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
- Institución
- Consejo Nacional de Investigaciones Científicas y Técnicas
- OAI Identificador
- oai:ri.conicet.gov.ar:11336/256486
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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 Técnicas2025-09-29T09:47:14Zoai: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:34982025-09-29 09:47:14.325CONICET 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 |
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reponame:CONICET Digital (CONICET) instname:Consejo Nacional de Investigaciones Científicas y Técnicas |
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CONICET Digital (CONICET) |
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Consejo Nacional de Investigaciones Científicas y Técnicas |
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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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1844613471852822528 |
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13.070432 |