Study of the extreme gamma-ray emission from Supernova Remnants and the Crab Pulsar
In our Galaxy, supernova remnants and pulsars are the two most numerous populations of non-thermal objects. The goal of this thesis is to study the extreme gamma-ray emission from these two astrophysical objects with Fermi -LAT and MAGIC. In particular, supernova remnants Cassiopeia A and SNR G24.7+...
| Autor: | |
|---|---|
| Tipo de recurso: | tesis doctoral |
| Estado: | Versión publicada |
| Fecha de publicación: | 2018 |
| País: | España |
| Institución: | CBUC, CESCA |
| Repositorio: | TDR. Tesis Doctorales en Red |
| OAI Identifier: | oai:www.tdx.cat:10803/663414 |
| Acceso en línea: | http://hdl.handle.net/10803/663414 |
| Access Level: | acceso abierto |
| Palabra clave: | Astrofísica Astrophysics Raigs còsmics Rayos cósmicos Cosmic rays Raigs gamma Rayos gamma Gamma rays Púlsars Pulsares Pulsars Supernoves Supernovas Supernovae Ciències Experimentals i Matemàtiques 52 |
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Study of the extreme gamma-ray emission from Supernova Remnants and the Crab Pulsar |
| title |
Study of the extreme gamma-ray emission from Supernova Remnants and the Crab Pulsar |
| spellingShingle |
Study of the extreme gamma-ray emission from Supernova Remnants and the Crab Pulsar Galindo Fernández, Daniel Astrofísica Astrophysics Raigs còsmics Rayos cósmicos Cosmic rays Raigs gamma Rayos gamma Gamma rays Púlsars Pulsares Pulsars Supernoves Supernovas Supernovae Ciències Experimentals i Matemàtiques 52 |
| title_short |
Study of the extreme gamma-ray emission from Supernova Remnants and the Crab Pulsar |
| title_full |
Study of the extreme gamma-ray emission from Supernova Remnants and the Crab Pulsar |
| title_fullStr |
Study of the extreme gamma-ray emission from Supernova Remnants and the Crab Pulsar |
| title_full_unstemmed |
Study of the extreme gamma-ray emission from Supernova Remnants and the Crab Pulsar |
| title_sort |
Study of the extreme gamma-ray emission from Supernova Remnants and the Crab Pulsar |
| dc.creator.none.fl_str_mv |
Galindo Fernández, Daniel |
| author |
Galindo Fernández, Daniel |
| author_facet |
Galindo Fernández, Daniel |
| author_role |
author |
| dc.contributor.none.fl_str_mv |
Paredes i Poy, Josep Maria Zanin, Roberta Manrique Oliva, Alberto Universitat de Barcelona. Departament de Física Quàntica i Astrofísica |
| dc.subject.none.fl_str_mv |
Astrofísica Astrophysics Raigs còsmics Rayos cósmicos Cosmic rays Raigs gamma Rayos gamma Gamma rays Púlsars Pulsares Pulsars Supernoves Supernovas Supernovae Ciències Experimentals i Matemàtiques 52 |
| topic |
Astrofísica Astrophysics Raigs còsmics Rayos cósmicos Cosmic rays Raigs gamma Rayos gamma Gamma rays Púlsars Pulsares Pulsars Supernoves Supernovas Supernovae Ciències Experimentals i Matemàtiques 52 |
| description |
In our Galaxy, supernova remnants and pulsars are the two most numerous populations of non-thermal objects. The goal of this thesis is to study the extreme gamma-ray emission from these two astrophysical objects with Fermi -LAT and MAGIC. In particular, supernova remnants Cassiopeia A and SNR G24.7+0.6 and the Crab pulsar. Cassiopeia A, one of the historical supernova remnants and the prime candidate of its class to be a PeVatron accelerator, has been discarded as so since we provided the first measurement of a turn-off in the gamma-ray spectrum at 3 TeV, implying the emission observed is produced by the decay of neutral pions, produced in proton- proton interactions of a parent population of accelerated protons with an energy cut-off at about 10TeV. Such a maximum energy of accelerated cosmic rays in Cassiopeia A falls short to explain the high energy end ( PeV) of the Galactic cosmic ray spectrum. Considering that Cassiopeia A was the main PeVatron candidate, the results obtained in this work challenge the existence of supernova remnants as galactic Pevatrons and therefore the popular conviction that supernova remnants are the main source of Galactic cosmic ray up to the knee. In the case of SNR G24.7+0.6, the remnant is evolving in a dense medium and might be interacting with the CO-rich surrounding. The observations performed allowed us to detect for the first time the counterpart of the radio emission, MAGIC J1835–069, from 60MeV up to 5TeV. This very high energy emission