%0 Generic %1 locatelli2023warmhot %A Locatelli, N. %A Ponti, G. %A Zheng, X. %A Merloni, A. %A Becker, W. %A Comparat, J. %A Dennerl, K. %A Freyberg, M. J. %A Sasaki, M. %A Yeung, M. C. H. %D 2023 %K astrophysics %T The warm-hot circumgalactic medium of the Milky Way as seen by eROSITA %U http://arxiv.org/abs/2310.10715 %X The first all-sky maps of the diffuse emission of high ionization lines observed in X-rays by SRG/eROSITA, provide an excellent probe for the study of the warm-hot phase (T~10^6 K) of the circumgalactic medium (CGM) of the Milky Way (MW). In this work we analyse the O VIII line detected in the first eROSITA All-Sky Survey data (eRASS1). We fit a sky map made in a narrow energy bin around this line, with physical emission models embedded in a 3D geometry to constrain the density distribution of the warm-hot gas around our Galaxy, with a focus on mid and high (absolute) Galactic latitudes. By masking out the eROSITA bubbles and other bright extended foreground sources, we find that an oblate geometry of the warm-hot gas (T~0.15-0.17 keV), flattened around the Galactic disk with scale height z_h~1-3 kpc, best describes the eRASS1 O VIII map, with most of the observed emission resulting to be produced within a few kpc from the Sun. The additional presence of a large scale warm-hot spherical halo, while providing a minor contribute to the X-ray emission, accounts for the high O VII absorption column densities detected with XMM-Newton, as well as most of the baryon budget of the CGM of the MW. The eROSITA data carry the largest amount of information and detail of O VIII CGM intensities to date, allowing for a significant reduction of the statistical uncertainties of the inferred physical parameters.

@misc{locatelli2023warmhot, abstract = {The first all-sky maps of the diffuse emission of high ionization lines observed in X-rays by SRG/eROSITA, provide an excellent probe for the study of the warm-hot phase (T~10^6 K) of the circumgalactic medium (CGM) of the Milky Way (MW). In this work we analyse the O VIII line detected in the first eROSITA All-Sky Survey data (eRASS1). We fit a sky map made in a narrow energy bin around this line, with physical emission models embedded in a 3D geometry to constrain the density distribution of the warm-hot gas around our Galaxy, with a focus on mid and high (absolute) Galactic latitudes. By masking out the eROSITA bubbles and other bright extended foreground sources, we find that an oblate geometry of the warm-hot gas (T~0.15-0.17 keV), flattened around the Galactic disk with scale height z_h~1-3 kpc, best describes the eRASS1 O VIII map, with most of the observed emission resulting to be produced within a few kpc from the Sun. The additional presence of a large scale warm-hot spherical halo, while providing a minor contribute to the X-ray emission, accounts for the high O VII absorption column densities detected with XMM-Newton, as well as most of the baryon budget of the CGM of the MW. The eROSITA data carry the largest amount of information and detail of O VIII CGM intensities to date, allowing for a significant reduction of the statistical uncertainties of the inferred physical parameters.}, added-at = {2023-10-18T10:56:29.000+0200}, author = {Locatelli, N. and Ponti, G. and Zheng, X. and Merloni, A. and Becker, W. and Comparat, J. and Dennerl, K. and Freyberg, M. J. and Sasaki, M. and Yeung, M. C. H.}, biburl = {https://www.bibsonomy.org/bibtex/2b97a059078e5759f932f9a1315cd50e7/fboulang}, interhash = {fb06b8d1b0705b1f18f23003a5d4f793}, intrahash = {b97a059078e5759f932f9a1315cd50e7}, keywords = {astrophysics}, note = {cite arxiv:2310.10715Comment: Accepted for publication in Astronomy & Astrophysics}, timestamp = {2023-10-18T10:56:29.000+0200}, title = {The warm-hot circumgalactic medium of the Milky Way as seen by eROSITA}, url = {http://arxiv.org/abs/2310.10715}, year = 2023 }