The interstellar medium local to HD 10125

Abstract

Based on an HI line and 408- and 1420-MHz radio continuum survey carried out at the Dominion Radio Astrophysical Observatory (DRAO), the environment of the O star HD 10125 has been studied. In addition, complementary radio continuum images, as well as infrared data of the same region have been analysed. An arc-like structure is found in all the radio continuum data. From the 21-cm line data, an HI minimum is found in the velocity range -27 to -32 km s-1. Although HD 10125 is not at the centre of the HI cavity, its eccentric position is consistent with the observed stellar proper motion. The HI cavity and the continuum arc-like structure show an excellent morphological correlation. The radio continuum emission has a spectral index (Sν~να) α= 0.0 +/- 0.1, which establishes the thermal nature of the arc-like feature. The dust temperature obtained from the infrared data is higher in the area where the continuum emission is present. A distance of 3 kpc is derived for the star, the HI cavity and the radio continuum structure. We conclude that all the features we have found are physically related to each other. The O star has enough energetic photons to both ionize the surrounding gas and heat up the dust and, through its powerful wind, also sweep up the HI and HII gas.