The formation of nebular spectra in core-collapse supernovae [Elektronische Ressource] / Jakob Immanuel Maurer

Jakob Immanuel Maurer

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• Physik

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• Publié par: technische_universitat_munchen
• Publié le: 01 janvier 2010
• Nombre de lectures: 16
• Langue: English
• Poids de l'ouvrage: 3 Mo

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M P  I  ¨ A
TheFormationofNebularSpectra
inCore CollapseSupernovae
JakobImmanuelMaurer
Vollständiger Abdruck der von der Fakultät für Physik der Technischen Universität München zur Erlangung des
akademischenGradeseines
DoktorsderNaturwissenschaften
genehmigtenDissertation.
Vorsitzender: Univ. Prof. Dr. St. Paul
PrüferderDissertation:
1. Hon. Prof. Dr. W.Hillebrandt
2. Univ. Prof. Dr. H.Friedrich
DieDissertationwurdeam13.10.2010beiderTechnischenUniversitätMünchen
eingereichtunddurchdieFakultätfürPhysikam26.11.2010angenommen.Contents
1. Supernovae 1
1.1. HistoryofSupernovaAstronomy . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
1.2. Classification . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
1.2.1. ThermonuclearSupernovae . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
1.2.2. Core CollapseSNe . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
1.2.3. Pair InstabilitySNe . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
1.3. Supernovae&Astrophysics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
2. AtomicPhysics 15
2.1. RadiativeProcesses . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
2.2.veData . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
2.2.1. Hydrogen . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
2.2.2. Oxygen . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
2.3. CollisionalProcesses&Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
3. TheNebularPhase 27
3.1. NebularPhysics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
3.2. TheOne DimensionalNebularCode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28
3.3. TheThree DimensionalNebularCode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30
3.3.1. Three dimensionalheattransport . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30
3.3.2.lineprofiles . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31
3.3.3. Thenewionisationtreatment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33
4. CharacteristicVelocitiesOfStripped EnvelopeCore CollapseSupernovae 37
4.1. DataSet . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38
4.2. SpectralModelling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40
4.3. Discussion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45
4.3.1. Tests . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45
4.3.2. DiscussionoftheMethod . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45
4.4. Results. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49
4.5. Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53
5. OxygenRecombinationinStripped EnvelopeCore CollapseSupernovae 55
5.1. OxygenlinesinthenebularphaseofCC SNe . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55
5.1.1. Effectiverecombinationratesforneutraloxygen . . . . . . . . . . . . . . . . . . . . . . . 55
5.1.2. Recombinationlineformation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 59
5.1.3. ExcitationoftheO 7774Åline . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 61
5.1.4. TestModel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 63
5.1.5. Emissionversusabsorptionlineshapes . . . . . . . . . . . . . . . . . . . . . . . . . . . . 65
5.2. AshellmodelofSN2002ap . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 66
5.3. A2DmodelofSN1998bw . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 67
5.4. Discussion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 70
5.5. Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 74
iContents
6. HydrogenandHeliumInStripped EnvelopeCore CollapseSupernovae 77
6.1. HandHeinthenebularphase . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 78
6.1.1. Hydrogen . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 78
6.1.2. Helium . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 79
6.1.3. MixedH/Helayers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 79
6.2. SN2008ax . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 83
6.3. OtherSNeofTypeIIb . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 88
6.3.1. SN1993J . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 89
6.3.2. SNe2001ig&2003bg . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 89
6.3.3. SNe2007Y . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 90
6.4. Analternativetoshockinteraction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 91
6.5. Discussion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 95
6.5.1. LateHαemission . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 95
6.5.2. NebularlineprofilesofSNeIIb . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 96
6.5.3. SN2008ax . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 96
6.6. Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 97
7. Supernova1987A 99
7.1. NebularModellingofSN1987A . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 100
7.2. Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 104
8. Conclusions 105
Bibliography 109
ii1. Supernovae
1.1. HistoryofSupernovaAstronomy
The term ’nova’ stems from the Latin denomination for ’new star’ (stella nova) since to observers of yesteryear
novaeappearedtobemomentaryappearancesofstar likespotsinthenightskies. Theterm’supernova’wascoined
muchlaterinthe1930s,tohigh lighttheextraordinaryluminosityofthoseevents.
The earliest records of ’new stars’ reach back up to three thousand years and essentially hail from the Far East,
but also from the Near East and Europe. A clear identification of historical supernovae is often not possible, since
confusionwithcometsandclassicalnovaecannotbeexcluded. However,somehavebeenidentifiedunambiguously.
Thebestknownexamplesaredatedtotheyears1006,1054,1572and1604A.D.
Supernova 1006 is to this day the brightest (apparent magnitude) supernova recorded. Contemporary witnesses
compareditsluminancewiththatofthemooninthefirstquarter. Scoresofreportsfromallovertheworldareavail
able. Thankstotheserecordssupernova1006canbelinkedtotheremnantPKS1459 41(e.g. Clark&Stephenson
1977).
Only 48 years later supernova 1054 was observed. Its luminance was comparable to that of Venus at maximum
light. Thanks to numerous reports mainly from Asia and the Near East, today supernova 1054 can be associated
with the Crab Nebula (Mayall & Oort 1942, Clark & Stephenson 1977), discovered by John Bevis in 1731. The
Crab Nebula has played an important role for the development of modern astronomy. It is the strongest persistent
sourceof γ raysintheskyandhasprovidedastronomerswithobservationsofvariousradiationphenomena,which
were hardly observed before, like synchrotron radiation and pulsar emission. The centre of the Crab Nebula hosts
the Crab Pulsar, which was among the first neutrons stars discovered in the 1960s and has been studied intensively
sincethen.
Supernova 1572 occurred near the constellation Cassiopeia and was comparable in brilliance to supernova 1054.
In contrast to the Far and the Near East, astronomy in Europe had undergone a rapid development during the Re
naissanceinthe15thand16thcentury. ParticularlythankstotheworkoftheDanishastronomerTychoBrahethere
is more information about supernova 1572 than for any other recorded before. An amelioration of the Sextant al
lowed him to determine the position of this supernova relative to other stars accurately. For that reason its remnant
(3C10) can be unambiguously identified with the supernova (Argelander 1864, Hanbury Brown & Hazard 1952).
Furthermore it was possible to reconstruct the light curve of supernova 1572 (Baade 1945), since detailed compar-
isons between the apparent luminosity of the supernova and other planets and stars over a period of one year exist.
Supernova 1572 is a ’normal’ Type Ia (see below), as it was found from its light echos (Rest et al. 2008, Krause
etal.2008).
In1604,just32yearslater,anotherbrightsupernovaappearedatthefirmament. DetailedreportsfromFabricius,
KeplerandotherEuropeanastronomers,butalsofromKoreaallowtoreconst