Edinburgh Research Explorer

Simulation of soft X-ray emission lines from the Missing Baryons

Research output: Contribution to journalArticle

  • Taotao Fang
  • Rupert A.C. Croft
  • Wilton T. Sanders
  • John Houck
  • Romeel Davé
  • Neal Katz
  • David H. Weinberg
  • Lars Hernquist

Related Edinburgh Organisations

Open Access permissions


Original languageEnglish
Pages (from-to)612-626
Number of pages15
JournalAstrophysical Journal
Issue number2 I
Publication statusPublished - 20 Apr 2005


We study the soft X-ray emission (0.1-1 keV) from the warm-hot intergalactic medium (WHIM) in a hydrodynamic simulation of a cold dark matter universe. Our main goal is to investigate how such emission can be explored with a combination of imaging and spectroscopy and to motivate future X-ray missions. We first present high-resolution images of the X-ray emission in several energy bands in which emission from different ion species dominates. We pick three different areas to study the high-resolution spectra of X-rays from the WHIM: (1) a galaxy group, (2) a filament, and (3) an underluminous region. By taking into account the background X-ray emission from AGNs and foreground emission from the Galaxy, we compute composite X-ray spectra of the selected regions. We briefly investigate angular clustering of the soft X-ray emission, finding a strong signal. Most interestingly, the combination of high spectral resolution and angular information allows us to map the emission from the WHIM in three dimensions. We cross-correlate the positions of galaxies in the simulation with this redshift map of emission and detect the presence of six different ion species (Ne IX, Fe XVII, O VII, O VII, N VII, and C VI) in the large-scale structure traced by the galaxies. Finally, we show how such emission can be detected and studied with future X-ray satellites, with particular attention to a proposed mission, the Missing Baryon Explorer (MBE). We present simulated observations of the WHIM gas with MBE.

    Research areas

  • Cosmology: theory, Diffuse radiation, Intergalactic medium, Large-scale structure of universe, X-rays: Diffuse background

ID: 145371703