Investigating Particle Acceleration in the Wolf-Rayet Bubble G2.4+1.4
| Autor: | Prajapati, Prachi, Tej, Anandmayee, del Palacio, Santiago, Benaglia, Paula, CH, Ishwara-Chandra, Vig, Sarita, Mandal, Samir, Ghosh, Swarna Kanti |
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| Rok vydání: | 2019 |
| Předmět: | |
| Druh dokumentu: | Working Paper |
| DOI: | 10.3847/2041-8213/ab4992 |
| Popis: | The supersonic winds produced by massive stars carry a large amount of kinetic power. In numerous scenarios such winds have been proven to produce shocks in which relativistic particles are accelerated emitting non-thermal radiation. Here, we report the first detection of non-thermal emission from a single stellar bubble, G2.4+1.4, associated with a WO star. We observed this source with the uGMRT in Band 4 ($550-850$ MHz) and Band 5 ($1050-1450$ MHz). We present intensity and spectral index maps for this source that are consistent with synchrotron emission (average spectral index, $\alpha = -0.83 \pm 0.10$). The fraction of the available kinetic wind power that is converted into cosmic ray acceleration is estimated to be of the order of a few per cent. This finding constitutes an observational breakthrough and gives new insight on the non-thermal physical processes taking place in the environments of isolated massive stars. In particular, our results show that non-runaway isolated massive stars are capable of accelerating relativistic particles and are therefore confirmed as sources of Galactic cosmic rays. Comment: 9 pages, 3 figures, accepted for publication in ApJL |
| Databáze: | arXiv |
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