On the collisional disalignment of dust grains in illuminated and shaded regions of IC 63

Autores
Soam, Archana; Anderson, B. G; Acosta Pulido, Jose; Fernandez Lopez, Manuel; Vaillancourt, J. E.; Widicus Weaver, S. L.; Piirola, V.; Gordon, M. S.
Año de publicación
2021
Idioma
inglés
Tipo de recurso
artículo
Estado
versión publicada
Descripción
Interstellar dust grain alignment causes polarization from UV to mm wavelengths, allowing the study of the geometry and strength of the magnetic field. Over the last couple of decades, observations and theory have led to the establishment of the radiative alignment torque mechanism as a leading candidate to explain the effect. With a quantitatively well constrained theory, polarization can be used not only to study the interstellar magnetic field, but also the dust and other environmental parameters. Photodissociation regions, with their intense, anisotropic radiation fields, consequent rapid H2 formation, and high spatial density-contrast provide a rich environment for such studies. Here we discuss an expanded optical, NIR, and mm-wave study of the IC 63 nebula, showing strong H2 formation-enhanced alignment and the first direct empirical evidence for disalignment due to gas-grain collisions using high-resolution HCO+(J = 1-0) observations. We find that a relative amount of polarization is marginally anticorrelated with column density of HCO+. However, separating the lines of sight of optical polarimetry into those behind, or in front of, a dense clump as seen from γ Cas, the distribution separates into two well defined sets, with data corresponding to "shaded" gas having a shallower slope. This is expected if the decrease in polarization is caused by collisions since collisional disalignment rate is proportional to RC∝nT" role="presentation">RC∝nT−−√ . Ratios of the best-fit slopes for the "illuminated" and "shaded" samples of lines of sight agrees, within the uncertainties, with the square root of the two-temperature H2 excitation in the nebula seen by Thi et al.
Fil: Soam, Archana. Sofia Science Center; Estados Unidos
Fil: Anderson, B. G. Sofia Science Center; Estados Unidos
Fil: Acosta Pulido, Jose. Instituto de Astrofisica de Canarias; España
Fil: Fernandez Lopez, Manuel. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas. Instituto Argentino de Radioastronomía. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto Argentino de Radioastronomía; Argentina
Fil: Vaillancourt, J. E.. Lincoln Laboratory; Estados Unidos
Fil: Widicus Weaver, S. L.. Department Of Chemistry; Estados Unidos
Fil: Piirola, V.. University Of Turku; Finlandia
Fil: Gordon, M. S.. Sofia Science Center; Estados Unidos
Materia
Intersterllar dust
Polarimetry
Nivel de accesibilidad
acceso abierto
Condiciones de uso
https://creativecommons.org/licenses/by-nc-sa/2.5/ar/
Repositorio
CONICET Digital (CONICET)
Institución
Consejo Nacional de Investigaciones Científicas y Técnicas
OAI Identificador
oai:ri.conicet.gov.ar:11336/135283
Acceder
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oai_identifier_str oai:ri.conicet.gov.ar:11336/135283
network_acronym_str CONICETDig
repository_id_str 3498
network_name_str CONICET Digital (CONICET)
spelling On the collisional disalignment of dust grains in illuminated and shaded regions of IC 63Soam, ArchanaAnderson, B. GAcosta Pulido, JoseFernandez Lopez, ManuelVaillancourt, J. E.Widicus Weaver, S. L.Piirola, V.Gordon, M. S.Intersterllar dustPolarimetryhttps://purl.org/becyt/ford/1.3https://purl.org/becyt/ford/1Interstellar dust grain alignment causes polarization from UV to mm wavelengths, allowing the study of the geometry and strength of the magnetic field. Over the last couple of decades, observations and theory have led to the establishment of the radiative alignment torque mechanism as a leading candidate to explain the effect. With a quantitatively well constrained theory, polarization can be used not only to study the interstellar magnetic field, but also the dust and other environmental parameters. Photodissociation regions, with their intense, anisotropic radiation fields, consequent rapid H2 formation, and high spatial density-contrast provide a rich environment for such studies. Here we discuss an expanded optical, NIR, and mm-wave study of the IC 63 nebula, showing strong H2 formation-enhanced alignment and the first direct empirical evidence for disalignment due to gas-grain collisions using high-resolution HCO+(J = 1-0) observations. We find that a relative amount of polarization is marginally anticorrelated with column density of HCO+. However, separating the lines of sight of optical polarimetry into those behind, or in front of, a dense clump as seen from γ Cas, the distribution separates into two well defined sets, with data corresponding to "shaded" gas having a shallower slope. This is expected if the decrease in polarization is caused by collisions since collisional disalignment rate is proportional to RC∝nT" role="presentation">RC∝nT−−√ . Ratios of the best-fit slopes for the "illuminated" and "shaded" samples of lines of sight agrees, within the uncertainties, with the square root of the two-temperature H2 excitation in the nebula seen by Thi et al.Fil: Soam, Archana. Sofia Science Center; Estados UnidosFil: Anderson, B. G. Sofia Science Center; Estados UnidosFil: Acosta Pulido, Jose. Instituto de Astrofisica de Canarias; EspañaFil: Fernandez Lopez, Manuel. