Searching for evidence of interaction between the Of star HD229196 and the interstellar medium

PINEAULT, S.; ARNAL, M.; CAPPA, C.E.; CICHOWOLSKI, S.; NORMANDEAU, M.; ST-LOUIS, N.

MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY

Año: 2008 vol. 386 p. 1739 - 1749

0035-8711

Massive stars with strong stellar winds are expected to have a huge impact on their interstellar surroundings, an effect which, in a surprisingly large number of cases, is not observed. this work is part of a concerted effort to obtain a better and more homogeneous observational data base with which to test the predictions of theoretical models. Analysis of the interstellar medium around the Of star HD 229196 shows that it coincides with a region of lower radio continuum emission. This suggests that the star has shaped the surrounding ISM via its ionizing flux and stellar wind. However, we find no clear evidence of the star´s action in HI images. The radio continuum morphology and absence of a clear expanding HI shell are consistent with the possibility that the star, which is travelling supersonically at 30 km/s with respect to its local ISM, is creating a weak bow shock. We can not however rule out the possibility that the observed asymmetry is due to an inhomogeneous interstellar density distribution. We used data from the Canadian Galactic Plane Survey  to carry out this study.