One size fits all: Insights into extrinsic thermal absorption based on the similarity of supernova remnant radio-continuum spectra

Autores
Abadi, Mario Gabriel; Castelletti, Gabriela Marta; Supan, Leonardo; Kassim, Namir E.; Lazio, Joseph W.
Año de publicación
2024
Idioma
inglés
Tipo de recurso
artículo
Estado
versión publicada
Descripción
Typically, integrated radio frequency continuum spectra of supernova remnants (SNRs) exhibit a power-law form due to their synchrotron emission. In numerous cases, these spectra show an exponential turnover, which has long been assumed to be due to thermal free-free absorption in the interstellar medium. We used a compilation of Galactic radio continuum SNR spectra, with and without turnovers, to constrain the distribution of the absorbing ionised gas. We introduce a novel parameterisation of SNR spectra in terms of a characteristic frequency, ν* which depends both on the absorption turnover frequency and the power-law slope. Normalising to v* and to the corresponding flux density, S* we demonstrate that the stacked spectra of our sample reveal a similarity in behavior with low scatter (root mean square, rms, of ~15%), and a unique exponential drop-off that is fully consistent with the predictions of a free-free absorption process. Observed SNRs, whether exhibiting spectral turnovers or not, appear to be spatially well-mixed in the Galaxy without any evident segregation between them. Moreover, their Galactic distribution does not show a correlation with general properties such as heliocentric distance or Galactic longitude, as might have been expected if the absorption were due to a continuous distribution of ionised gas. However, it naturally arises if the absorbers are discretely distributed, as suggested by early low-frequency observations. Modelling based on H II regions tracking Galactic spiral arms successfully reproduces the patchy absorption observed to date. While more extensive statistical datasets should yield more precise spatial models of the absorbing gas distribution, our present conclusion regarding its inhomogeneity will remain robust.
Fil: Abadi, Mario Gabriel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Astronomía Teórica y Experimental. Universidad Nacional de Córdoba. Observatorio Astronómico de Córdoba. Instituto de Astronomía Teórica y Experimental; Argentina
Fil: Castelletti, Gabriela Marta. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Astronomía y Física del Espacio. - Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Astronomía y Física del Espacio; Argentina
Fil: Supan, Leonardo. Consejo Nacional de Investigaciónes Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Astronomía y Física del Espacio. - Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Astronomía y Física del Espacio; Argentina
Fil: Kassim, Namir E.. Naval Research Laboratory; Estados Unidos
Fil: Lazio, Joseph W.. California Institute of Technology; Estados Unidos
Materia
SUPERNOVA REMNANTS
RADIO SPECTRUM
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:11336/256486
Acceder
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network_name_str CONICET Digital (CONICET)
spelling One size fits all: Insights into extrinsic thermal absorption based on the similarity of supernova remnant radio-continuum spectraAbadi, Mario GabrielCastelletti, Gabriela MartaSupan, LeonardoKassim, Namir E.Lazio, Joseph W.SUPERNOVA REMNANTSRADIO SPECTRUMhttps://purl.org/becyt/ford/1.3https://purl.org/becyt/ford/1Typically, integrated radio frequency continuum spectra of supernova remnants (SNRs) exhibit a power-law form due to their synchrotron emission. In numerous cases, these spectra show an exponential turnover, which has long been assumed to be due to thermal free-free absorption in the interstellar medium. We used a compilation of Galactic radio continuum SNR spectra, with and without turnovers, to constrain the distribution of the absorbing ionised gas. We introduce a novel parameterisation of SNR spectra in terms of a characteristic frequency, ν* which depends both on the absorption turnover frequency and the power-law slope. Normalising to v* and to the corresponding flux density, S* we demonstrate that the stacked spectra of our sample reveal a similarity in behavior with low scatter (root mean square, rms, of ~15%), and a unique exponential drop-off that is fully consistent with the predictions of a free-free absorption