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas. Instituto Argentino de Radioastronomía. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto Argentino de Radioastronomía; ArgentinaFil: Vaillancourt, J. E.. Lincoln Laboratory; Estados UnidosFil: Widicus Weaver, S. L.. Department Of Chemistry; Estados UnidosFil: Piirola, V.. University Of Turku; FinlandiaFil: Gordon, M. S.. Sofia Science Center; Estados UnidosIOP Publishing2021-02info:eu-repo/semantics/articleinfo:eu-repo/semantics/publishedVersionhttp://purl.org/coar/resource_type/c_6501info:ar-repo/semantics/articuloapplication/pdfapplication/pdfhttp://hdl.handle.net/11336/135283Soam, Archana; Anderson, B. G; Acosta Pulido, Jose; Fernandez Lopez, Manuel; Vaillancourt, J. E.; et al.; On the collisional disalignment of dust grains in illuminated and shaded regions of IC 63; IOP Publishing; Astrophysical Journal; 907; 2; 2-2021; 1-140004-637XCONICET DigitalCONICETenginfo:eu-repo/semantics/altIdentifier/doi/10.3847/1538-4357/abcb8einfo:eu-repo/semantics/altIdentifier/url/https://iopscience.iop.org/article/10.3847/1538-4357/abcb8einfo:eu-repo/semantics/openAccesshttps://creativecommons.org/licenses/by-nc-sa/2.5/ar/reponame:CONICET Digital (CONICET)instname:Consejo Nacional de Investigaciones Científicas y Técnicas2025-10-22T11:56:06Zoai:ri.conicet.gov.ar:11336/135283instacron:CONICETInstitucionalhttp://ri.conicet.gov.ar/Organismo científico-tecnológicoNo correspondehttp://ri.conicet.gov.ar/oai/requestdasensio@conicet.gov.ar; lcarlino@conicet.gov.arArgentinaNo correspondeNo correspondeNo correspondeopendoar:34982025-10-22 11:56:06.35CONICET Digital (CONICET) - Consejo Nacional de Investigaciones Científicas y Técnicasfalse
dc.title.none.fl_str_mv On the collisional disalignment of dust grains in illuminated and shaded regions of IC 63
title On the collisional disalignment of dust grains in illuminated and shaded regions of IC 63
spellingShingle On the collisional disalignment of dust grains in illuminated and shaded regions of IC 63
Soam, Archana
Intersterllar dust
Polarimetry
title_short On the collisional disalignment of dust grains in illuminated and shaded regions of IC 63
title_full On the collisional disalignment of dust grains in illuminated and shaded regions of IC 63
title_fullStr On the collisional disalignment of dust grains in illuminated and shaded regions of IC 63
title_full_unstemmed On the collisional disalignment of dust grains in illuminated and shaded regions of IC 63
title_sort On the collisional disalignment of dust grains in illuminated and shaded regions of IC 63
dc.creator.none.fl_str_mv Soam, Archana
Anderson, B. G
Acosta Pulido, Jose
Fernandez Lopez, Manuel
Vaillancourt, J. E.
Widicus Weaver, S. L.
Piirola, V.
Gordon, M. S.
author Soam, Archana
author_facet Soam, Archana
Anderson, B. G
Acosta Pulido, Jose
Fernandez Lopez, Manuel
Vaillancourt, J. E.
Widicus Weaver, S. L.
Piirola, V.
Gordon, M. S.
author_role author
author2 Anderson, B. G
Acosta Pulido, Jose
Fernandez Lopez, Manuel
Vaillancourt, J. E.
Widicus Weaver, S. L.
Piirola, V.
Gordon, M. S.
author2_role author
author
author
author
author
author
author
dc.subject.none.fl_str_mv Intersterllar dust
Polarimetry
topic Intersterllar dust
Polarimetry
purl_subject.fl_str_mv https://purl.org/becyt/ford/1.3
https://purl.org/becyt/ford/1
dc.description.none.fl_txt_mv Interstellar dust grain alignment causes polarization from UV to mm wavelengths, allowing the study of the geometry and strength of the magnetic field. Over the last couple of decades, observations and theory have led to the establishment of the radiative alignment torque mechanism as a leading candidate to explain the effect. With a quantitatively well constrained theory, polarization can be used not only to study the interstellar magnetic field, but also the dust and other environmental parameters. Photodissociation regions, with their intense, anisotropic radiation fields, consequent rapid H2 formation, and high spatial density-contrast provide a rich environment for such studies. Here we discuss an expanded optical, NIR, and mm-wave study of the IC 63 nebula, showing strong H2 formation-enhanced alignment and the first direct empirical evidence for disalignment due to gas-grain collisions using high-resolution HCO+(J = 1-0) observations. We find that a relative amount of polarization is marginally anticorrelated with column density of HCO+. However, separating the lines of sight of optical polarimetry into those behind, or in front of, a dense clump as seen from γ Cas, the distribution separates into two well defined sets, with data corresponding to "shaded" gas having a shallower slope. This is expected if the decrease in polarization is caused by collisions since collisional disalignment rate is proportional to RC∝nT" role="presentation">RC∝nT−−√ . Ratios of the best-fit slopes for the "illuminated" and "shaded" samples of lines of sight agrees, within the uncertainties, with the square root of the two-temperature H2 excitation in the nebula seen by Thi et al.