results from proton-proton interactions between the runaway protons from the supernova remnant and a nearby molecular cloud. These observations of the field of view of SNR G24.7+0.6, also resulted in the detection of another new source, MAGIC J1837–073, that is likely to be associated with a stellar cluster as suggested by its localization in a region rich in molecular content and crowded of sources. The total energy obtained in accelerated protons can be explained assuming a quasi-continuous injection of cosmic rays during the cluster lifetime. The second part of this thesis is focused on the study and understanding of the Crab pulsar, the young and most energetic pulsar in our galaxy. Observations carried out with MAGIC resulted in the first ever detection of very energetic pulsed emission from a pulsar, reaching up to about 1.5 TeV. Moreover, the light curve of the Crab above 400 GeV shows two peaks synchronized with those measured at lower energies. Such extremely energetic pulsed emission has to be produced by electrons with very high Lorentz factor scattering low energy photons in the vicinity of the light cylinder, either inside or outside of it. Currently, none of the postulated models is yet capable of reproducing at the same time the light curve and the spectral shape for both peaks above 400 GeV. |
| publishDate |
2018 |
| dc.date.none.fl_str_mv |
2018 2018 2019 |
| dc.type.none.fl_str_mv |
info:eu-repo/semantics/doctoralThesis info:eu-repo/semantics/publishedVersion |
| format |
doctoralThesis |
| status_str |
publishedVersion |
| dc.identifier.none.fl_str_mv |
http://hdl.handle.net/10803/663414 |
| url |
http://hdl.handle.net/10803/663414 |
| dc.language.none.fl_str_mv |
Inglés |
| language_invalid_str_mv |
Inglés |
| dc.rights.none.fl_str_mv |
http://creativecommons.org/licenses/by-nc-sa/4.0/ info:eu-repo/semantics/openAccess |
| rights_invalid_str_mv |
http://creativecommons.org/licenses/by-nc-sa/4.0/ |
| eu_rights_str_mv |
openAccess |
| dc.format.none.fl_str_mv |
175 p. application/pdf application/pdf |
| dc.publisher.none.fl_str_mv |
Universitat de Barcelona |
| publisher.none.fl_str_mv |
Universitat de Barcelona |
| dc.source.none.fl_str_mv |
TDX (Tesis Doctorals en Xarxa) reponame:TDR. Tesis Doctorales en Red instname:CBUC, CESCA |
| instname_str |
CBUC, CESCA |
| reponame_str |
TDR. Tesis Doctorales en Red |
| collection |
TDR. Tesis Doctorales en Red |
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|
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|
| _version_ |
1869407683677782016 |
| spelling |
Study of the extreme gamma-ray emission from Supernova Remnants and the Crab PulsarGalindo Fernández, DanielAstrofísicaAstrophysicsRaigs còsmicsRayos cósmicosCosmic raysRaigs gammaRayos gammaGamma raysPúlsarsPulsaresPulsarsSupernovesSupernovasSupernovaeCiències Experimentals i Matemàtiques52In our Galaxy, supernova remnants and pulsars are the two most numerous populations of non-thermal objects. The goal of this thesis is to study the extreme gamma-ray emission from these two astrophysical objects with Fermi -LAT and MAGIC. In particular, supernova remnants Cassiopeia A and SNR G24.7+0.6 and the Crab pulsar. Cassiopeia A, one of the historical supernova remnants and the prime candidate of its class to be a PeVatron accelerator, has been discarded as so since we provided the first measurement of a turn-off in the gamma-ray spectrum at 3 TeV, implying the emission observed is produced by the decay of neutral pions, produced in proton- proton interactions of a parent population of accelerated protons with an energy cut-off at about 10TeV. Such a maximum energy of accelerated cosmic rays in Cassiopeia A falls short to explain the high energy end ( PeV) of the Galactic cosmic ray spectrum. Considering that Cassiopeia A was the main PeVatron candidate, the results obtained in this work challenge the existence of supernova remnants as galactic Pevatrons and therefore the popular conviction that supernova remnants are the main source of Galactic cosmic ray up to the knee. In the case of SNR G24.7+0.6, the remnant is evolving in a dense medium and might be interacting with the CO-rich surrounding. The observations performed allowed us to detect for the first time the counterpart of the radio emission, MAGIC J1835–069, from 60MeV up to 5TeV. This very high energy emission