Unveiling the Sources of X-Ray Luminosity in DESI Galaxy Groups: Insights from the SRG/eROSITA All-sky Survey
Year: 2026
Type: article
Abstract: We use the first eROSITA all-sky survey to investigate the contributions of active galactic nuclei (AGN) and extended gas to the total X-ray luminosity ( L X ) of galaxy groups with different halo masses ( M h ) at different redshifts. The presence of AGN in their central galaxies is identified using multiwavelength catalogs, including the X-ray counterparts, the ASKAP radio catalog, and the DESI spectroscopic measurements. We apply the stacking method to obtain sufficient statistics for the X-ray surface brightness profile and the L X for groups with different central AGN properties. We find that the X-ray groups exhibit the highest L X , followed by groups with QSO, radio, Baldwin–Phillips–Terlevich AGN, and non-AGN centrals. Moreover, the L X of the M h ≲ 10 13 h −1 M ⊙ groups is dominated by the central AGN, while the X-ray emission from extended gas tends to be more prominent in the M h ≳ 10 13 h −1 M ⊙ groups. In groups where the AGN play a major role in X-ray emission, the contribution from extended gas is minor, resulting in significant uncertainties concerning the extended X-ray emission. When the subset containing the X-ray-detected counterparts is excluded, the extended gas component becomes easier to obtain. A correlation has been identified between the X-ray luminosity of the central AGN and extended gas. However, once we account for the positional offset, their correlation becomes less prominent. Currently, the results are not conclusive enough to confirm whether there is a connection between the AGN feedback and extended gas. However, they provide a new perspective on the feedback processes in the history of group assembly.
Source: The Astrophysical Journal
Institution: Max Planck Institute for Extraterrestrial Physics
Language: English
Subfield: Astronomy and Astrophysics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: gold
Estimated APC paid: $4,499
Funders: National Science Foundation, U.S. Department of Energy, National Aeronautics and Space Administration, Gordon and Betty Moore Foundation, California Institute of Technology, Natural Science Foundation of Shanghai, Chinese Academy of Sciences, China Postdoctoral Science Foundation, Consejo Nacional de Ciencia y Tecnología, Ministerio de Ciencia e Innovación, Shanghai Jiao Tong University, Commissariat à l'Énergie Atomique et aux Énergies Alternatives, Higher Education Discipline Innovation Project, Office of Science, Jet Propulsion Laboratory, Science and Technology Facilities Council, Fundamental Research Funds for the Central Universities, Division of Astronomical Sciences, High Energy Physics, Lawrence Berkeley National Laboratory
OpenAlex ID: W7124429274