The star formation timescale of elliptical galaxies Fitting [Mg/Fe] and total metallicity simultaneously

Result code in IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F00216208%3A11320%2F19%3A10406205" target="_blank" >RIV/00216208:11320/19:10406205 - isvavai.cz</a>

Result on the web

<a href="https://verso.is.cuni.cz/pub/verso.fpl?fname=obd_publikace_handle&handle=Ynft1m5RfM" target="_blank" >https://verso.is.cuni.cz/pub/verso.fpl?fname=obd_publikace_handle&handle=Ynft1m5RfM</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1051/0004-6361/201936636" target="_blank" >10.1051/0004-6361/201936636</a>

Result language

angličtina

Original language name

The star formation timescale of elliptical galaxies Fitting [Mg/Fe] and total metallicity simultaneously

Original language description

The alpha element to iron peak element ratio, for example [Mg/Fe], is a commonly applied indicator of the galaxy star formation timescale (SFT) since the two groups of elements are mainly produced by different types of supernovae that explode over different timescales. However, it is insufficient to consider only [Mg/Fe] when estimating the SFT. The [Mg/Fe] yield of a stellar population depends on its metallicity. Therefore, it is possible for galaxies with different SFTs and at the same time different total metallicity to have the same [Mg/Fe]. This effect has not been properly taken into consideration in previous studies. In this study, we assume the galaxy-wide stellar initial mass function (gwIMF) to be canonical and invariant. We demonstrate that our computation code reproduces the SFT estimations of previous studies, where only the [Mg/Fe] observational constraint is applied. We then demonstrate that once both metallicity and [Mg/Fe] observations are considered, a more severe &quot;downsizing relation&quot; is required. This means that either low-mass ellipticals have longer SFTs (&gt; 4 Gyr for galaxies with mass below 10(10) M-circle dot) or massive ellipticals have shorter SFTs (approximate to 200 Myr for galaxies more massive than 10(11) M-circle dot) than previously thought. This modification increases the difficulty in reconciling such SFTs with other observational constraints. We show that applying different stellar yield modifications does not relieve this formation timescale problem. The quite unrealistically short SFT required by [Mg/Fe] and total metallicity would be prolonged if a variable stellar gwIMF were assumed. Since a systematically varying gwIMF has been suggested by various observations this could present a natural solution to this problem.

Czech name

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Czech description

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Type

J_imp - Article in a specialist periodical, which is included in the Web of Science database

CEP classification

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OECD FORD branch

10308 - Astronomy (including astrophysics,space science)

Project

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Continuities

I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace

Publication year

2019

Confidentiality

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Name of the periodical

Astronomy &amp; Astrophysics

ISSN

0004-6361

e-ISSN

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Volume of the periodical

632

Issue of the periodical within the volume

prosinec

Country of publishing house

FR - FRANCE

Number of pages

9

Pages from-to

A110

UT code for WoS article

000502330300004

EID of the result in the Scopus database

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