The Interstellar Medium Around 41 New Wolf-Rayet Stars in the Inner Galaxy

摘要

Wolf-Rayet (WR) and Of stars are massive stars displaying the most pow-erful stellar winds, both in terms of mass-loss rate and wind velocity (Lozinskaya 1992). At radio frequencies, the CGPS (Taylor et al. 2003) has made it possible to study the interstellar environment of a large number of these stars, all visible from the northern hemisphere. In a recent near-infrared survey of the inner Galactic plane, Shara et al. (2009) identified 41 new WR stars, 15 of type WN and 26 of type WC. We have used the SGPS (Haverkorn et al. 2006) and VGPS (Stil et al. 2006) to search for evidence of large-scale structures around these new WR stars. Using the radio continuum data, we have found six structures of interest. Three of these are previously known supernova remnants (SNR). With the help of the Molonglo survey (Green et al. 1999), we have carried out an analysis of the radio spectrum of these six objects in order to determine the thermal or non-thermal nature of the emission. Of the three new objects, two were bright enough for their spectral index to be determined: one is a new SNR and the other one is a compact shell displaying thermal emission. The 21 cm line data cube is currently under study in an attempt to look for associated neutral hydrogen.