[2] INAF IRA, Via P Gobetti 101, I-40129 Bologna, Italy

[3] Netherlands Inst Radio Astron, ASTRON, Postbus 2, NL-7990 AA Dwingeloo, Netherlands

[4] INAF IASF Milano, Via A Corti 12, I-20133 Milan, Italy

[5] Univ Hamburg, Hamburger Sternwarte, Gojenbergsweg 112, D-21029 Hamburg, Germany

[6] Univ Bologna, Dept Fis & Astron, Via P Gobetti 93-2, D-40129 Hamburg, Germany

[7] Thuringer Landessternwarte, Sternwarte 5, D-07778 Tautenburg, Germany

[8] Univ Hertfordshire, Ctr Astrophys Res, Coll Lane, Hatfield AL10 9AB, Herts, England

[9] SRON Netherlands Inst Space Res, Sorbonnelaan 2, NL-3584 CA Utrecht 5, Netherlands

[10] Univ Tokyo, Kavli Inst Phys & Math Universe WPI, Kashiwa, Chiba 2778583, Japan

来源：

ASTROPHYSICAL JOURNAL | 2020年 / 897卷 / 01期

基金：

英国科学技术设施理事会; 爱尔兰科学基金会;

关键词：

Galaxy clusters; Abell clusters; Intracluster medium; Extragalactic radio sources; Radio astronomy; Radio interferometry; Extended radiation sources; Tailed radio galaxies; X-ray astronomy; Non-thermal radiation sources; MAGNETIC-FIELD; RADIO HALO; PARTICLE-ACCELERATION; LINEAR-REGRESSION; GALAXY CLUSTERS; COMA CLUSTER; ORIGIN; EMISSION; CALIBRATION; TURBULENCE;

D O I：

10.3847/1538-4357/ab9a2f

中图分类号：

P1 [天文学];

学科分类号：

0704 ;

摘要：

We present LOFAR observations of one of the most spectacular objects in the radio sky: Abell 2255. This is a nearby (z = 0.0806) merging galaxy cluster hosting one of the first radio halos ever detected in the intracluster medium (ICM). The deep LOFAR images at 144 MHz of the central similar to 10 Mpc(2)region show a plethora of emission on different scales, from tens of kiloparsecs to above megaparsec sizes. In this work, we focus on the innermost region of the cluster. Among the numerous interesting features observed, we discover remarkable bright and filamentary structures embedded in the radio halo. We incorporate archival WSRT 1.2 GHz data to study the spectral properties of the diffuse synchrotron emission and find a very complex spectral index distribution in the halo spanning a wide range of values. We combine the radio data with Chandra observations to investigate the connection between the thermal and nonthermal components by quantitatively comparing the radio and X-ray surface brightness and the spectral index of the radio emission with the thermodynamical quantities of the ICM. Despite the multitude of structures observed in the radio halo, we find that the X-ray and radio emission are overall well correlated. The fact that the steepest spectrum emission is located in the cluster center and traces regions with high entropy possibly suggests the presence of seed particles injected by radio galaxies that are spread in the ICM by the turbulence generating the extended radio halo.

引用

页数：14

共 81 条

[21] Deep Very Large Array Observations of the Merging Cluster CIZA J2242.8+5301: Continuum and Spectral Imaging [J].

Di Gennaro, G. ;

van Weeren, R. J. ;

Hoeft, M. ;

Kang, H. ;

Ryu, D. ;

Rudnick, L. ;

Forman, W. ;

Rottgering, H. J. A. ;

Brueggen, M. ;

Dawson, W. A. ;

Golovich, N. ;

Hoang, D. N. ;

Intema, H. T. ;

Jones, C. ;

Kraft, R. P. ;

Shimwell, T. W. ;

Stroe, A. .

ASTROPHYSICAL JOURNAL, 2018, 865 (01)

[22]

Dolag K, 2000, ASTRON ASTROPHYS, V362, P151

[23] Rise and fall of radio haloes in simulated merging galaxy clusters [J].

Donnert, J. ;

Dolag, K. ;

Brunetti, G. ;

Cassano, R. .

MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY, 2013, 429 (04) :3564-3569

[24] The XMM cluster outskirts project (X-COP) [J].

Eckert, D. ;

Ettori, S. ;

Pointecouteau, E. ;

Molendi, S. ;

Paltani, S. ;

Tchernin, C. .

ASTRONOMISCHE NACHRICHTEN, 2017, 338 (2-3) :293-298

[25]

Ensslin T. A., 1999, GARCH MAX PLANCK I E

[26]

Ensslin TA, 2001, ASTRON ASTROPHYS, V366, P26, DOI 10.1051/0004-6361:20000198

[27]

Feretti L, 1997, ASTRON ASTROPHYS, V317, P432

[28] Spectral index maps of the radio halos in Abell 665 and Abell 2163 [J].

Feretti, L ;

Orrù, E ;

Brunetti, G ;

Giovannini, G ;

Kassim, N ;

Setti, G .

ASTRONOMY & ASTROPHYSICS, 2004, 423 (01) :111-119

[29] The giant radio halo in Abell 2163 [J].

Feretti, L ;

Fusco-Femiano, R ;

Giovannini, G ;

Govoni, F .

ASTRONOMY & ASTROPHYSICS, 2001, 373 (01) :106-112

[30] The relation between gas density and velocity power spectra in galaxy clusters: High-resolution hydrodynamic simulations and the role of conduction [J].

Gaspari, M. ;

Churazov, E. ;

Nagai, D. ;

Lau, E. T. ;

Zhuravleva, I. .

ASTRONOMY & ASTROPHYSICS, 2014, 569

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