2016/07/01 by Christopher M. P. Russell, Q. Daniel Wang, Jorge Cuadra
Physics and Astronomy · #Active galactic nucleus #Astronomy #Astrophysical Phenomena and Observations #Astrophysics #Astrophysics and Cosmic Phenomena #Flux (metallurgy) #Galaxy #Meteorology #Outflow #Physics #Pulsars and Gravitational Waves Research #Stars #Supermassive black hole #Thermal #Thermal wind #Wind profile power law #Wind speed #Wolf–Rayet star #astro-ph.HE
paper · pdf · doi:10.1017/s1743921316012308
4 pages, 3 figures, to appear in "Proceedings of IAU Symposium 322: The Multi-Messenger Astrophysics of the Galactic Centre," Steve Longmore, Geoff Bicknell and Roland Crocker, eds
openalex publication_date 2016/07/01 · arxiv created 2016/10/07 · arxiv updated 2017/09/20 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
Abstract The Galactic centre is a hotbed of astrophysical activity, with the injection of wind material from ~30 massive Wolf-Rayet (WR) stars orbiting within 12″ of the super-massive black hole (SMBH) playing an important role. Hydrodynamic simulations of such colliding and accreting winds produce a complex density and temperature structure of cold wind material shocking with the ambient medium, creating a large reservoir of hot, X-ray-emitting gas. This work aims to confront the 3Ms of Chandra X-ray Visionary Program (XVP) observations of this diffuse emission by computing the X-ray emission from these hydrodynamic simulations of the colliding WR winds, amid exploring a variety of SMBH feedback mechanisms. The major success of the model is that it reproduces the spectral shape from the 2″–5″ ring around the SMBH, where most of the stellar wind material that is ultimately captured by Sgr A* is shock-heated and thermalised. This naturally explains that the hot gas comes from colliding WR winds, and that the wind speeds of these stars are in general well constrained. The flux level of these spectra, as well as 12″×12″ images of 4–9 keV, show the X-ray flux is tied to the SMBH feedback strength; stronger feedback clears out more hot gas, thereby decreasing the thermal X-ray emission. The model in which Sgr A* produced an intermediate-strength outflow during the last few centuries best matches the observations to within about 10%, showing SMBH feedback is required to interpret the X-ray emission in this region.