process. Observed SNRs, whether exhibiting spectral turnovers or not, appear to be spatially well-mixed in the Galaxy without any evident segregation between them. Moreover, their Galactic distribution does not show a correlation with general properties such as heliocentric distance or Galactic longitude, as might have been expected if the absorption were due to a continuous distribution of ionised gas. However, it naturally arises if the absorbers are discretely distributed, as suggested by early low-frequency observations. Modelling based on H II regions tracking Galactic spiral arms successfully reproduces the patchy absorption observed to date. While more extensive statistical datasets should yield more precise spatial models of the absorbing gas distribution, our present conclusion regarding its inhomogeneity will remain robust.Fil: Abadi, Mario Gabriel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Astronomía Teórica y Experimental. Universidad Nacional de Córdoba. Observatorio Astronómico de Córdoba. Instituto de Astronomía Teórica y Experimental; ArgentinaFil: Castelletti, Gabriela Marta. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Astronomía y Física del Espacio. - Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Astronomía y Física del Espacio; ArgentinaFil: Supan, Leonardo. Consejo Nacional de Investigaciónes Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Astronomía y Física del Espacio. - Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Astronomía y Física del Espacio; ArgentinaFil: Kassim, Namir E.. Naval Research Laboratory; Estados UnidosFil: Lazio, Joseph W.. California Institute of Technology; Estados UnidosEDP Sciences2024-04info:eu-repo/semantics/articleinfo:eu-repo/semantics/publishedVersionhttp://purl.org/coar/resource_type/c_6501info:ar-repo/semantics/articuloapplication/pdfapplication/pdfapplication/pdfhttp://hdl.handle.net/11336/256486Abadi, Mario Gabriel; Castelletti, Gabriela Marta; Supan, Leonardo; Kassim, Namir E.; Lazio, Joseph W.; One size fits all: Insights into extrinsic thermal absorption based on the similarity of supernova remnant radio-continuum spectra; EDP Sciences; Astronomy and Astrophysics; 684; A54; 4-2024; 1-100004-6361CONICET DigitalCONICETenginfo:eu-repo/semantics/altIdentifier/doi/10.1051/0004-6361/202346896info:eu-repo/semantics/altIdentifier/url/https://www.aanda.org/articles/aa/full_html/2024/04/aa46896-23/aa46896-23.htmlinfo:eu-repo/semantics/openAccesshttps://creativecommons.org/licenses/by-nc-sa/2.5/ar/reponame:CONICET Digital (CONICET)instname:Consejo Nacional de Investigaciones Científicas y Técnicas2025-10-15T14:40:58Zoai:ri.conicet.gov.ar:11336/256486instacron: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:34982025-10-15 14:40:58.811CONICET Digital (CONICET) - Consejo Nacional de Investigaciones Científicas y Técnicasfalse
dc.title.none.fl_str_mv One size fits all: Insights into extrinsic thermal absorption based on the similarity of supernova remnant radio-continuum spectra
title One size fits all: Insights into extrinsic thermal absorption based on the similarity of supernova remnant radio-continuum spectra
spellingShingle One size fits all: Insights into extrinsic thermal absorption based on the similarity of supernova remnant radio-continuum spectra
Abadi, Mario Gabriel
SUPERNOVA REMNANTS
RADIO SPECTRUM
title_short One size fits all: Insights into extrinsic thermal absorption based on the similarity of supernova remnant radio-continuum spectra
title_full One size fits all: Insights into extrinsic thermal absorption based on the similarity of supernova remnant radio-continuum spectra
title_fullStr One size fits all: Insights into extrinsic thermal absorption based on the similarity of supernova remnant radio-continuum spectra
title_full_unstemmed One size fits all: Insights into extrinsic thermal absorption based on the similarity of supernova remnant radio-continuum spectra
title_sort One size fits all: Insights into extrinsic thermal absorption based on the similarity of supernova remnant radio-continuum spectra
dc.creator.none.fl_str_mv Abadi, Mario Gabriel
Castelletti, Gabriela Marta
Supan, Leonardo
Kassim, Namir E.
Lazio, Joseph W.
author Abadi, Mario Gabriel
author_facet Abadi, Mario Gabriel
Castelletti, Gabriela Marta
Supan, Leonardo
Kassim, Namir E.
Lazio, Joseph W.
author_role author
author2 Castelletti, Gabriela Marta
Supan, Leonardo
Kassim, Namir E.
Lazio, Joseph W.
