Diversity of dwarf galaxy IR-submm emission patterns: CLUES from hydrodynamical simulations

Abstract

Context. The spectral energy distributions (SEDs) of low-mass low-metallicity (dwarf) galaxies are a challenging piece of the puzzle of galaxy formation in the near Universe. These SEDs show some particular features in the submillimeter to far-infrared wavelength range compared to normal larger galaxies that cannot be explained by the current models. Aims. We aim to explain the particular emission features of low-mass low-metallicity galaxies in the IR-submm range, which are: a broadening of the IR peak, which implies a warmer dust component; an excess of emission in the submm (∼500 µm), that causes a flattening of the submm/far-IR slope; and a very low intensity of polycyclic aromatic hydrocarbon emission features. Methods. The SEDs of a sample of 27 simulated dwarf galaxies were calculated using the GRASIL-3D radiative transfer code. This code has the particularity that it separately treats the radiative transfer through dust grains within molecular clouds and within the cirrus, the dense and diffuse components of the gas phase, respectively. The simulated galaxies have stellar masses ranging from 10 6 -10 9 M , and were obtained from a single simulation run within a Local Group environment with initial conditions from the CLUES project.Results. We report a study of the IRAS, Spitzer, and Herschel bands luminosities, and of the star formation rates, dust, and gas (HI and H 2 ) mass contents. We find a satisfactory agreement with observational data, with GRASIL-3D naturally reproducing the specific spectral features mentioned above. Conclusions. We conclude that the GRASIL-3D two-component dust model gives a physical interpretation of the emission of dwarf galaxies: molecular clouds and cirrus represent the warm and cold dust components, respectively, needed to reproduce observational data.

SKIRT 9: Redesigning an advanced dust radiative transfer code to allow kinematics, line transfer and polarization by aligned dust grains

“…Properly comparing the results of these simulations with observations requires a detailed three-dimensional radiation transfer analysis taking into account the effects of dust on the stellar radiation. This calculation is usually performed as a post-processing step starting from a specific snapshot produced by the hydro-dynamical simulation (see, e.g., Calore et al 2015;Bignone et al 2016;Camps et al 2016;Santos-Santos et al 2017;Guidi et al 2018;Lahén et al 2018;Behrens et al 2018;Ma et al 2019;Vogelsberger et al 2019).…”

Numerical simulations of bar formation in the Local Group

“…The CLUES-GASOLINE simulation has been described in more detail by Santos-Santos et al (2016). It has also been analysed in Santos-Santos et al (2017) and Mostoghiu et al (2018).…”

High-resolution synthetic UV-submm images for Milky Way-mass simulated galaxies from the ARTEMIS project

“…In the past decade, many authors have taken this route to generate synthetic observables for cosmological (zoom) simulations (e.g., Jonsson et al 2010;Lanz et al 2014;Granato et al 2015;Bignone et al 2016;Camps et al 2016;Trayford et al 2017;Santos-Santos et al 2017;Lahén et al 2018;Gjergo et al 2018;Barber et al 2018;Narayanan et al 2018;Rodriguez-Gomez et al 2019;Ma et al 2019;Cochrane et al 2019;Liang et al 2019;Vogelsberger et al 2020b;Parsotan et al 2021;Lovell et al 2021;Granato et al 2021). Some also prepare data sets for public use.…”