Roland Diehl"The Origin of 44Ti", 15 Jan 2009

Comparing Abundances of 44Ti and other Isotopes

Roland Diehl"The Origin of 44Ti", 15 Jan 2009

4444TiTi γγ--rays fromrays from CasCas AA

44Ti Ejected Mass ~0.8-2.5 10-4 M

44Ti

44Ca

τ =85y, EC

44Sc

τ = 5.4 h, β+

τ=85y (Ahmad et al. 2006)

SPIMartin et al.'06

IBISRenaud et al. '06

Roland Diehl"The Origin of 44Ti", 15 Jan 2009

4444Ti Yield of ccTi Yield of cc--SNe: UncertaintiesSNe: UncertaintiesAt Discovery Time of Cas A: 44Ti Lifetime UncertaintyNow: 44Ti Abundance Measurement on Cas A, Astrophysics

Absolute Abundances are a Challenge!What about abundance ratios?

Roland Diehl"The Origin of 44Ti", 15 Jan 2009

Abundances in Stellar PhotospheresAbundances in Stellar Photospheres

Asplund et al. 2005

The Reference: Our SunSolar Abundances are Difficult to Assess

Main Components: X=0.7392, Y=0.2486, Z= 0.0122 (Asplund et al. 2004)But, e.g.:

Metal Fraction Z/X: now 1.65%, was 2.75% (Anders & Grevesse 1989)

C Abundance: down by 0.17 dex, overall more consistent now(Lodders 2003)

Change of BASELINE for Nucleosynthesis-Yield Evaluations!

re-analyzed (3D)

Roland Diehl"The Origin of 44Ti", 15 Jan 2009

1D versus 3D Photosphere Models1D versus 3D Photosphere Models

Convective Motion Inadequately Addressed in 1D"Microturbulence" CorrectionsNon-Matched Line Profiles

3D EffectsGranulation of Convection CellsDoppler Shifts of Lines are Depth-Dependent

M. Asplund 2000; 2005;...

Roland Diehl"The Origin of 44Ti", 15 Jan 2009

Impact of 3D Models of the Solar PhotosphereImpact of 3D Models of the Solar Photosphere

Intermediate-Mass Element Systematics:non-LTE Effects are Significant -> ~0.1-0.2 dex UncertaintyGranulation/3D Effects Uncertain (only LTE-Studies so far)

Roland Diehl"The Origin of 44Ti", 15 Jan 2009

Cas A: How Much Cas A: How Much 5656Ni?Ni?Cas A was NOT Seen as Bright SN

No Historical "SN Report" – (except controversial:

Flamsted 6thmag 16 Aug 1680)– Cas A = "sub-luminous" SN?

Dust-Enshrouded SN Explosion?Abnormal Ratio of NH versus X-ray Scattering in ISM along LoS

– Cas A Progenitor-Produced Dust Shell-> Occultation of SN Light

– Destroyed by SN Shock -> Seen in NH Excess

Indirect Cas A Brightness EstimateSN Light Echo

– Krause et al. 2008, Cloud at 266 ly from Cas A– Similarity to SN1993J, i.e. Cas A = SN Type IIb

– 56Ni Mass Estimated as 0.05...0.15 M

Roland Diehl"The Origin of 44Ti", 15 Jan 2009

SN1987ASN1987A• Radioactivity as Energy Source of SN Light

Energy Deposition and -Conversion ModelRadioactivity Gamma-Rays and PositronsSN Envelope Composition and Dynamics HistoryLight Curve Models, with M(56Ni/57Ni/44Ti) as Parameters -> Fit to Obs

Observational AccessBolometric SN LightOptical LinesIR Lines

– [FeI] at 24.05 μm– [FeII] at 25.99 μm

Fransson & Kozma 2001

Roland Diehl"The Origin of 44Ti", 15 Jan 2009

SN1987A: Amounts of SN1987A: Amounts of 5656Ni/Ni/5757Ni/Ni/4444TiTi

Early LightcurveM(56Ni)=0.071 M (Sunzeff&Bouchet'90)M(57Ni)=3.3 10-3 M (Fransson & Kozma 1993)

Late IR Light CurveM(44Ti)=1.5 10-4 M (Kozma+ 2000)

– (bolometric LC at <3270d)

M(44Ti)=1-2 10-4 M (Chugai+ 1997) – (optical lines at 2875d)

M(44Ti)=<1 10-4 M (Lundquist+ 2001) – (Far-IR lines FeII 26μm at 2875d)

M(44Ti)=<1.5 10-5 M (Borkovski+ 1997) – (Far-IR lines FeII 26μm at 3425d)

M44Ti=5 10-5M

Lundquist+, 2001

Fransson & Kozma 2001

Roland Diehl"The Origin of 44Ti", 15 Jan 2009

Light Curve Models: DiscussionLight Curve Models: Discussion

Basic ProcessesRadioactive Energy Deposits (gamma-rays, positrons)

– gamma-ray deposit ~ gas density– positron deposit ~gas density & magnetic-field structure

Inelastic Photon Scattering in Expanding Envelope– line opacities, line energy ~ expansion velocities

Thermal / Collisional Excitations– collisional temperature

Approximately:Local Energy Deposit & Dominating Photon Diffusion (t<40...50 days)Distributed Energy Deposit & Energy Conversion (t>50 d)

