presentation v2

Dark Cosmology Centre, Niels Bohr Institute

The role of core collapse supernovae in the context of dust production in the early universe

Mikkel Juhl HobertDark Cosmology Centre, Niels Bohr Institute

Master’s thesis

Supervisor: Darach Watson

3/22/2016Dias 1

Table of Contents

Introduction• Cosmic dust in the early universe• Core collapse supernovae and supernova remnants

My project• Dust emission and dust models• Cold dust in young core collapse supernova remnants in

the Large Magellanic Cloud


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Cosmic dust

Complex structures of one or more elements.

Only about 0.1% of interstellar matter.

Absorbs and scatters light (extinction).

Reemits absorbed light as infrared radiation.

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Dust in the early universe


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One or more processes must produce large amounts of dust, fast and efficiently.


• Death of high mass stars.• Different elements burn in

the star until the core reaches iron.

• Nuclear fusion in the core stops. The star starts to collapse.

• Inner core is compressed into neutrons and neutrinos.

• Outer material bounces on the degenerated core creating a shock.

• Shock initially halts but is revived by neutrino heating.

• Outer material is blasted away leaving a stellar remnant behind.

Core collapse supernovae

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Supernova remnants

• Free expansion phaseLasts for

• Adiabatic phaseLasts for .

• Radiative phaseLasts for .


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Dust emission

Emits thermally, not as a black body

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𝜅𝜈

❑+𝛽

Emits thermally as a gray body

(Rayleigh-Jeans regime)


Dust models

Astronomical silicates (AS)(minerals rich in Mg, Si and O) Amorphous carbon(e.g. coal and soot, rich in C).i. ACAR sampleii. BE sample

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Observing cold dust

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Spitzer Space Telescope Herschel Space Observatory

Mid infrared(MIPS)

Far infrared and submillimeter(PACS and SPIRE)


Young core collapse supernova remnants in the Large Magellanic Cloud

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Large Magellanic Cloud• Small and well-known

distance, • Face-on geometry• Rich in gas and dust• Rapid star formation• Many supernovae and

supernova remnants

Sample criteria• Young core collapse

supernova remnants• Must be in regions with little

contamination• Must be distinguishable from

the background

Cold dust in the supernova remnants


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Subtracting the background with an

annulus

Subtracting the background with a

median filter

Aperture photometry

Uniform background Varying background



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24𝜇m70𝜇m100𝜇m160𝜇m

250𝜇m350𝜇m500𝜇m



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N49



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24𝜇m





24𝜇m



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N132D



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SNR AS () (K)

ACAR () (K)

BE () (K)

SN1987AN11LN23

N132DN49

N63A


Dust from swept-up interstellar matter

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(neutral) (ionized) (molecular)


Dust from swept-up interstellar matter

SNR() () () ()

D2G*() ()

SN1987A ... ... ... 1 4.15N11L 2.64 0.81 ... 3.45 4.17 1.0N23 1.38 0.66 ... 2.04 4.44 0.2

N132D 1.34 0.87 0.21 2.63 8.26 4.5N49 3.14 1.96 0.13 5.36 6.25 6.2

N63A 0.28 2.1 ... 2.38 9.62 2.0

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*Temim et al. (2015)


Summary

• Each target must produce, on average, of dust (Dwek et al., 2007).

• Low amounts of observed dust in N11L and N23.• High amounts of observed dust in SN1987A and N63A.• Dust in N132D and N49 is probably swept up.

• Total dust mass strongly depends oni. The specific dust model.ii. The accuracy of the background subtraction.

• Still uncertainty surrounding core collapse supernovae as key contributors of dust.

• They are likely not the only significant sources of dust.

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presentation v2

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