Digby, Ruth and Navarro, Julio F. and Fattahi, Azadeh and Simpson, Christine M. and Oman, Kyle A. and Gomez, Facundo A. and Frenk, Carlos S and Grand, Robert J. J. and Pakmor, Ruediger (2019) 'The star formation histories of dwarf galaxies in Local Group cosmological simulations.', Monthly notices of the Royal Astronomical Society., 485 (4). pp. 5423-5437.
We use the apostle and Auriga cosmological simulations to study the star formation histories (SFHs) of field and satellite dwarf galaxies. Despite sizeable galaxy-to-galaxy scatter, the SFHs of apostle and Auriga dwarfs exhibit robust average trends with galaxy stellar mass: faint field dwarfs (105 < Mstar/M⊙ < 106) have, on average, steadily declining SFHs, whereas brighter dwarfs (107 < Mstar/M⊙ < 109) show the opposite trend. Intermediate-mass dwarfs have roughly constant SFHs. Satellites exhibit similar average trends, but with substantially suppressed star formation in the most recent ∼5 Gyr, likely as a result of gas loss due to tidal and ram-pressure stripping after entering the haloes of their primaries. These simple mass and environmental trends are in good agreement with the derived SFHs of Local Group (LG) dwarfs whose photometry reaches the oldest main-sequence turn-off. SFHs of galaxies with less deep data show deviations from these trends, but this may be explained, at least in part, by the large galaxy-to-galaxy scatter, the limited sample size, and the large uncertainties of the inferred SFHs. Confirming the predicted mass and environmental trends will require deeper photometric data than currently available, especially for isolated dwarfs.
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|Publisher Web site:||https://doi.org/10.1093/mnras/stz745|
|Publisher statement:||This article has been accepted for publication in Monthly Notices of the Royal Astronomical Society. Published by Oxford University Press on behalf of the Royal Astronomical Society.|
|Date accepted:||11 March 2019|
|Date deposited:||27 June 2019|
|Date of first online publication:||13 March 2019|
|Date first made open access:||27 June 2019|
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