During the first four all-sky surveys eRASS:4 carried out from December 2019 to 2021, the extended Roentgen Survey with an Imaging Telescope Array (eROSITA) on board Spektrum-Roentgen-Gamma (Spektr-RG, SRG) observed the Galactic HII region Carina nebula. We analysed the eRASS:4 data to study the distribution and the spectral properties of the hot interstellar plasma and the bright stellar sources in the Carina nebula. Spectral extraction regions of the diffuse emission were defined based on X-ray spectral morphology and multi-wavelength data. The spectra were fit with a combination of thermal and non-thermal emission models. X-ray bright point sources in the Carina nebula are the colliding wind binary $η$ Car, several O stars, and Wolf-Rayet (WR) stars. We extracted the spectrum of the brightest stellar sources, which can be well fit with a multi-component thermal plasma model. The spectra of the diffuse emission in the brighter parts of the Carina nebula is well reproduced by two thermal models, a lower-temperature component ($\sim$0.2 keV) and a higher-temperature component (0.6 - 0.8 keV). An additional non-thermal component dominates the emission above $\sim$1 keV in the central region around $η$ Car and the other massive stars. Significant orbital variation of the X-ray flux was measured for $η$ Car, WR22 and WR25. $η$ Car requires an additional time-variable thermal component in the spectral model, which is associated to the wind-wind-collision zone. Properties like temperature, pressure, and luminosity of the X-ray emitting plasma in the Carina nebula derived from the eROSITA data are consistent with theoretical calculations of emission from superbubbles. It confirms that the X-ray emission is caused by the hot plasma inside the Carina nebula which has been shocked-heated by the stellar winds of the massive stars, in particular, of $η$ Car.
X-ray panorama of the SS433/W50 complex by SRG/eROSITA
Space Research Institute (IKI)（空间研究所）；Max Planck Institute for Astrophysics（马克斯·普朗克天体物理学研究所）；Universitäts-Sternwarte, Fakultät für Physik, Ludwig-Maximilians-Universität München（慕尼黑大学物理学院大学天文台）
We report the Fermi Large Area Telescope (Fermi-LAT) detection of the $γ$-ray emission toward the massive star forming region of Carina Nebula Complex (CNC). Using the latest source catalog and diffuse background models, we found that the GeV $γ$-ray emission in this region can be resolved into three different components. The GeV $γ$-ray emission from the central point source is considered to originate from the Eta Carina ($η$ Car). We further found the diffuse GeV $γ$-ray emission around the CNC which can be modelled by two Gaussian disks with radii of 0.4°(region A) and 0.75°(region B), resp…
