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arXiv · 1602.07805

X-ray Observations of Bow Shocks around Runaway O Stars. The case of $ζ$ Oph and BD+43$^{\circ}$3654

J. A. Toalá·L. M. Oskinova·A. González-Galán·M. A. Guerrero·R. Ignace·M. Pohl
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Abstract

Non-thermal radiation has been predicted within bow shocks around runaway stars by recent theoretical works. We present X-ray observations towards the runaway stars $ζ$ Oph (Chandra and Suzaku) and BD+43$^{\circ}$3654 (XMM-Newton) to search for the presence of non-thermal X-ray emission. We found no evidence of non-thermal emission spatially coincident with the bow shocks, nonetheless, diffuse emission is detected in the vicinity of $ζ$ Oph. After a careful analysis of its spectral characteristics we conclude that this emission has a thermal nature with a plasma temperature of $T \approx 2 \times10^{6}$ K. The cometary shape of this emission seems to be in line with recent predictions of radiation-hydrodynamic models of runaway stars. The case of BD+43$^{\circ}$3654 is puzzling as non-thermal emission has been reported in a previous work for this source.

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J. A. Toalá, L. M. Oskinova, A. González-Galán, M. A. Guerrero, R. Ignace, M. Pohl. 2016-02-26. X-ray Observations of Bow Shocks around Runaway O Stars. The case of $ζ$ Oph and BD+43$^{\circ}$3654. https://doi.org/10.3847/0004-637x%2F821%2F2%2F79

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