Discovery of Diffuse Radio Emission in a Massive z=1.709 Cool Core Cluster: A Candidate Radio Mini-Halo
Fuente:
arXiv
Gespeichert in:
| Hauptverfasser: | , , , , , , , , , , , , |
|---|---|
| Format: | Preprint |
| Veröffentlicht: |
2025
|
| Schlagworte: | |
| Online-Zugang: | |
| Tags: |
Tag hinzufügen
Keine Tags, Fügen Sie den ersten Tag hinzu!
|
| _version_ | 1866918069662646272 |
|---|---|
| author | Hlavacek-Larrondo, Julie Timmerman, Roland Pfrommer, Christoph Osinga, Erik Tevlin, Larissa Webb, Tracy M. A. Martorella, Natalia Zhang, Xiaoyuan van Weeren, Reinout Choi, Hyunseop Di Gennaro, Gabriella Gendron-Marsolais, Marie-Lou Rhea, Carter |
| author_facet | Hlavacek-Larrondo, Julie Timmerman, Roland Pfrommer, Christoph Osinga, Erik Tevlin, Larissa Webb, Tracy M. A. Martorella, Natalia Zhang, Xiaoyuan van Weeren, Reinout Choi, Hyunseop Di Gennaro, Gabriella Gendron-Marsolais, Marie-Lou Rhea, Carter |
| contents | Clusters of galaxies host spectacular diffuse radio sources, extending over scales from 100 kpc to several Mpcs. These sources, with extremely faint surface brightness ($μ$Jy/arcsec$^2$ level), are not tied to individual galaxies but trace synchrotron emission from large-scale magnetic fields and relativistic particles within the intracluster environment. Here, we report the discovery of a candidate radio mini-halo in SpARCS104922.6+564032.5, the most distant cool-core galaxy cluster identified to date at $z=1.709$, using deep LOFAR 120-168 MHz observations. We show that this emission originates from diffuse cluster-associated processes rather than unresolved AGN or star-forming galaxies. The diffuse radio emission coincides spatially with the X-ray emission of the hot intracluster medium and has a radio power of $P_{\rm 150~MHz}=49.8^{+14.7}_{-11.7} \times10^{24}$ W Hz$^{-1}$, exhibiting striking similarities to low-redshift radio mini-halos. This discovery doubles the redshift of previously known mini-halos, challenging models of inverse Compton losses and indicating the presence of strong magnetic fields, enhanced turbulence in high-redshift clusters, or active hadronic processes that require a cosmic ray-to-thermal energy ratio of 0.07 within 200 kpc, assuming a clumped distribution with spatial correlations among the gas, cosmic rays, and magnetic field that partially compensate for cosmological redshift dimming. It further implies that magnetic fields are efficiently amplified to $\sim$$10~μ$G levels within a Mpc$^3$ volume during the epoch of cluster formation before $z\sim2$. These findings provide critical insights into high-redshift cluster physics and emphasize the transformative potential of next-generation radio surveys, such as those with the SKA and ngVLA, in exploring the early evolution of galaxy clusters. |
| format | Preprint |
| id |
arxiv_https___arxiv_org_abs_2506_19901 |
| institution | arXiv |
| publishDate | 2025 |
| record_format | arxiv |
| spellingShingle | Discovery of Diffuse Radio Emission in a Massive z=1.709 Cool Core Cluster: A Candidate Radio Mini-Halo Hlavacek-Larrondo, Julie Timmerman, Roland Pfrommer, Christoph Osinga, Erik Tevlin, Larissa Webb, Tracy M. A. Martorella, Natalia Zhang, Xiaoyuan van Weeren, Reinout Choi, Hyunseop Di Gennaro, Gabriella Gendron-Marsolais, Marie-Lou Rhea, Carter Cosmology and Nongalactic Astrophysics Astrophysics of Galaxies Clusters of galaxies host spectacular diffuse radio sources, extending over scales from 100 kpc to several Mpcs. These sources, with extremely faint surface brightness ($μ$Jy/arcsec$^2$ level), are not tied to individual galaxies but trace synchrotron emission from large-scale magnetic fields and relativistic particles within the intracluster environment. Here, we report the discovery of a candidate radio mini-halo in SpARCS104922.6+564032.5, the most distant cool-core galaxy cluster identified to date at $z=1.709$, using deep LOFAR 120-168 MHz observations. We show that this emission originates from diffuse cluster-associated processes rather than unresolved AGN or star-forming galaxies. The diffuse radio emission coincides spatially with the X-ray emission of the hot intracluster medium and has a radio power of $P_{\rm 150~MHz}=49.8^{+14.7}_{-11.7} \times10^{24}$ W Hz$^{-1}$, exhibiting striking similarities to low-redshift radio mini-halos. This discovery doubles the redshift of previously known mini-halos, challenging models of inverse Compton losses and indicating the presence of strong magnetic fields, enhanced turbulence in high-redshift clusters, or active hadronic processes that require a cosmic ray-to-thermal energy ratio of 0.07 within 200 kpc, assuming a clumped distribution with spatial correlations among the gas, cosmic rays, and magnetic field that partially compensate for cosmological redshift dimming. It further implies that magnetic fields are efficiently amplified to $\sim$$10~μ$G levels within a Mpc$^3$ volume during the epoch of cluster formation before $z\sim2$. These findings provide critical insights into high-redshift cluster physics and emphasize the transformative potential of next-generation radio surveys, such as those with the SKA and ngVLA, in exploring the early evolution of galaxy clusters. |
| title | Discovery of Diffuse Radio Emission in a Massive z=1.709 Cool Core Cluster: A Candidate Radio Mini-Halo |
| topic | Cosmology and Nongalactic Astrophysics Astrophysics of Galaxies |
| url | https://arxiv.org/abs/2506.19901 |