Fil: Soam, Archana. Sofia Science Center; Estados Unidos
Fil: Anderson, B. G. Sofia Science Center; Estados Unidos
Fil: Acosta Pulido, Jose. Instituto de Astrofisica de Canarias; España
Fil: Fernandez Lopez, Manuel. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas. Instituto Argentino de Radioastronomía. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto Argentino de Radioastronomía; Argentina
Fil: Vaillancourt, J. E.. Lincoln Laboratory; Estados Unidos
Fil: Widicus Weaver, S. L.. Department Of Chemistry; Estados Unidos
Fil: Piirola, V.. University Of Turku; Finlandia
Fil: Gordon, M. S.. Sofia Science Center; Estados Unidos
description Interstellar dust grain alignment causes polarization from UV to mm wavelengths, allowing the study of the geometry and strength of the magnetic field. Over the last couple of decades, observations and theory have led to the establishment of the radiative alignment torque mechanism as a leading candidate to explain the effect. With a quantitatively well constrained theory, polarization can be used not only to study the interstellar magnetic field, but also the dust and other environmental parameters. Photodissociation regions, with their intense, anisotropic radiation fields, consequent rapid H2 formation, and high spatial density-contrast provide a rich environment for such studies. Here we discuss an expanded optical, NIR, and mm-wave study of the IC 63 nebula, showing strong H2 formation-enhanced alignment and the first direct empirical evidence for disalignment due to gas-grain collisions using high-resolution HCO+(J = 1-0) observations. We find that a relative amount of polarization is marginally anticorrelated with column density of HCO+. However, separating the lines of sight of optical polarimetry into those behind, or in front of, a dense clump as seen from γ Cas, the distribution separates into two well defined sets, with data corresponding to "shaded" gas having a shallower slope. This is expected if the decrease in polarization is caused by collisions since collisional disalignment rate is proportional to RC∝nT" role="presentation">RC∝nT−−√ . Ratios of the best-fit slopes for the "illuminated" and "shaded" samples of lines of sight agrees, within the uncertainties, with the square root of the two-temperature H2 excitation in the nebula seen by Thi et al.
publishDate 2021
dc.date.none.fl_str_mv 2021-02
dc.type.none.fl_str_mv info:eu-repo/semantics/article
info:eu-repo/semantics/publishedVersion
http://purl.org/coar/resource_type/c_6501
info:ar-repo/semantics/articulo
format article
status_str publishedVersion
dc.identifier.none.fl_str_mv http://hdl.handle.net/11336/135283
Soam, Archana; Anderson, B. G; Acosta Pulido, Jose; Fernandez Lopez, Manuel; Vaillancourt, J. E.; et al.; On the collisional disalignment of dust grains in illuminated and shaded regions of IC 63; IOP Publishing; Astrophysical Journal; 907; 2; 2-2021; 1-14
0004-637X
CONICET Digital
CONICET
url http://hdl.handle.net/11336/135283
identifier_str_mv Soam, Archana; Anderson, B. G; Acosta Pulido, Jose; Fernandez Lopez, Manuel; Vaillancourt, J. E.; et al.; On the collisional disalignment of dust grains in illuminated and shaded regions of IC 63; IOP Publishing; Astrophysical Journal; 907; 2; 2-2021; 1-14
0004-637X
CONICET Digital
CONICET
dc.language.none.fl_str_mv eng
language eng
dc.relation.none.fl_str_mv info:eu-repo/semantics/altIdentifier/doi/10.3847/1538-4357/abcb8e
info:eu-repo/semantics/altIdentifier/url/https://iopscience.iop.org/article/10.3847/1538-4357/abcb8e
dc.rights.none.fl_str_mv info:eu-repo/semantics/openAccess
https://creativecommons.org/licenses/by-nc-sa/2.5/ar/
eu_rights_str_mv openAccess
rights_invalid_str_mv https://creativecommons.org/licenses/by-nc-sa/2.5/ar/
dc.format.none.fl_str_mv application/pdf
application/pdf
dc.publisher.none.fl_str_mv IOP Publishing
publisher.none.fl_str_mv IOP Publishing
dc.source.none.fl_str_mv reponame:CONICET Digital (CONICET)
instname:Consejo Nacional de Investigaciones Científicas y Técnicas
reponame_str CONICET Digital (CONICET)
collection CONICET Digital (CONICET)
instname_str Consejo Nacional de Investigaciones Científicas y Técnicas
repository.name.fl_str_mv CONICET Digital (CONICET) - Consejo Nacional de Investigaciones Científicas y Técnicas
repository.mail.fl_str_mv dasensio@conicet.gov.ar; lcarlino@conicet.gov.ar
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score 12.982451

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