Localized starbursts in dwarf galaxies produced by the impact of low-metallicity cosmic gas clouds

Models of galaxy formation predict that gas accretion from the cosmic web is a primary driver of star formation over cosmic history. Except in very dense environments where galaxy mergers are also important, model galaxies feed from cold streams of gas from the web that penetrate their dark matter h...

Descripción completa

Detalles Bibliográficos
Autores: Sánchez Almeida, J., Elmegreen, B. G., Muñoz-Tuñón, C., Elmegreen, D. M., Pérez Montero, Enrique, Amorín, R., Filho, M. E., Ascasibar, Y., Papaderos, P., Vílchez Medina, José Manuel
Tipo de recurso: artículo
Estado:Versión aceptada para publicación
Fecha de publicación:2015
País:España
Institución:Consejo Superior de Investigaciones Científicas (CSIC)
Repositorio:DIGITAL.CSIC. Repositorio Institucional del CSIC
OAI Identifier:oai:dnet:digitalcsic_::2e57eba4da6486f1c054bb4fb21bf638
Acceso en línea:http://hdl.handle.net/10261/398035
Access Level:acceso abierto
Palabra clave:Galaxies: abundances
Galaxies: dwarf
Galaxies: evolution
Galaxies: formation
Galaxies: structure
Intergalactic medium
id ES_71a1b62c77ea71e2ff11b266dceef971
oai_identifier_str oai:dnet:digitalcsic_::2e57eba4da6486f1c054bb4fb21bf638
network_acronym_str ES
network_name_str España
repository_id_str
spelling Localized starbursts in dwarf galaxies produced by the impact of low-metallicity cosmic gas cloudsSánchez Almeida, J.Elmegreen, B. G.Muñoz-Tuñón, C.Elmegreen, D. M.Pérez Montero, EnriqueAmorín, R.Filho, M. E.Ascasibar, Y.Papaderos, P.Vílchez Medina, José ManuelGalaxies: abundancesGalaxies: dwarfGalaxies: evolutionGalaxies: formationGalaxies: structureIntergalactic mediumModels of galaxy formation predict that gas accretion from the cosmic web is a primary driver of star formation over cosmic history. Except in very dense environments where galaxy mergers are also important, model galaxies feed from cold streams of gas from the web that penetrate their dark matter halos. Although these predictions are unambiguous, the observational support has been indirect so far. Here, we report spectroscopic evidence for this process in extremely metal-poor galaxies (XMPs) of the local universe, taking the form of localized starbursts associated with gas having low metallicity. Detailed abundance analyses based on Gran Telescopio Canarias optical spectra of 10 XMPs show that the galaxy hosts have metallicities around 60% solar, on average, while the large star-forming regions that dominate their integrated light have low metallicities of some 6% solar. Because gas mixes azimuthally in a rotation timescale (a few hundred Myr), the observed metallicity inhomogeneities are only possible if the metal-poor gas fell onto the disk recently. We analyze several possibilities for the origin of the metal-poor gas, favoring the metal-poor gas infall predicted by numerical models. If this interpretation is correct, XMPs trace the cosmic web gas in their surroundings, making them probes to examine its properties. © 2015. The American Astronomical Society. All rights reserved.This work has been partly funded by the Spanish Ministry of Economy and Competitiveness, projects Estallidos AYA2013-47742-C04-02-P and AYA2013-47742-C04-01-P. R.A. acknowledges support from European Commission FP7 SPACE project ASTRODEEP (Ref. No. 312725). P.P. is supported by FCT through the Investigador FCT contract No. IF/01220/2013 and POPH/FSE (EC) by FEDER funding through the program COMPETE, together with the project FCOMP-01-0124-FEDER-029170 (Reference FCT PTDC/FIS-AST/3214/2012), funded by FCT-MEC (PIDDAC) and FEDER (COMPETE).Peer reviewedIOP PublishingEuropean CommissionMinisterio de Economía y Competitividad (España)Consejo Superior de Investigaciones Científicas [https://ror.org/02gfc7t72]202520252015info:eu-repo/semantics/articlehttp://purl.org/coar/resource_type/c_6501Postprintinfo:eu-repo/semantics/acceptedVersionhttp://hdl.handle.net/10261/398035reponame:DIGITAL.CSIC. Repositorio Institucional del CSICinstname:Consejo Superior de Investigaciones Científicas (CSIC)Inglés#PLACEHOLDER_PARENT_METADATA_VALUE##PLACEHOLDER_PARENT_METADATA_VALUE##PLACEHOLDER_PARENT_METADATA_VALUE#info:eu-repo/grantAgreement/MINECO//AYA2013-47742-C4-2-Pinfo:eu-repo/grantAgreement/MINECO//AYA2013-47742-C4-1-Pinfo:eu-repo/grantAgreement/EC/FP7/312725http://dx.doi.org/10.1088/2041-8205/810/2/L15Síinfo:eu-repo/semantics/openAccessoai:dnet:digitalcsic_::2e57eba4da6486f1c054bb4fb21bf6382026-05-22T06:33:51Z
dc.title.none.fl_str_mv Localized starbursts in dwarf galaxies produced by the impact of low-metallicity cosmic gas clouds
title Localized starbursts in dwarf galaxies produced by the impact of low-metallicity cosmic gas clouds
