| Autor: |
Carretti, E., Brown, S., Staveley-Smith, L., Malarecki, J. M., Bernardi, G., Gaensler, B. M., Haverkorn, M., Kesteven, M. J., Poppi, S. |
| Předmět: |
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| Zdroj: |
Monthly Notices of the Royal Astronomical Society; Apr2013, Vol. 430 Issue 2, p1414-1422, 9p, 1 Chart, 8 Graphs |
| Abstrakt: |
We have detected a radio bridge of unpolarized synchrotron emission connecting the NW relic of the galaxy cluster Abell 3667 to its central regions. We used data at 2.3 GHz from the S-band Polarization All Sky Survey and at 3.3 GHz from a follow-up observation, both conducted with the Parkes radio telescope. This emission is further aligned with a diffuse X-ray tail, and represents the most compelling evidence for an association between intracluster medium turbulence and diffuse synchrotron emission. This is the first clear detection of a bridge associated both with an outlying cluster relic and X-ray diffuse emission. All the indicators point towards the synchrotron bridge being related to the post-shock turbulent wake trailing the shock front generated by a major merger in a massive cluster. Although predicted by simulations, this is the first time such emission is detected with high significance and clearly associated with the path of a confirmed shock. Although the origin of the relativistic electrons is still unknown, the turbulent re-acceleration model provides a natural explanation for the large-scale emission. The equipartition magnetic field intensity of the bridge is Beq = 2.2 ± 0.3 μG. We further detect diffuse emission coincident with the central regions of the cluster for the first time. [ABSTRACT FROM PUBLISHER] |
| Databáze: |
Complementary Index |
| Externí odkaz: |
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