Multiwavelength study of the H ii region LHA 120-N11 in the Large Magellanic Cloud with eROSITA

Abstract

We stud ied the diffuse X-ray emission around the H ii region LHA 120-N11, which is one of the most active star-forming regions in the Large Magellanic Cloud (LMC). We want to determine the nature of the diffuse X-ray emission and improve our understanding of its origin including related interactions with the cold interstellar medium (ISM). We analyzed the diffuse X-ray emission observed with the extended Roentgen Survey with an Imaging Telescope Array (eROSITA) on the Spectrum-Roentgen-Gamma mission to determine the physical properties of the hot diffuse X-ray emission. Four spectral extraction regions were defined based on the morphology of the X-ray emission. We also studied i and CO data, as well as Halpha line emission in the optical, and compared them with the properties of the diffuse X-ray emission. The X-ray emission in the four regions is well fitted with an absorbed model consisting of thermal plasma models (vapec) yielding temperatures of $kT$ = sim 0.2 keV and $kT$ = 0.8--1.0 keV. The comparison of the X-ray absorption column density and the hydrogen column density shows that the X-ray dark lane located north of N11 is apparently caused by the absorption by H i and CO clouds. By estimating the energy budget of the thermal plasma, we also investigated the heating mechanism of the X-ray emitting plasma. The energy of the diffuse X-ray emission in the superbubble which is a star-forming bubble with a radius of sim 120 pc including OB associations LH9, LH10, LH11, and LH13 can be explained by heating from high-mass stars. In the surrounding regions we find that the energy implied by the X-ray emission suggests that additional heating might have been caused by shocks generated by cloud–cloud collisions.