Submillimeter to centimeter excess emission from the Magellanic Clouds. II. On the nature of the excess

Context. Dust emission at sub-millimeter to centimeter wavelengths is often simply the Rayleigh-Jeans tail of dust particles at termal equilibrium and is used as a cold mass tracer in various environments including nearby galaxies. However, well-sampled spectral energy distributions of the nearby, s...

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Author: WILLIAM FRANK WALL
Format: article
Status:Versión aceptada para publicación
Publication Date:2010
Country:México
Institution:Instituto Nacional de Astrofísica, Óptica y Electrónica
Repository:Repositorio Institucional del INAOE
Language:English
OAI Identifier:oai:inaoe.repositorioinstitucional.mx:1009/1566
Online Access:http://inaoe.repositorioinstitucional.mx/jspui/handle/1009/1566
Access Level:Open access
Keyword:info:eu-repo/classification/Inspec/Magellanic Clouds
info:eu-repo/classification/Inspec/Submillimeter:ISM
info:eu-repo/classification/Inspec/Radio continuum: ISM
info:eu-repo/classification/Inspec/ISM:dust
info:eu-repo/classification/Inspec/Galaxies:ISM
info:eu-repo/classification/cti/1
info:eu-repo/classification/cti/21
id MX_4eef9e1c6413d99ed97e7e44f428a15c
oai_identifier_str oai:inaoe.repositorioinstitucional.mx:1009/1566
network_acronym_str MX
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repository_id_str
spelling Submillimeter to centimeter excess emission from the Magellanic Clouds. II. On the nature of the excessWILLIAM FRANK WALLinfo:eu-repo/classification/Inspec/Magellanic Cloudsinfo:eu-repo/classification/Inspec/Submillimeter:ISMinfo:eu-repo/classification/Inspec/Radio continuum: ISMinfo:eu-repo/classification/Inspec/ISM:dustinfo:eu-repo/classification/Inspec/Galaxies:ISMinfo:eu-repo/classification/cti/1info:eu-repo/classification/cti/21info:eu-repo/classification/cti/21Context. Dust emission at sub-millimeter to centimeter wavelengths is often simply the Rayleigh-Jeans tail of dust particles at termal equilibrium and is used as a cold mass tracer in various environments including nearby galaxies. However, well-sampled spectral energy distributions of the nearby, star-forming Magellanic Clouds have a pronounced (sub-)millimeter excess (Israel et al., 2010). Aims. This study attempts to confirm the existence of such amillimeter excess above expected dust, free-free and synchrotron emission and to explore different possibilities for its origin. Methods. We model near-infrared to radio spectral energy distributions of the Magellanic Clouds with dust, free-free and synchrotron emission. A millimeter excess emission is confirmed above these components and its spectral shape and intensity are analysed in light of different scenarios: very cold dust, Cosmic Microwave Background (CMB) fluctuations, a change of the dust spectral index and spinning dust emission. Results. We show that very cold dust or CMB fluctuations are very unlikely explanations for the observed excess in these two galaxies. The excess in the Large Magellanic Cloud can be satisfactorily explained either by a change of the spectral index due to intrinsic properties of amorphous grains, or by spinning dust emission. In the SmallMagellanic Cloud however, due to the importance of the excess, the dust grain model including TLS/DCD effects cannot reproduce the observed emission in a simple way. A posible solution was achieved with spinning dust emission, but many assumptions on the physical state of the interstellar medium had to be made. Conclusions. Further studies, using higher resolution data from Planck and Herschel, are needed to probe the origin of this observed submm-cm excess more definitely. Our study shows that the different possible origins will be best distinguished where the excess is the highest, as is the case in the Small Magellanic Cloud.Astronomy and Astrophysics2010-08-18info:eu-repo/semantics/articleinfo:eu-repo/semantics/acceptedVersionapplication/pdfhttp://inaoe.repositorioinstitucional.mx/jspui/handle/1009/1566reponame:Repositorio Institucional del INAOEinstname:Instituto Nacional de Astrofísica, Óptica y Electrónicainstacron:INAOEengcitation:Bot, C., et al., (2010), Submillimeter to centimeter excess emission from the Magellanic Clouds. II. On the nature of the excess, Astronomy and Astrophysics, Vol. 523(A67):1-8info:eu-repo/semantics/openAccesshttp://creativecommons.org/licenses/by-nc-nd/4.0oai:inaoe.repositorioinstitucional.mx:1009/15662024-08-28T03:22:57Z
dc.title.none.fl_str_mv Submillimeter to centimeter excess emission from the Magellanic Clouds. II. On the nature of the excess
title Submillimeter to centimeter excess emission from the Magellanic Clouds. II. On the nature of the excess
spellingShingle Submillimeter to centimeter excess emission from the Magellanic Clouds. II. On the nature of the excess
WILLIAM FRANK WALL
info:eu-repo/classification/Inspec/Magellanic Clouds
info:eu-repo/classification/Inspec/Submillimeter:ISM
info:eu-repo/classification/Inspec/Radio continuum: ISM
info:eu-repo/classification/Inspec/ISM:dust
