Halo scaling relations and hydrostatic mass bias in the simba simulation from realistic mock X-ray catalogues

Fred Jennings*, Romeel Davé

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

Abstract / Description of output

We present a new end-to-end pipeline for Mock Observations of X-ray Haloes and Analysis (moxha) for hydrodynamic simulations of massive haloes, and use it to investigate X-ray scaling relations and hydrostatic mass bias in the simba cosmological hydrodynamic simulation for haloes with M500 ∼1013-15M·. moxha ties together existing yT-based software packages and adds new functionality to provide an end-to-end pipeline for generating mock X-ray halo data from large-scale or zoom simulation boxes. We compare moxha-derived halo properties in simba to their emission-weighted counterparts, and forecast the systematic mass bias in mock Athena observations. Overall, we find inferred hydrostatic masses are biased low compared to true simba values. For simple mass-weighting, we find (16-84 per cent range), while emission-weighting increases this to. The larger bias versus mass-weighted values we attribute to the spectroscopic and emission-weighted temperatures being biased systematically lower than mass-weighted temperatures. The full moxha pipeline recovers the emission-weighted hydrostatic masses at R500 reasonably well, yielding. moxha-derived halo X-ray scalings are in very good agreement with observed scaling relations, with the inclusion of lower mass groups significantly steepening the LX-M500, M500-TX, and LX-TX relations. This indicates the strong effect the simba feedback model has on low-mass haloes, which strongly evacuates poor groups but still retains enough gas to reproduce observations. We find similar trends for analogous scaling relations measured at R500, as expected for halo-wide gas evacuation.

Original languageEnglish
Pages (from-to)1367-1387
Number of pages21
JournalMonthly Notices of the Royal Astronomical Society
Issue number1
Early online date7 Sept 2023
Publication statusPublished - 1 Nov 2023

Keywords / Materials (for Non-textual outputs)

  • galaxies: clusters: general
  • galaxies: clusters: intracluster medium
  • galaxies: groups: general
  • X-rays: galaxies: clusters


Dive into the research topics of 'Halo scaling relations and hydrostatic mass bias in the simba simulation from realistic mock X-ray catalogues'. Together they form a unique fingerprint.

Cite this