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The IGIMF and other IMFs in dSphs: : the case of Sagittarius

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contributor authorVincenzo, Fiorenzo
contributor authorMatteucci, Francesca
contributor authorRecchi, Simone
contributor authorCalura, Francesco
contributor authorMcWilliam, Andrew
contributor authorLanfranchi, Gustavo A.
date accessioned2017-08-11T15:06:29Z
date available2017-08-11T15:06:29Z
date issued2015-05-11
identifier citationVincenzo , F , Matteucci , F , Recchi , S , Calura , F , McWilliam , A & Lanfranchi , G A 2015 , ' The IGIMF and other IMFs in dSphs: : the case of Sagittarius ' Monthly Notices of the Royal Astronomical Society , vol 449 , no. 2 , stv357 , pp. 1327-1339 . DOI: 10.1093/mnras/stv357en
identifier issn0035-8711
identifier otherPURE: 11927566
identifier otherPURE UUID: bff38b41-876a-4615-8bfd-4d8bf13fd2a4
identifier otherArXiv:
identifier otherScopus: 84983068765
identifier uri
descriptionThis article has been accepted for publication in Monthly Notices of the Royal Astronomical Society ©: 2015 The Authors. Published by Oxford University Press on behalf of the Royal Astronomical Society. All rights reserveden
description abstractWe have studied the effects of various initial mass functions (IMFs) on the chemical evolution of the Sagittarius dwarf galaxy (Sgr). In particular, we tested the effects of the integrated galactic initial mass function (IGIMF) on various predicted abundance patterns. The IGIMF depends on the star formation rate and metallicity and predicts less massive stars in a regime of low star formation, as it is the case in dwarf spheroidals. We adopted a detailed chemical evolution model following the evolution of α-elements, Fe and Eu, and assuming the currently best set of stellar yields. We also explored different yield prescriptions for the Eu, including production from neutron star mergers. Although the uncertainties still present in the stellar yields and data prevent us from drawing firm conclusions, our results suggest that the IGIMF applied to Sgr predicts lower [α/Fe] ratios than classical IMFs and lower [hydrostatic/explosive] α-element ratios, in qualitative agreement with observations. In our model, the observed high [Eu/O] ratios in Sgr is due to reduced O production, resulting from the IGIMF mass cut-off of the massive oxygen-producing stars, as well as to the Eu yield produced in neutron star mergers, a more promising site than core-collapse supernovae, although many uncertainties are still present in the Eu nucleosynthesis. We find that a model, similar to our previous calculations, based on the late addition of iron from the Type Ia supernova time-delay (necessary to reproduce the shape of [X/Fe] versus [Fe/H] relations) but also including the reduction of massive stars due to the IGIMF, better reproduces the observed abundance ratios in Sgr than models without the IGIMF.en
format extent13en
language isoeng
relation ispartofMonthly Notices of the Royal Astronomical Societyen
subjectstars: abundancesen
subjectgalaxies: abundancesen
subjectgalaxies: dwarfen
subjectgalaxies: evolutionen
subjectgalaxies: formationen
subjectLocal Groupen
titleThe IGIMF and other IMFs in dSphs: : the case of Sagittariusen
contributor institutionSchool of Physics, Astronomy and Mathematicsen
identifier doi
description versionpublishersversionen
description statusPeer revieweden

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