CaveatsNo thermodynamic equilibrium, Tcollisional < TionizationLine opacities are importantResonant scatterings are important3D mixings of radioactivity are importantCompositions of Envelope & Swept-Up ISM are importantAnisotropy of E deposit & photon transport incurs limb brightenings

Roland Diehl"The Origin of 44Ti", 15 Jan 2009

CoreCore--Collapse SN NucleosynthesisCollapse SN NucleosynthesisWoosley & Weaver 1995

44Ti Yields are Sensitive to Explosion DetailsLarger Variations/FLuctuations with Progenitor MassVery Massive Progenitors >30 M : No 44Ti (BH formation), or Huge (Ekin>1052 erg, asymmetries) 44Ti Yields

In Comparison, Most other Isotope Yields Behave More Smoothly with Progenitor MassesAre Less Sensitive to Explosion Details

Roland Diehl"The Origin of 44Ti", 15 Jan 2009

Aspherical SNe: Aspherical SNe: 4444Ti Enhancements?Ti Enhancements?

Aspherical SN Explosions:Stronger Shock in Polar RegionHigher Entropy behind ShockIncreased 44Ti Synthesis

– Nagataki 1998– Mass Cut Choice

from 0.07 M of 56Ni

Maeda & Nomoto 2003

Roland Diehl"The Origin of 44Ti", 15 Jan 2009

Using SN Profiles to Obtain Using SN Profiles to Obtain 4444Ti and Ti and 5656NiNiNuclear-Reaction Weighting with SN Structure & Dynamics

Magkotsios et al. 2008; Parikh et al. / NARF Project

Roland Diehl"The Origin of 44Ti", 15 Jan 2009

““NormalNormal”” Core Collapse Supernovae (?)Core Collapse Supernovae (?)

Consistency Check: Cas A vs. what we know about 44Ti…

44Ti from SAD/Models/SN1987A/γ-Rays, vs. 56NiOnly Non-Spherical Models Reproduce Observed Ratios

Non-spherical explosions?? (->GRB)

Cas A

Roland Diehl"The Origin of 44Ti", 15 Jan 2009

Abundance InterrelationsAbundance Interrelations

Ti Abundances Show (somewhat) Larger Scatter than Si and CaHint for rare-event synthesis?

Sestito+ 2008

Roland Diehl"The Origin of 44Ti", 15 Jan 2009

Abundances in our GalaxyAbundances in our Galaxy

Abundance Gradient within the GalaxyGeneral Trend of a Decline with Galactocentric RadiusTi and Ca are Similar to Fe

Roland Diehl"The Origin of 44Ti", 15 Jan 2009

SpatioSpatio--temporal temporal Evolution of the GalaxyEvolution of the Galaxy

Radial Gradients Provide a Key Diagnostic of Evolution

Prantzos & Boissier 1999, 2003

Roland Diehl"The Origin of 44Ti", 15 Jan 2009

Chemical Evolution of the GalaxyChemical Evolution of the Galaxy

• Modeling Abundance EvolutionsStar Formation HistorySource YieldsMixing and Infall Works for Some Elements, not for Others…

Modeling Standard Abundances(same ingredients) Agreement is Good, ~Factor 2

There are Missing Pieces…Nuclear Reactions?Stellar & SN Models?Matter Cycling / ISM Flows?

Roland Diehl"The Origin of 44Ti", 15 Jan 2009

Inverting the Argument: Inverting the Argument: What the Galaxy Tells Us About YieldsWhat the Galaxy Tells Us About Yields

Fitting GCE-Model Predictions to Observation-Inferred Abundance Histories

– assuming Star-Formation and Infall Histories and IMF are Fixed by Various Constraints (e.g. star & gas distributions, spatial abundance gradients)

best

-fit

yie

lds

WW

95 y

ield

s

Roland Diehl"The Origin of 44Ti", 15 Jan 2009

Ref.: Woosley & Weaver 1995Yields for O, IM Elements (Ca) and Fe Group Fe/Zn/Ni ~okCorrections Suggested for Mg, Ti, Cr, Mn, Co

Yield Consistency CheckYield Consistency Check

Roland Diehl"The Origin of 44Ti", 15 Jan 2009

Ref.: Limongi & Chieffi 2003Same as WW95: most ~ok

Massive Stars & cc-SNe ~ok

Corrections Suggested for SNIa Yields

Yield Consistency CheckYield Consistency Check

Roland Diehl"The Origin of 44Ti", 15 Jan 2009

““AbnormalAbnormal”” Core Collapse Core Collapse SupernovaeSupernovaeas as 4444Ca (=Ca (=4444Ti) Sources?Ti) Sources?

44Ti vs. 56Ni: Models compared toSolar 44Ca/56FeSN1987A & Cas A

Only Non-Spherical Models Reproduce Observed 56Ni/44Ti Ratios

Abundance Scatter:Somewhat Increased for Ti?Sky Regions with Most Massive Stars are 44Ti Source-Free (COMPTEL, INTEGRAL)

Rare Events??

The et al. 2006Cas A is the ONLY Source Seen(Iyudin et al 1994)

expectation

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Lati

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