A Formation Mechanism for “Wrong Way” Radio Relics
Radio relics are typically found to be arc-like regions of synchrotron emission in the outskirts of merging galaxy clusters, bowing out from the cluster center. In most cases they show synchrotron spectra that steepen toward the cluster center, indicating that they are caused by relativistic electro...
| Main Authors: | , , |
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| Format: | Article |
| Language: | English |
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IOP Publishing
2023-01-01
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| Series: | The Astrophysical Journal Letters |
| Subjects: | |
| Online Access: | https://doi.org/10.3847/2041-8213/ad03f7 |
| _version_ | 1797640433774362624 |
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| author | Ludwig M. Böss Ulrich P. Steinwandel Klaus Dolag |
| author_facet | Ludwig M. Böss Ulrich P. Steinwandel Klaus Dolag |
| author_sort | Ludwig M. Böss |
| collection | DOAJ |
| description | Radio relics are typically found to be arc-like regions of synchrotron emission in the outskirts of merging galaxy clusters, bowing out from the cluster center. In most cases they show synchrotron spectra that steepen toward the cluster center, indicating that they are caused by relativistic electrons being accelerated at outward traveling merger shocks. A number of radio relics break with this ideal picture and show morphologies that are bent the opposite way and show spectral index distributions that do not follow expectations from the ideal picture. We propose that these “wrong way” relics can form when an outward traveling shock wave is bent inward by an infalling galaxy cluster or group. We test this in an ultra-high-resolution zoom-in simulation of a massive galaxy cluster with an on-the-fly spectral cosmic-ray model. This allows us to study not only the synchrotron emission at colliding shocks, but also their synchrotron spectra to address the open question of relics with strongly varying spectral indices over the relic surface. |
| first_indexed | 2024-03-11T13:31:34Z |
| format | Article |
| id | doaj.art-c94af5b3ccb5423291f4ed571a1afebc |
| institution | Directory Open Access Journal |
| issn | 2041-8205 |
| language | English |
| last_indexed | 2024-03-11T13:31:34Z |
| publishDate | 2023-01-01 |
| publisher | IOP Publishing |
| record_format | Article |
| series | The Astrophysical Journal Letters |
| spelling | doaj.art-c94af5b3ccb5423291f4ed571a1afebc2023-11-02T18:58:33ZengIOP PublishingThe Astrophysical Journal Letters2041-82052023-01-019572L1610.3847/2041-8213/ad03f7A Formation Mechanism for “Wrong Way” Radio RelicsLudwig M. Böss0https://orcid.org/0000-0003-4690-2774Ulrich P. Steinwandel1https://orcid.org/0000-0001-8867-5026Klaus Dolag2Universitäts-Sternwarte, Fakultät für Physik, Ludwig-Maximilians-Universität München , Scheinerstr. 1, D-81679 München, Germany ; lboess@usm.lmu.de; Excellence Cluster ORIGINS , Boltzmannstr. 2, D-85748 Garching, GermanyCenter for Computational Astrophysics, Flatiron Institute , 162 5th Avenue, New York, NY 10010, USAUniversitäts-Sternwarte, Fakultät für Physik, Ludwig-Maximilians-Universität München , Scheinerstr. 1, D-81679 München, Germany ; lboess@usm.lmu.de; Max Planck Institute for Astrophysics , Karl-Schwarzschildstr. 1, D-85748 Garching, GermanyRadio relics are typically found to be arc-like regions of synchrotron emission in the outskirts of merging galaxy clusters, bowing out from the cluster center. In most cases they show synchrotron spectra that steepen toward the cluster center, indicating that they are caused by relativistic electrons being accelerated at outward traveling merger shocks. A number of radio relics break with this ideal picture and show morphologies that are bent the opposite way and show spectral index distributions that do not follow expectations from the ideal picture. We propose that these “wrong way” relics can form when an outward traveling shock wave is bent inward by an infalling galaxy cluster or group. We test this in an ultra-high-resolution zoom-in simulation of a massive galaxy cluster with an on-the-fly spectral cosmic-ray model. This allows us to study not only the synchrotron emission at colliding shocks, but also their synchrotron spectra to address the open question of relics with strongly varying spectral indices over the relic surface.https://doi.org/10.3847/2041-8213/ad03f7Extragalactic radio sourcesCosmic raysGalaxy clusters |
| spellingShingle | Ludwig M. Böss Ulrich P. Steinwandel Klaus Dolag A Formation Mechanism for “Wrong Way” Radio Relics The Astrophysical Journal Letters Extragalactic radio sources Cosmic rays Galaxy clusters |
| title | A Formation Mechanism for “Wrong Way” Radio Relics |
| title_full | A Formation Mechanism for “Wrong Way” Radio Relics |
| title_fullStr | A Formation Mechanism for “Wrong Way” Radio Relics |
| title_full_unstemmed | A Formation Mechanism for “Wrong Way” Radio Relics |
| title_short | A Formation Mechanism for “Wrong Way” Radio Relics |
| title_sort | formation mechanism for wrong way radio relics |
| topic | Extragalactic radio sources Cosmic rays Galaxy clusters |
| url | https://doi.org/10.3847/2041-8213/ad03f7 |
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