TY - JOUR
T1 - Strongly time-variable ultraviolet metal-line emission from the circum-galactic medium of high-redshift galaxies
AU - Sravan, Niharika
AU - Faucher-Giguère, Claude André
AU - Voort, Freeke van de
AU - Kereš, Dušan
AU - Muratov, Alexander L.
AU - Hopkins, Philip F.
AU - Feldmann, Robert
AU - Quataert, Eliot
AU - Murray, Norman
N1 - Funding Information:
We are grateful to Alex Richings for assistance with the local source test. The simulations analysed in this paper were run on XSEDE computational resources (allocations TG-AST120025, TGAST130039, and TG-AST140023), on the NASA Pleiades cluster (allocation SMD-14-5189), on the Caltech compute cluster 'Zwicky' (NSFMRI award #PHY-0960291), and on the Quest cluster at Northwestern University. NS and CAFG were supported by NSF through grants AST-1412836 and AST-1517491, by NASA through grant NNX15AB22G, and by Northwestern University funds. DK was supported by NSF grant AST-1412153 and funds from the University of California, San Diego. Support for PFH was provided by an Alfred P. Sloan Research Fellowship, NASA ATP grant NNX14AH35G, and NSF Collaborative Research grant #1411920 and CAREER grant #1455342. RF acknowledges support for this work by NASA through Hubble Fellowship grant HF-51304.01-A awarded by the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Inc., for NASA, under contract NAS 5-26555. EQ was supported by NASA ATP grant 12-APT12-0183, a Simons Investigator award from the Simons Foundation, the David and Lucile Packard Foundation, and the Thomas Alison Schneider Chair in Physics at UC Berkeley.
Publisher Copyright:
© 2015 The Authors. Published by Oxford University Press on behalf of the Royal Astronomical Society.
PY - 2016/11/21
Y1 - 2016/11/21
N2 - 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.
AB - 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.
KW - Cosmology: theory
KW - Galaxies: evolution
KW - Galaxies: formation
KW - Galaxies: haloes
KW - Galaxies: high-redshift
KW - Intergalactic medium
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U2 - 10.1093/mnras/stw1962
DO - 10.1093/mnras/stw1962
M3 - Article
AN - SCOPUS:85015693487
SN - 0035-8711
VL - 463
SP - 120
EP - 133
JO - Monthly Notices of the Royal Astronomical Society
JF - Monthly Notices of the Royal Astronomical Society
IS - 1
ER -