ASKAP reveals giant radio halos in two merging SPT galaxy clusters
Abstract Early science observations from the Australian Square Kilometre Array Pathfinder (ASKAP) have revealed clear signals of diffuse radio emission associated with two clusters detected by the South Pole Telescope via their Sunyaev Zel’dovich signal: SPT CLJ0553-3342 (MACS J0553.4-3342) and SPT...
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crcambridgeupr:10.1017/pasa.2020.34 2024-05-19T07:48:40+00:00 ASKAP reveals giant radio halos in two merging SPT galaxy clusters Wilber, Amanda G. Johnston-Hollitt, Melanie Duchesne, Stefan W. Tasse, Cyril Akamatsu, Hiroki Intema, Huib Hodgson, Torrance 2020 http://dx.doi.org/10.1017/pasa.2020.34 https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S132335802000034X en eng Cambridge University Press (CUP) https://www.cambridge.org/core/terms Publications of the Astronomical Society of Australia volume 37 ISSN 1323-3580 1448-6083 journal-article 2020 crcambridgeupr https://doi.org/10.1017/pasa.2020.34 2024-04-25T06:51:38Z Abstract Early science observations from the Australian Square Kilometre Array Pathfinder (ASKAP) have revealed clear signals of diffuse radio emission associated with two clusters detected by the South Pole Telescope via their Sunyaev Zel’dovich signal: SPT CLJ0553-3342 (MACS J0553.4-3342) and SPT CLJ0638-5358 (Abell S0592) are both high-mass lensing clusters that have undergone major mergers. To create science-fidelity images of the galaxy clusters, we performed direction-dependent (DD) calibration and imaging on these ASKAP early science observations using state-of-the-art software killMS and DDFacet. Here, we present our DD calibrated ASKAP radio images of both clusters showing unambiguous giant radio halos with largest linear scales of ${\sim}1$ Mpc. The halo in MACS J0553.4-3342 was previously detected with Giant Metrewave Radio Telescope observations at 323 MHz but appears more extended in our ASKAP image. Although there is a shock detected in the thermal X-ray emission of this cluster, we find that the particle number density in the shocked region is too low to allow for the generation of a radio shock. The radio halo in Abell S0592 is a new discovery, and the Southwest border of the halo coincides with a shock detected in X-rays. We discuss the origins of these halos considering both the hadronic and turbulent re-acceleration models and sources of seed electrons. This work gives a positive indication of the potential of ASKAP’s Evolutionary Map of the Universe survey in detecting intracluster medium radio sources. Article in Journal/Newspaper South pole Cambridge University Press Publications of the Astronomical Society of Australia 37 |
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Cambridge University Press |
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English |
description |
Abstract Early science observations from the Australian Square Kilometre Array Pathfinder (ASKAP) have revealed clear signals of diffuse radio emission associated with two clusters detected by the South Pole Telescope via their Sunyaev Zel’dovich signal: SPT CLJ0553-3342 (MACS J0553.4-3342) and SPT CLJ0638-5358 (Abell S0592) are both high-mass lensing clusters that have undergone major mergers. To create science-fidelity images of the galaxy clusters, we performed direction-dependent (DD) calibration and imaging on these ASKAP early science observations using state-of-the-art software killMS and DDFacet. Here, we present our DD calibrated ASKAP radio images of both clusters showing unambiguous giant radio halos with largest linear scales of ${\sim}1$ Mpc. The halo in MACS J0553.4-3342 was previously detected with Giant Metrewave Radio Telescope observations at 323 MHz but appears more extended in our ASKAP image. Although there is a shock detected in the thermal X-ray emission of this cluster, we find that the particle number density in the shocked region is too low to allow for the generation of a radio shock. The radio halo in Abell S0592 is a new discovery, and the Southwest border of the halo coincides with a shock detected in X-rays. We discuss the origins of these halos considering both the hadronic and turbulent re-acceleration models and sources of seed electrons. This work gives a positive indication of the potential of ASKAP’s Evolutionary Map of the Universe survey in detecting intracluster medium radio sources. |
format |
Article in Journal/Newspaper |
author |
Wilber, Amanda G. Johnston-Hollitt, Melanie Duchesne, Stefan W. Tasse, Cyril Akamatsu, Hiroki Intema, Huib Hodgson, Torrance |
spellingShingle |
Wilber, Amanda G. Johnston-Hollitt, Melanie Duchesne, Stefan W. Tasse, Cyril Akamatsu, Hiroki Intema, Huib Hodgson, Torrance ASKAP reveals giant radio halos in two merging SPT galaxy clusters |
author_facet |
Wilber, Amanda G. Johnston-Hollitt, Melanie Duchesne, Stefan W. Tasse, Cyril Akamatsu, Hiroki Intema, Huib Hodgson, Torrance |
author_sort |
Wilber, Amanda G. |
title |
ASKAP reveals giant radio halos in two merging SPT galaxy clusters |
title_short |
ASKAP reveals giant radio halos in two merging SPT galaxy clusters |
title_full |
ASKAP reveals giant radio halos in two merging SPT galaxy clusters |
title_fullStr |
ASKAP reveals giant radio halos in two merging SPT galaxy clusters |
title_full_unstemmed |
ASKAP reveals giant radio halos in two merging SPT galaxy clusters |
title_sort |
askap reveals giant radio halos in two merging spt galaxy clusters |
publisher |
Cambridge University Press (CUP) |
publishDate |
2020 |
url |
http://dx.doi.org/10.1017/pasa.2020.34 https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S132335802000034X |
genre |
South pole |
genre_facet |
South pole |
op_source |
Publications of the Astronomical Society of Australia volume 37 ISSN 1323-3580 1448-6083 |
op_rights |
https://www.cambridge.org/core/terms |
op_doi |
https://doi.org/10.1017/pasa.2020.34 |
container_title |
Publications of the Astronomical Society of Australia |
container_volume |
37 |
_version_ |
1799466980295573504 |