Photoionization analysis of chemodynamical dwarf galaxies simulations

Autor(en)
B. Melekh, Simone Recchi, Gerhard Hensler, O. Buhajenko
Abstrakt

Photoionization modelling allows us to follow the transport, the emergence, and the absorption of photons taking into account all important processes in nebular plasmas. Such modelling needs the spatial distribution of density, chemical abundances, and temperature, that can be provided by chemodynamical simulations (ChDS) of dwarf galaxies. We perform multicomponent photoionization modelling of the ionized gas using 2D ChDSs of dwarf galaxies. We calculate emissivity maps for important nebular emission lines. Their intensities are used to derive the chemical abundance of oxygen by the so-called Te- and R23-methods. Some disagreements are found between oxygen abundances calculated with these methods and the ones coming from the ChDSs. We investigate the fraction of ionizing radiation emitted in the star-forming region which is able to leak out the galaxy. The time- and direction-averaged escape fraction in our simulation is 0.35-0.4. Finally, we have calculated the total Hαluminosity of our model galaxy using Kennicutt's calibration to derive the star formation rate. This value has been compared to the `true' rate in the ChDSs. The Hα-based star formation rate agrees with the true one only at the beginning of the simulation. Minor deviations arise later on and are due in part to the production of high-energy photons in the warm-hot gas, in part to the leakage of energetic photons out of the galaxy. The effect of artificially introduced thin dense shells (with thicknesses smaller than the ChDSs spatial resolution) is investigated, as well.

Organisation(en)
Institut für Astrophysik
Externe Organisation(en)
Ivan Franko National University of Lviv
Journal
Monthly Notices of the Royal Astronomical Society
Band
450
Seiten
111 - 127
Anzahl der Seiten
17
ISSN
0035-8711
DOI
https://doi.org/10.1093/mnras/stv569
Publikationsdatum
06-2015
Peer-reviewed
Ja
ÖFOS 2012
103003 Astronomie, 103004 Astrophysik
Schlagwörter
ASJC Scopus Sachgebiete
Astronomy and Astrophysics, Space and Planetary Science
Link zum Portal
https://ucrisportal.univie.ac.at/de/publications/photoionization-analysis-of-chemodynamical-dwarf-galaxies-simulations(a6595cf7-fd22-45c6-837e-386f71b3cb34).html