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相关论文: A Deep Radio Survey of Abell 2125 II: Accelerated …

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We report a detailed optical study of the clusters Abell 2125 and 2645. Both clusters have z=0.25 and richness class 4, yet contrast strongly in blue fraction and radio galaxy population. We find 27 spectroscopically confirmed radio…

天体物理学 · 物理学 2009-10-31 F. N. Owen , M. J. Ledlow , W. C. Keel , G. E. Morrison

Deep VLA 1.4 GHz radio continuum imaging of Abell 2255 is presented. This cluster is among the better nearby candidates for rich cluster-cluster merger systems, with evidence including an elongated X-ray morphology, the presence of a radio…

天体物理学 · 物理学 2009-11-07 Neal Miller , Frazer Owen

We present LOFAR data from 110--180~MHz of the merging galaxy cluster Abell 1682, alongside archival optical, radio and X-ray data. Our 6 arc-second resolution images at low frequencies reveal new structures associated with numerous radio…

The structure of the universe is believed to have formed by clustering hierarchically from small to large scales. Much of this evolution occurs very slowly but at a few special times more, rapid, violent activity may occur as major subunits…

天体物理学 · 物理学 2009-11-10 Q. Daniel Wang , Frazer Owen , Michael Ledlow , William Keel

We present 371 galaxy velocities in the field of the very rich cluster Abell 2125 (z~0.25). These were determined using optical spectroscopy collected over several years from both the WIYN 3.5m telescope and NOAO Mayall 4m telescope. Prior…

Diffuse radio emission has been found in many galaxy clusters, predominantly in massive systems which are in the state of merging. The radio emission can usually be classified as relic or halo emission, which are believed to be related to…

Radio continuum emission at 1.4 GHz was used to identify active galaxies in a sample of 20 nearby Abell clusters. The radio emission indicates either an active galactic nucleus or current star formation, and optical spectroscopy was used to…

天体物理学 · 物理学 2007-05-23 Neal A. Miller

Abell 2256 is a nearby (z~0.06), rich cluster of galaxies with fascinating observed properties across a range of wavelengths. Long believed to represent a cluster merger, recent X-ray and optical results have suggested that in addition to…

天体物理学 · 物理学 2009-11-07 Neal Miller , Frazer Owen , John Hill

We use radio, near-IR, optical, and X-ray observations to examine dynamic processes in the central region of Abell 2125. In addition to the central triple, including members of both major dynamical subsystems identified from a redshift…

天体物理学 · 物理学 2008-11-26 F. N. Owen , W. C. Keel , Q. D. Wang , M. J. Ledlow , G. E. Morrison

Massive, merging galaxy clusters often host giant, diffuse radio sources that arise from shocks and turbulence; hence, radio observations can be useful for determining the merger state of a cluster. In preparation for a larger study, we…

We present the analysis of our 13 and 22 cm ATCA observations of the central region of the merging galaxy cluster A3921 (z=0.094). We investigated the effects of the major merger between two sub-clusters on the star formation (SF) and radio…

天体物理学 · 物理学 2009-11-11 C. Ferrari , R. W. Hunstead , L. Feretti , S. Maurogordato , S. Schindler

The connection of cluster mergers with the presence of extended, diffuse radio sources in galaxy clusters is still being debated. In this paper we aim to obtain new insights into the internal dynamics of Abell 959, showing evidence of a…

宇宙学与河外天体物理 · 物理学 2009-11-13 W. Boschin , R. Barrena , M. Girardi

(Abridged) We report on the properties of radio-selected galaxies within 30 very-rich Abell clusters with z < 0.25. These radio data sample the ultra-faint (L(1.4) > 2E22 W/Hz) radio galaxy population with M_R < -21 using the well-known…

天体物理学 · 物理学 2009-11-07 Glenn E. Morrison , Frazer N. Owen

Galaxy clusters with signs for a recent merger show in many cases extended diffuse radio features. This emission originates from relativistic electrons which suffer synchrotron losses due to the intra-cluster magnetic field. The mechanisms…

星系天体物理 · 物理学 2015-02-11 A. Drabent , M. Hoeft , R. F. Pizzo , A. Bonafede , R. J. van Weeren , U. Klein

We are conducting a deep radio survey of a sample of 25 distant ($0.5<z<1$) clusters of galaxies. Here we present a progress report. So far 17 of 25 clusters have been observed, to varying depths. We have found 33 radio sources within 0.3…

Abell 1995 is a puzzling galaxy cluster hosting a powerful radio halo, but it has not yet been recognized as a obvious cluster merger, as usually expected for clusters with diffuse radio emission. We aim at an exhaustive analysis of the…

宇宙学与河外天体物理 · 物理学 2015-06-11 W. Boschin , M. Girardi , R. Barrena

We report on the use of the NRAO VLA Sky Survey (NVSS) to identify radio galaxie s in eighteen nearby Abell clusters. The listings extend from the cores of the clusters out to radii of 3 Mpc, which corresponds to 1.5 Abell radii and…

天体物理学 · 物理学 2009-11-06 Neal A. Miller , Frazer N. Owen

Radio observations were used to detect the `active' galaxy population within rich clusters of galaxies in a non-biased manner that is not plagued by dust extinction or the K-correction. We present wide-field radio, optical (imaging and…

天体物理学 · 物理学 2009-11-07 G. E. Morrison , F. N. Owen , M. J. Ledlow , W. C. Keel , J. M. Hill , W. Voges , T. Herter

We examine the possible acceleration mechanisms of the relativistic particles responsible for the extended radio emission in Abell 520. We used new LOFAR 145 MHz, archival GMRT 323 MHz and VLA 1.5 GHz data to study the morphological and…

The mechanisms giving rise to diffuse radio emission in galaxy clusters, and in particular their connection with cluster mergers, are still debated. We aim to obtain new insights into the internal dynamics of the cluster Abell 2294,…

宇宙学与河外天体物理 · 物理学 2015-05-18 M. Girardi , W. Boschin , R. Barrena
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