Guardat en:
| Autors principals: | , , , , , , , , , , |
|---|---|
| Format: | Preprint |
| Publicat: |
2024
|
| Matèries: | |
| Accés en línia: | https://arxiv.org/abs/2402.09708 |
| Etiquetes: |
Afegir etiqueta
Sense etiquetes, Sigues el primer a etiquetar aquest registre!
|
| _version_ | 1866929244260532224 |
|---|---|
| author | Shabala, Stanislav Yates-Jones, Patrick Jerrim, Larissa Turner, Ross Krause, Martin Norris, Ray Koribalski, Baerbel Filipovic, Miroslav Rudnick, Larry Power, Chris Crocker, Roland |
| author_facet | Shabala, Stanislav Yates-Jones, Patrick Jerrim, Larissa Turner, Ross Krause, Martin Norris, Ray Koribalski, Baerbel Filipovic, Miroslav Rudnick, Larry Power, Chris Crocker, Roland |
| contents | Odd Radio Circles (ORCs) are a class of low surface brightness, circular objects approximately one arcminute in diameter. ORCs were recently discovered in the Australian Square Kilometre Array Pathfinder (ASKAP) data, and subsequently confirmed with follow-up observations on other instruments, yet their origins remain uncertain. In this paper, we suggest that ORCs could be remnant lobes of powerful radio galaxies, re-energised by the passage of a shock. Using relativistic hydrodynamic simulations with synchrotron emission calculated in post-processing, we show that buoyant evolution of remnant radio lobes is alone too slow to produce the observed ORC morphology. However, the passage of a shock can produce both filled and edge-brightnened ORC-like morphologies for a wide variety of shock and observing orientations. Circular ORCs are predicted to have host galaxies near the geometric centre of the radio emission, consistent with observations of these objects. Significantly offset hosts are possible for elliptical ORCs, potentially causing challenges for accurate host galaxy identification. Observed ORC number counts are broadly consistent with a paradigm in which moderately powerful radio galaxies are their progenitors. |
| format | Preprint |
| id |
arxiv_https___arxiv_org_abs_2402_09708 |
| institution | arXiv |
| publishDate | 2024 |
| record_format | arxiv |
| spellingShingle | Are Odd Radio Circles phoenixes of powerful radio galaxies? Shabala, Stanislav Yates-Jones, Patrick Jerrim, Larissa Turner, Ross Krause, Martin Norris, Ray Koribalski, Baerbel Filipovic, Miroslav Rudnick, Larry Power, Chris Crocker, Roland Astrophysics of Galaxies Cosmology and Nongalactic Astrophysics High Energy Astrophysical Phenomena Odd Radio Circles (ORCs) are a class of low surface brightness, circular objects approximately one arcminute in diameter. ORCs were recently discovered in the Australian Square Kilometre Array Pathfinder (ASKAP) data, and subsequently confirmed with follow-up observations on other instruments, yet their origins remain uncertain. In this paper, we suggest that ORCs could be remnant lobes of powerful radio galaxies, re-energised by the passage of a shock. Using relativistic hydrodynamic simulations with synchrotron emission calculated in post-processing, we show that buoyant evolution of remnant radio lobes is alone too slow to produce the observed ORC morphology. However, the passage of a shock can produce both filled and edge-brightnened ORC-like morphologies for a wide variety of shock and observing orientations. Circular ORCs are predicted to have host galaxies near the geometric centre of the radio emission, consistent with observations of these objects. Significantly offset hosts are possible for elliptical ORCs, potentially causing challenges for accurate host galaxy identification. Observed ORC number counts are broadly consistent with a paradigm in which moderately powerful radio galaxies are their progenitors. |
| title | Are Odd Radio Circles phoenixes of powerful radio galaxies? |
| topic | Astrophysics of Galaxies Cosmology and Nongalactic Astrophysics High Energy Astrophysical Phenomena |
| url | https://arxiv.org/abs/2402.09708 |