High significance detection at 4.8 GHz of the radio halo in the Coma galaxy cluster with the Sardinia Radio Telescope
Fuente:
arXiv
Gespeichert in:
| Hauptverfasser: | , , , , , , |
|---|---|
| Format: | Preprint |
| Veröffentlicht: |
2026
|
| Schlagworte: | |
| Online-Zugang: | |
| Tags: |
Tag hinzufügen
Keine Tags, Fügen Sie den ersten Tag hinzu!
|
| _version_ | 1866918396862398464 |
|---|---|
| author | Marchegiani, P. Murgia, M. Loi, F. Vacca, V. Govoni, F. Cocchi, S. Gandossi, F. |
| author_facet | Marchegiani, P. Murgia, M. Loi, F. Vacca, V. Govoni, F. Cocchi, S. Gandossi, F. |
| contents | We present the results of observations of the radio halo in the Coma galaxy cluster at 4.8 GHz performed with the Sardinia Radio Telescope. The radio halo in this cluster is detected for the first time at this frequency with a statistical significance higher than $3σ$. After the removal of the Radio Frequency Interference and of the discrete sources contribution, and after the correction for the Sunyaev-Zel'dovich effect, we estimate a flux density of $61\pm11$ mJy, higher than the value previously reported in literature at this frequency. By using the value we obtained, it is possible to estimate an integrated spectral index between 4.8 and 6.6 GHz of $α\sim1.17$, where $F(ν)\propto ν^{-α}$, indicating a possible higher-frequency slowdown of the spectral steepening observed between 1.4 and 4.8 GHz. Such a spectral behavior is compatible with turbulent re-acceleration if the seed electrons have a spectrum extending up to high energies, as in the case of continuous injection by hadronic interactions or dark matter annihilation. We also report the detection at 4.8 GHz of a polarized spot inside the halo, without an evident counterpart, already detected at 6.6 GHz. |
| format | Preprint |
| id |
arxiv_https___arxiv_org_abs_2602_16364 |
| institution | arXiv |
| publishDate | 2026 |
| record_format | arxiv |
| spellingShingle | High significance detection at 4.8 GHz of the radio halo in the Coma galaxy cluster with the Sardinia Radio Telescope Marchegiani, P. Murgia, M. Loi, F. Vacca, V. Govoni, F. Cocchi, S. Gandossi, F. Cosmology and Nongalactic Astrophysics We present the results of observations of the radio halo in the Coma galaxy cluster at 4.8 GHz performed with the Sardinia Radio Telescope. The radio halo in this cluster is detected for the first time at this frequency with a statistical significance higher than $3σ$. After the removal of the Radio Frequency Interference and of the discrete sources contribution, and after the correction for the Sunyaev-Zel'dovich effect, we estimate a flux density of $61\pm11$ mJy, higher than the value previously reported in literature at this frequency. By using the value we obtained, it is possible to estimate an integrated spectral index between 4.8 and 6.6 GHz of $α\sim1.17$, where $F(ν)\propto ν^{-α}$, indicating a possible higher-frequency slowdown of the spectral steepening observed between 1.4 and 4.8 GHz. Such a spectral behavior is compatible with turbulent re-acceleration if the seed electrons have a spectrum extending up to high energies, as in the case of continuous injection by hadronic interactions or dark matter annihilation. We also report the detection at 4.8 GHz of a polarized spot inside the halo, without an evident counterpart, already detected at 6.6 GHz. |
| title | High significance detection at 4.8 GHz of the radio halo in the Coma galaxy cluster with the Sardinia Radio Telescope |
| topic | Cosmology and Nongalactic Astrophysics |
| url | https://arxiv.org/abs/2602.16364 |