The Lazy Giants: APOGEE Abundances Reveal Low Star Formation Efficiencies in the Magellanic Clouds
Author
dc.contributor.author
Nidever, David L.
Author
dc.contributor.author
Hasselquist, Sten
Author
dc.contributor.author
Hayes, Christian R.
Author
dc.contributor.author
Hawkins, Keith
Author
dc.contributor.author
Povick, Joshua
Author
dc.contributor.author
Majewski, Steven R.
Author
dc.contributor.author
Smith, Verne V.
Author
dc.contributor.author
Anguiano, Borja
Author
dc.contributor.author
Stringfellow, Guy S.
Author
dc.contributor.author
Sobeck, Jennifer S.
Author
dc.contributor.author
Cunha, Katia
Author
dc.contributor.author
Beers, Timothy C.
Author
dc.contributor.author
Bestenlehner, Joachim M.
Author
dc.contributor.author
Cohen, Roger
Author
dc.contributor.author
Garcia-Hernandez, D. A.
Author
dc.contributor.author
Jönsson, Henrik
Author
dc.contributor.author
Nitschelm, Christian
Author
dc.contributor.author
Shetrone, Matthew
Author
dc.contributor.author
Lacerna, Ivan
Author
dc.contributor.author
Allende Prieto, Carlos
Author
dc.contributor.author
Beaton, Rachael L.
Author
dc.contributor.author
Dell’Agli, Flavia
Author
dc.contributor.author
Fernández Trincado, José G.
Author
dc.contributor.author
Feuillet, Diane
Author
dc.contributor.author
Gallart, Carme
Author
dc.contributor.author
Hearty, Fred R.
Author
dc.contributor.author
Holtzman, Jon
Author
dc.contributor.author
Manchado, Arturo
Author
dc.contributor.author
Muñoz Vidal, Ricardo R.
Author
dc.contributor.author
O’Connell, Robert
Author
dc.contributor.author
Rosado, Margarita
Admission date
dc.date.accessioned
2020-07-21T14:50:54Z
Available date
dc.date.available
2020-07-21T14:50:54Z
Publication date
dc.date.issued
2020
Cita de ítem
dc.identifier.citation
The Astrophysical Journal, 895:88 (20pp), 2020 June 1
es_ES
Identifier
dc.identifier.other
10.3847/1538-4357/ab7305
Identifier
dc.identifier.uri
https://repositorio.uchile.cl/handle/2250/176053
Abstract
dc.description.abstract
We report the first APOGEE metallicities and alpha-element abundances measured for 3600 red giant stars spanning a large radial range of both the Large (LMC) and Small Magellanic Clouds, the largest Milky Way (MW) dwarf galaxies. Our sample is an order of magnitude larger than that of previous studies and extends to much larger radial distances. These are the first results presented that make use of the newly installed southern APOGEE instrument on the du Pont telescope at Las Campanas Observatory. Our unbiased sample of the LMC spans a large range in metallicity, from [Fe/H] = -0.2 to very metal-poor stars with [Fe/H] -2.5, the most metal-poor Magellanic Cloud (MC) stars detected to date. The LMC [alpha/Fe]-[Fe/H] distribution is very flat over a large metallicity range but rises by similar to 0.1 dex at -1.0 < [Fe/H] less than or similar to -0.5. We interpret this as a sign of the known recent increase in MC star formation activity and are able to reproduce the pattern with a chemical evolution model that includes a recent "starburst." At the metal-poor end, we capture the increase of [alpha/Fe] with decreasing [Fe/H] and constrain the "alpha-knee" to [Fe/H] less than or similar to -2.2 in both MCs, implying a low star formation efficiency of similar to 0.01 Gyr(-1). The MC knees are more metal-poor than those of less massive MW dwarf galaxies such as Fornax, Sculptor, or Sagittarius. One possible interpretation is that the MCs formed in a lower-density environment than the MW, a hypothesis that is consistent with the paradigm that the MCs fell into the MW's gravitational potential only recently.
es_ES
Patrocinador
dc.description.sponsorship
State Research Agency (AEI) of the Spanish Ministry of Science, Innovation and Universities (MCIU)
European Union (EU)
AYA2017-88254-P
National Science Foundation (NSF)
AST-1801940
Crafoord Foundation
Swedish Research Council
Ruth och Nils-Erik Stenbacks stiftelse
Physics Frontier Center/JINA Center for the Evolution of the Elements (JINA-CEE) - US National Science Foundation
PHY 14-30152
Comisión Nacional de Investigación Científica y Tecnológica (CONICYT)
CONICYT FONDECYT
3180210
1170364
Becas Iberoamerica Investigador 2019, Banco Santander Chile
Comisión Nacional de Investigación Científica y Tecnológica (CONICYT)
CONICYT PIA/BASAL
AFB-170002
Programa de Apoyo a Proyectos de Investigación e Innovación Tecnológica (PAPIIT)
Universidad Nacional Autónoma de México
IN109919
Alfred P. Sloan Foundation
United States Department of Energy (DOE)
Center for High-Performance Computing at the University of Utah