results from proton-proton interactions between the runaway protons from the supernova remnant and a nearby molecular cloud. These observations of the field of view of SNR G24.7+0.6, also resulted in the detection of another new source, MAGIC J1837–073, that is likely to be associated with a stellar cluster as suggested by its localization in a region rich in molecular content and crowded of sources. The total energy obtained in accelerated protons can be explained assuming a quasi-continuous injection of cosmic rays during the cluster lifetime. The second part of this thesis is focused on the study and understanding of the Crab pulsar, the young and most energetic pulsar in our galaxy. Observations carried out with MAGIC resulted in the first ever detection of very energetic pulsed emission from a pulsar, reaching up to about 1.5 TeV. Moreover, the light curve of the Crab above 400 GeV shows two peaks synchronized with those measured at lower energies. Such extremely energetic pulsed emission has to be produced by electrons with very high Lorentz factor scattering low energy photons in the vicinity of the light cylinder, either inside or outside of it. Currently, none of the postulated models is yet capable of reproducing at the same time the light curve and the spectral shape for both peaks above 400 GeV.Esta tesis tiene como objetivo el estudio de la emisión extrema de rayos gamma proveniente de remanentes de supernova y el pulsar del Cangrejo. Dos remanentes de supernova han sido observados tanto con Fermi, como con MAGIC; Cassiopeia A y SNR G24.7+0.6. Cassiopeia A, el principal candidato de su clase a revelarse como PeVatrón, ha sido descartado como tal, al haberse detectado un corte en el espectro de rayos gamma en torno a 3 TeV, lo cual implica que, la emisión observada es producida por el de- caimiento de piones neutros, originados en colisiones protón-protón por una población de protones que presenta un corte exponencial en su espectro en torno a una energía de 10 TeV. Esta energía máxima a la que son acelerados estos rayos cósmicos pone en serias dudas la existencia de remanentes de supernova que se comporten como PeVa- trones, y por tanto, la teoría de que éstos son la fuente principal de rayos cósmicos galácticos. En el caso de SNR G24.7+0.6, con las observaciones llevadas a cabo, hemos conseguido detectar por primera vez la contrapartida de la emisión radio a energías desde 60 MeV hasta 5 TeV, MAGIC J1835–069, producida por protones que escapan del remanente de supernova y que interaccionan con una nube molecular cercana. En estas mismas observaciones, hemos podido detectar otra fuente nueva, MAGIC J1837–073, la cual está asociada, muy probablemente, con un cumulo estelar tal y como sugiere su lo- calización. Su emisión puede ser explicada asumiendo una inyección casi continua de rayos cósmicos durante la totalidad de la vida estimada del cumulo estelar. Por otra parte, el estudio del púlsar del Cangrejo, llevado a cabo con MAGIC ha re- sultado en el descubrimiento de emisión pulsada hasta 1.5 TeV, refutando cualquiera de los modelos presentados hasta el momento. Además, la curva de luz que carac- teriza la emisión proveniente del púlsar por encima de 400 GeV, presenta dos picos sincronizados en fase con los picos hallados a energías más bajas. Esta emisión, ex- tremadamente energética, únicamente puede ser producida por electrones acelerados hasta factores de Lorentz muy altos en regiones cercanas al cilindro de luz, ya sea en su interior o en su exterior, y que posteriormente colisionan y transfieren su energía a fotones térmicos.Universitat de BarcelonaParedes i Poy, Josep MariaZanin, RobertaManrique Oliva, AlbertoUniversitat de Barcelona. Departament de Física Quàntica i Astrofísica201820192018info:eu-repo/semantics/doctoralThesisinfo:eu-repo/semantics/publishedVersion175 p.application/pdfapplication/pdfhttp://hdl.handle.net/10803/663414TDX (Tesis Doctorals en Xarxa)reponame:TDR. Tesis Doctorales en Redinstname:CBUC, CESCAInglésL'accés als continguts d'aquesta tesi queda condicionat a l'acceptació de les condicions d'ús establertes per la següent llicència Creative Commons: http://creativecommons.org/licenses/by-nc-sa/4.0/http://creativecommons.org/licenses/by-nc-sa/4.0/info:eu-repo/semantics/openAccessoai:www.tdx.cat:10803/6634142026-06-14T12:46:07Z |
| score |
15,198674 |