spellingShingle Localized starbursts in dwarf galaxies produced by the impact of low-metallicity cosmic gas clouds
Sánchez Almeida, J.
Galaxies: abundances
Galaxies: dwarf
Galaxies: evolution
Galaxies: formation
Galaxies: structure
Intergalactic medium
title_short Localized starbursts in dwarf galaxies produced by the impact of low-metallicity cosmic gas clouds
title_full Localized starbursts in dwarf galaxies produced by the impact of low-metallicity cosmic gas clouds
title_fullStr Localized starbursts in dwarf galaxies produced by the impact of low-metallicity cosmic gas clouds
title_full_unstemmed Localized starbursts in dwarf galaxies produced by the impact of low-metallicity cosmic gas clouds
title_sort Localized starbursts in dwarf galaxies produced by the impact of low-metallicity cosmic gas clouds
dc.creator.none.fl_str_mv Sánchez Almeida, J.
Elmegreen, B. G.
Muñoz-Tuñón, C.
Elmegreen, D. M.
Pérez Montero, Enrique
Amorín, R.
Filho, M. E.
Ascasibar, Y.
Papaderos, P.
Vílchez Medina, José Manuel
author Sánchez Almeida, J.
author_facet Sánchez Almeida, J.
Elmegreen, B. G.
Muñoz-Tuñón, C.
Elmegreen, D. M.
Pérez Montero, Enrique
Amorín, R.
Filho, M. E.
Ascasibar, Y.
Papaderos, P.
Vílchez Medina, José Manuel
author_role author
author2 Elmegreen, B. G.
Muñoz-Tuñón, C.
Elmegreen, D. M.
Pérez Montero, Enrique
Amorín, R.
Filho, M. E.
Ascasibar, Y.
Papaderos, P.
Vílchez Medina, José Manuel
author2_role author
author
author
author
author
author
author
author
author
dc.contributor.none.fl_str_mv European Commission
Ministerio de Economía y Competitividad (España)
Consejo Superior de Investigaciones Científicas [https://ror.org/02gfc7t72]
dc.subject.none.fl_str_mv Galaxies: abundances
Galaxies: dwarf
Galaxies: evolution
Galaxies: formation
Galaxies: structure
Intergalactic medium
topic Galaxies: abundances
Galaxies: dwarf
Galaxies: evolution
Galaxies: formation
Galaxies: structure
Intergalactic medium
description Models of galaxy formation predict that gas accretion from the cosmic web is a primary driver of star formation over cosmic history. Except in very dense environments where galaxy mergers are also important, model galaxies feed from cold streams of gas from the web that penetrate their dark matter halos. Although these predictions are unambiguous, the observational support has been indirect so far. Here, we report spectroscopic evidence for this process in extremely metal-poor galaxies (XMPs) of the local universe, taking the form of localized starbursts associated with gas having low metallicity. Detailed abundance analyses based on Gran Telescopio Canarias optical spectra of 10 XMPs show that the galaxy hosts have metallicities around 60% solar, on average, while the large star-forming regions that dominate their integrated light have low metallicities of some 6% solar. Because gas mixes azimuthally in a rotation timescale (a few hundred Myr), the observed metallicity inhomogeneities are only possible if the metal-poor gas fell onto the disk recently. We analyze several possibilities for the origin of the metal-poor gas, favoring the metal-poor gas infall predicted by numerical models. If this interpretation is correct, XMPs trace the cosmic web gas in their surroundings, making them probes to examine its properties. © 2015. The American Astronomical Society. All rights reserved.
publishDate 2015
dc.date.none.fl_str_mv 2015
2025
2025
dc.type.none.fl_str_mv info:eu-repo/semantics/article
http://purl.org/coar/resource_type/c_6501
Postprint
info:eu-repo/semantics/acceptedVersion
format article
status_str acceptedVersion
dc.identifier.none.fl_str_mv http://hdl.handle.net/10261/398035
url http://hdl.handle.net/10261/398035
dc.language.none.fl_str_mv Inglés
language_invalid_str_mv Inglés
dc.relation.none.fl_str_mv #PLACEHOLDER_PARENT_METADATA_VALUE#
#PLACEHOLDER_PARENT_METADATA_VALUE#
#PLACEHOLDER_PARENT_METADATA_VALUE#
info:eu-repo/grantAgreement/MINECO//AYA2013-47742-C4-2-P
info:eu-repo/grantAgreement/MINECO//AYA2013-47742-C4-1-P
info:eu-repo/grantAgreement/EC/FP7/312725
http://dx.doi.org/10.1088/2041-8205/810/2/L15
Sí
dc.rights.none.fl_str_mv info:eu-repo/semantics/openAccess
eu_rights_str_mv openAccess
dc.publisher.none.fl_str_mv IOP Publishing
publisher.none.fl_str_mv IOP Publishing
dc.source.none.fl_str_mv reponame:DIGITAL.CSIC. Repositorio Institucional del CSIC
instname:Consejo Superior de Investigaciones Científicas (CSIC)
instname_str Consejo Superior de Investigaciones Científicas (CSIC)
reponame_str DIGITAL.CSIC. Repositorio Institucional del CSIC
collection DIGITAL.CSIC. Repositorio Institucional del CSIC
repository.name.fl_str_mv
repository.mail.fl_str_mv
_version_ 1869410666533617664
score 15.81155

Similares en LA Referencia