The SAMI Galaxy Survey: understanding observations of large-scale outflows at low redshift with EAGLE simulations

Abstract

This work presents a study of galactic outflows driven by stellar feedback. We extract main sequence disc galaxies with stellar mass 10 9 M /M 5.7 × 10 10 at redshift z = 0 from the highest resolution cosmological simulation of the Evolution and Assembly of GaLaxies and their Environments (EAGLE) set. Synthetic gas rotation velocity and velocity dispersion (σ) maps are created and compared to observations of disc galaxies obtained with the Sydney-AAO Multi-object Integral field spectrograph (SAMI), where σ-values greater than 150 km s −1 are most naturally explained by bipolar outflows powered by starburst activity. We find that the extension of the simulated edge-on (pixelated) velocity dispersion probability distribution depends on stellar mass and star formation rate surface density (Σ SFR ), with low-M /low-Σ SFR galaxies showing a narrow peak at low σ (∼ 30 km s −1 ) and more active, high-M /high-Σ SFR galaxies reaching σ > 150 km s −1 . Although supernova-driven galactic winds in the EAGLE simulations may not entrain enough gas with T < 10 5 K compared to observed galaxies, we find that gas temperature is a good proxy for the presence of outflows. There is a direct correlation between the thermal state of the gas and its state of motion as described by the σ-distribution. The following equivalence relations hold in EAGLE: i) low-σ peak ⇔ disc of the galaxy ⇔ gas with T < 10 5 K; ii) high-σ tail ⇔ galactic winds ⇔ gas with T 10 5 K.

First results from the TNG50 simulation: galactic outflows driven by supernovae and black hole feedback

“…forwarding modeling. Recently, Tescari et al (2018) made a first comparison between EA-GLE 'warm gas' and spatially resolved SAMI/IFU Hα emission to relate gas kinematics to wind signatures. The notable exception is Ceverino et al (2016), who generated synthetic Hα emission line profiles of z ∼ 2 zoom galaxies and correlated their information content with intrinsic outflow properties.…”

Reproducing the Universe: a comparison between the EAGLE simulations and the nearby DustPedia galaxy sample

“…A growing number of studies have analysed the EAGLE simulations and how well they reproduce different observables that were not used for their calibration (e.g. Schaye et al 2015;Crain et al 2015;Furlong et al 2015;Lagos et al 2015;Trayford et al 2015Trayford et al , 2016Furlong et al 2017;Katsianis et al 2017;Tescari et al 2018). Considering the good agreement on the stellar emission only (Fig.…”

An Evolving and Mass-dependent σsSFR–M⋆ Relation for Galaxies

“…The EAGLE reference model and its feedback prescriptions have been calibrated to reproduce key observational constraints, into the present-day stellar mass function of galaxies (Li & White 2009;Baldry et al 2012), the correlation between the black hole and bulge masses (McConnell & Ma 2013) and the dependence of galaxy sizes on mass (Baldry et al 2012) at z ∼ 0. Alongside with these observables the simulation was able to match many other key properties of galaxies in different eras, like molecular hydrogen abundances (Lagos et al 2015), colors and luminosities at z ∼ 0.1 (Trayford et al 2015), supermassive black hole mass function (Rosas-Guevara et al 2016), angular momentum evolution (Lagos et al 2017), atomic hydrogen abundances (Crain et al 2017), sizes (Furlong et al 2017), SFRs (Katsianis et al 2017b), Large-scale outflows (Tescari et al 2018) and ring galaxies (Elagali et al 2018). In addition, Schaller et al (2015) pointed out that there is a good agreement between the normalization and slope of the main sequence present in Chang et al (2015) and the EAGLE reference model.…”