Strongly time-variable ultraviolet metal-line emission from the circum-galactic medium of high-redshift galaxies

Niharika Sravan, Claude André Faucher-Giguère, Freeke van de Voort, Dušan Kereš, Alexander L. Muratov, Philip F. Hopkins, Robert Feldmann, Eliot Quataert, Norman Murray

Research output: Contribution to journalArticlepeer-review

14 Scopus citations


We use cosmological simulations from the Feedback In Realistic Environments project, which implement a comprehensive set of stellar feedback processes, to study ultraviolet (UV) metalline emission from the circum-galactic medium of high-redshift (z = 2-4) galaxies. Our simulations cover the halo mass range Mh ~ 2 × 1011-8.5 × 1012 M at z = 2, representative of Lyman break galaxies. Of the transitions we analyse, the low-ionization CIII (977 Å) and Si III (1207 Å) emission lines are the most luminous, with C IV (1548 Å) and Si IV (1394 Å) also showing interesting spatially extended structures. The more massive haloes are on average more UV-luminous. The UV metal-line emission from galactic haloes in our simulations arises primarily from collisionally ionized gas and is strongly time variable, with peak-to-trough variations of up to ~2 dex. The peaks of UV metal-line luminosity correspond closely to massive and energetic mass outflow events, which follow bursts of star formation and inject sufficient energy into galactic haloes to power the metal-line emission. The strong time variability implies that even some relatively low-mass haloes may be detectable. Conversely, flux-limited samples will be biased towards haloes whose central galaxy has recently experienced a strong burst of star formation. Spatially extended UV metal-line emission around high-redshift galaxies should be detectable by current and upcoming integral field spectrographs such as theMulti Unit Spectroscopic Explorer on the Very Large Telescope and Keck Cosmic Web Imager.

Original languageEnglish (US)
Pages (from-to)120-133
Number of pages14
JournalMonthly Notices of the Royal Astronomical Society
Issue number1
StatePublished - Nov 21 2016
Externally publishedYes

All Science Journal Classification (ASJC) codes

  • Astronomy and Astrophysics
  • Space and Planetary Science


  • Cosmology: theory
  • Galaxies: evolution
  • Galaxies: formation
  • Galaxies: haloes
  • Galaxies: high-redshift
  • Intergalactic medium


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