author2_role author
author
author
author
dc.subject.none.fl_str_mv SUPERNOVA REMNANTS
RADIO SPECTRUM
topic SUPERNOVA REMNANTS
RADIO SPECTRUM
purl_subject.fl_str_mv https://purl.org/becyt/ford/1.3
https://purl.org/becyt/ford/1
dc.description.none.fl_txt_mv Typically, integrated radio frequency continuum spectra of supernova remnants (SNRs) exhibit a power-law form due to their synchrotron emission. In numerous cases, these spectra show an exponential turnover, which has long been assumed to be due to thermal free-free absorption in the interstellar medium. We used a compilation of Galactic radio continuum SNR spectra, with and without turnovers, to constrain the distribution of the absorbing ionised gas. We introduce a novel parameterisation of SNR spectra in terms of a characteristic frequency, ν* which depends both on the absorption turnover frequency and the power-law slope. Normalising to v* and to the corresponding flux density, S* we demonstrate that the stacked spectra of our sample reveal a similarity in behavior with low scatter (root mean square, rms, of ~15%), and a unique exponential drop-off that is fully consistent with the predictions of a free-free absorption process. Observed SNRs, whether exhibiting spectral turnovers or not, appear to be spatially well-mixed in the Galaxy without any evident segregation between them. Moreover, their Galactic distribution does not show a correlation with general properties such as heliocentric distance or Galactic longitude, as might have been expected if the absorption were due to a continuous distribution of ionised gas. However, it naturally arises if the absorbers are discretely distributed, as suggested by early low-frequency observations. Modelling based on H II regions tracking Galactic spiral arms successfully reproduces the patchy absorption observed to date. While more extensive statistical datasets should yield more precise spatial models of the absorbing gas distribution, our present conclusion regarding its inhomogeneity will remain robust.
Fil: Abadi, Mario Gabriel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Astronomía Teórica y Experimental. Universidad Nacional de Córdoba. Observatorio Astronómico de Córdoba. Instituto de Astronomía Teórica y Experimental; Argentina
Fil: Castelletti, Gabriela Marta. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Astronomía y Física del Espacio. - Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Astronomía y Física del Espacio; Argentina
Fil: Supan, Leonardo. Consejo Nacional de Investigaciónes Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Astronomía y Física del Espacio. - Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Astronomía y Física del Espacio; Argentina
Fil: Kassim, Namir E.. Naval Research Laboratory; Estados Unidos
Fil: Lazio, Joseph W.. California Institute of Technology; Estados Unidos
description Typically, integrated radio frequency continuum spectra of supernova remnants (SNRs) exhibit a power-law form due to their synchrotron emission. In numerous cases, these spectra show an exponential turnover, which has long been assumed to be due to thermal free-free absorption in the interstellar medium. We used a compilation of Galactic radio continuum SNR spectra, with and without turnovers, to constrain the distribution of the absorbing ionised gas. We introduce a novel parameterisation of SNR spectra in terms of a characteristic frequency, ν* which depends both on the absorption turnover frequency and the power-law slope. Normalising to v* and to the corresponding flux density, S* we demonstrate that the stacked spectra of our sample reveal a similarity in behavior with low scatter (root mean square, rms, of ~15%), and a unique exponential drop-off that is fully consistent with the predictions of a free-free absorption process. Observed SNRs, whether exhibiting spectral turnovers or not, appear to be spatially well-mixed in the Galaxy without any evident segregation between them. Moreover, their Galactic distribution does not show a correlation with general properties such as heliocentric distance or Galactic longitude, as might have been expected if the absorption were due to a continuous distribution of ionised gas. However, it naturally arises if the absorbers are discretely distributed, as suggested by early low-frequency observations. Modelling based on H II regions tracking Galactic spiral arms successfully reproduces the patchy absorption observed to date. While more extensive statistical datasets should yield more precise spatial models of the absorbing gas distribution, our present conclusion regarding its inhomogeneity will remain robust.
publishDate 2024
dc.date.none.fl_str_mv 2024-04
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/11336/256486
Abadi, Mario Gabriel; Castelletti, Gabriela Marta; Supan, Leonardo; Kassim, Namir E.; Lazio, Joseph W.; One size fits all: Insights into extrinsic thermal absorption based on the similarity of supernova remnant radio-continuum spectra; EDP Sciences; Astronomy and Astrophysics; 684; A54; 4-2024; 1-10
0004-6361
CONICET Digital
CONICET
url http://hdl.handle.net/11336/256486
identifier_str_mv Abadi, Mario Gabriel; Castelletti, Gabriela Marta; Supan, Leonardo; Kassim, Namir E.; Lazio, Joseph W.; One size fits all: Insights into extrinsic thermal absorption based on the similarity of supernova remnant radio-continuum spectra; EDP Sciences; Astronomy and Astrophysics; 684; A54; 4-2024; 1-10
0004-6361
CONICET Digital
CONICET
dc.language.none.fl_str_mv eng
language eng
dc.relation.none.fl_str_mv info:eu-repo/semantics/altIdentifier/doi/10.1051/0004-6361/202346896
info:eu-repo/semantics/altIdentifier/url/https://www.aanda.org/articles/aa/full_html/2024/04/aa46896-23/aa46896-23.html
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
application/pdf
dc.publisher.none.fl_str_mv EDP Sciences
publisher.none.fl_str_mv EDP Sciences
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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