The atomic hydrogen shell around S187 region

The shell around S187 is one of the nearby \Hii\ regions (1.4(0.26) pc). The shell has been studied in the \Hi\ line at 8 arcsec resolution, in molecular lines, also in infrared and radio continuum. The shell has a complex kinematical structure, including the expanding quasi-spherical atomic shell, molecular envelope, atomic sub-bubble inside the shell and two dense cores at the different stages of the star formation. The bright radio galaxy in the background gives the possibility of an accurate estimation of the properties of the atomic gas. The total atomic hydrogen mass is 113(34)~Msun, the median spin temperature is ~50K, the shell overall size is about ~2 pc with the wall width 0.2 pc. 

The attached datacube we obtained using the combined GMRT+CGPS data consist of atomic hydrogen 21-cm line. The data imaged at 8 arcsec resolution which is the highest for the Galactic observations to our knowledge.

This work was supported by the Russian Science Foundation under project No. 17-12-01256