info:eu-repo/classification/Inspec/Galaxies:ISM
info:eu-repo/classification/cti/1
info:eu-repo/classification/cti/21
info:eu-repo/classification/cti/21
title_short Submillimeter to centimeter excess emission from the Magellanic Clouds. II. On the nature of the excess
title_full Submillimeter to centimeter excess emission from the Magellanic Clouds. II. On the nature of the excess
title_fullStr Submillimeter to centimeter excess emission from the Magellanic Clouds. II. On the nature of the excess
title_full_unstemmed Submillimeter to centimeter excess emission from the Magellanic Clouds. II. On the nature of the excess
title_sort Submillimeter to centimeter excess emission from the Magellanic Clouds. II. On the nature of the excess
dc.creator.none.fl_str_mv WILLIAM FRANK WALL
author WILLIAM FRANK WALL
author_facet WILLIAM FRANK WALL
author_role author
dc.subject.none.fl_str_mv info:eu-repo/classification/Inspec/Magellanic Clouds
info:eu-repo/classification/Inspec/Submillimeter:ISM
info:eu-repo/classification/Inspec/Radio continuum: ISM
info:eu-repo/classification/Inspec/ISM:dust
info:eu-repo/classification/Inspec/Galaxies:ISM
info:eu-repo/classification/cti/1
info:eu-repo/classification/cti/21
info:eu-repo/classification/cti/21
topic info:eu-repo/classification/Inspec/Magellanic Clouds
info:eu-repo/classification/Inspec/Submillimeter:ISM
info:eu-repo/classification/Inspec/Radio continuum: ISM
info:eu-repo/classification/Inspec/ISM:dust
info:eu-repo/classification/Inspec/Galaxies:ISM
info:eu-repo/classification/cti/1
info:eu-repo/classification/cti/21
info:eu-repo/classification/cti/21
description Context. Dust emission at sub-millimeter to centimeter wavelengths is often simply the Rayleigh-Jeans tail of dust particles at termal equilibrium and is used as a cold mass tracer in various environments including nearby galaxies. However, well-sampled spectral energy distributions of the nearby, star-forming Magellanic Clouds have a pronounced (sub-)millimeter excess (Israel et al., 2010). Aims. This study attempts to confirm the existence of such amillimeter excess above expected dust, free-free and synchrotron emission and to explore different possibilities for its origin. Methods. We model near-infrared to radio spectral energy distributions of the Magellanic Clouds with dust, free-free and synchrotron emission. A millimeter excess emission is confirmed above these components and its spectral shape and intensity are analysed in light of different scenarios: very cold dust, Cosmic Microwave Background (CMB) fluctuations, a change of the dust spectral index and spinning dust emission. Results. We show that very cold dust or CMB fluctuations are very unlikely explanations for the observed excess in these two galaxies. The excess in the Large Magellanic Cloud can be satisfactorily explained either by a change of the spectral index due to intrinsic properties of amorphous grains, or by spinning dust emission. In the SmallMagellanic Cloud however, due to the importance of the excess, the dust grain model including TLS/DCD effects cannot reproduce the observed emission in a simple way. A posible solution was achieved with spinning dust emission, but many assumptions on the physical state of the interstellar medium had to be made. Conclusions. Further studies, using higher resolution data from Planck and Herschel, are needed to probe the origin of this observed submm-cm excess more definitely. Our study shows that the different possible origins will be best distinguished where the excess is the highest, as is the case in the Small Magellanic Cloud.
publishDate 2010
dc.date.none.fl_str_mv 2010-08-18
dc.type.none.fl_str_mv info:eu-repo/semantics/article
info:eu-repo/semantics/acceptedVersion
format article
status_str acceptedVersion
dc.identifier.none.fl_str_mv http://inaoe.repositorioinstitucional.mx/jspui/handle/1009/1566
url http://inaoe.repositorioinstitucional.mx/jspui/handle/1009/1566
dc.language.none.fl_str_mv eng
language eng
dc.relation.none.fl_str_mv citation:Bot, C., et al., (2010), Submillimeter to centimeter excess emission from the Magellanic Clouds. II. On the nature of the excess, Astronomy and Astrophysics, Vol. 523(A67):1-8
dc.rights.none.fl_str_mv info:eu-repo/semantics/openAccess
http://creativecommons.org/licenses/by-nc-nd/4.0
eu_rights_str_mv openAccess
rights_invalid_str_mv http://creativecommons.org/licenses/by-nc-nd/4.0
dc.format.none.fl_str_mv application/pdf
dc.publisher.none.fl_str_mv Astronomy and Astrophysics
publisher.none.fl_str_mv Astronomy and Astrophysics
dc.source.none.fl_str_mv reponame:Repositorio Institucional del INAOE
instname:Instituto Nacional de Astrofísica, Óptica y Electrónica
instacron:INAOE
instname_str Instituto Nacional de Astrofísica, Óptica y Electrónica
instacron_str INAOE
institution INAOE
reponame_str Repositorio Institucional del INAOE
collection Repositorio Institucional del INAOE
repository.name.fl_str_mv
repository.mail.fl_str_mv
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score 15.812429

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