We investigate the morphology and kinematics of the interstellar medium in
the environs of the open cluster Mrk50, which includes the Wolf-Rayet star
WR157 and a number of early B-type stars. The analysis was performed using
radio continuum images at 408 and 1420 MHz, and HI 21cm line data taken from
the Canadian Galactic Plane Survey, molecular observations of the 12CO (J=1-0)
line at 115 GHz from the Five College Radio Astronomy Observatory and available
mid and far IR observations obtained with the MSX and IRAS satellites,
respectively. This study allowed identification of the radio continuum and
molecular counterpart of the ring nebula SG13, while no neutral atomic
structure was found to be associated. The nebula is also detected in images in
the mid and far infrared, showing the existence of dust well mixed with the
ionized gas. We estimate the main physical parameters of the material linked to
the nebula. The interstellar gas distribution in the environs of Mrk50 is
compatible with a stellar wind bubble created by the mass loss from WR157. The
distribution of young stellar object (YSO) candidates in the region shows that
stellar formation activity may be present in the molecular shell that encircles
the ring nebula.Comment: Accepted for publication in MNRAS, 13 pages, 11 figure
