Massive-Star Supernovae as Massive-Star Supernovae as Major Dust FactoriesMajor Dust Factories

Ben E. K. Sugerman, Barbara Ercolano, M. J. Barlow, A. G. G. M. Ben E. K. Sugerman, Barbara Ercolano, M. J. Barlow, A. G. G. M. Tielens, Geoffrey C. Clayton, Albert A. Zijlstra, Margaret Meixner, Tielens, Geoffrey C. Clayton, Albert A. Zijlstra, Margaret Meixner, Angela Speck, Tim M. Gledhill, Nino Panagia, Martin Cohen, Karl Angela Speck, Tim M. Gledhill, Nino Panagia, Martin Cohen, Karl D. Gordon, Martin Meyer, Joanna Fabbri, Janet. E. Bowey, DouglaD. Gordon, Martin Meyer, Joanna Fabbri, Janet. E. Bowey, Douglas L. Welch, Michael W. Regan, Robert C. Kennicutt Jr.s L. Welch, Michael W. Regan, Robert C. Kennicutt Jr.

Science, Science, 313313 (14 July 2006), 196-200 (14 July 2006), 196-200

Reviewed by Koji Wada, 21 Nov. 2006

AbstractAbstractType II Supernova 2003gd in the galaxy NGC 628

Optical & Mid-Infrared observation by Spitzer Space Telescope

499-678 days after outburst:

Mid-IR excessesIncreasing optical extinctionAsymmetries in the emission line profile (blueshift)

Radiative-transfer model (3-D Monte Carlo radiative-transfer code: MOCASSIN)

Dust formed within the Supernova ejecta ～ < 0.02 M

Massive-star supernovae may be major dust producers!

and others

IntroductionIntroductionHow to produce interstellar dust in the early universe:

Gentle winds of low-mass AGB stars? → too long time

Massive stars’ Type II supernovae (SNe) ? → 　 Theoretically possible (0.08-1M ), but very low (10-4M ) in previous observations

(SNe 1987A, 1999em)

Difficult to confirm, because…SNe are rare and far apartRemnants are too cold (<30K) to distinguish dust cloud

(Spitzer’s IR camera : 50 – 500 K )

Type II-P SN 2003gd (progenitor mass of 8+4-2 M )

Rare case of cotemporaneous optical and mid-IR observations!

Data in support dust productionData in support dust production

Mid-IR excess

Asymmetric blue-shifted emission lines ※ Dust obscures more emission from receding gas.

Increase in optical extinction

1. Mid-IR excess1. Mid-IR excessHubble Spitzer mid-IR

499 days 670 days

678 days, Multiband Imaging Secptrometer

3.6, 4.5, 5.8, 8.0 m

24 m

Black body fit (5.8,8.0m@499days):

480 K, L = 4.6×105 Lr = 6.8×1015 cm

2.Asymmetric blue-shifted emission line2.Asymmetric blue-shifted emission line

Asymmetry

Dust with an increasing optical depth is located within and expanding sphere of uniform emission.

Optical extinction AR < 5 for 521 days

3. Increasing optical extinction3. Increasing optical extinction

]1[)(2

005656 )/(/56

ttt eetL

(1)-rays from 56Co decay

Average opacity: 56 = 0.033 cm2/gColumn depth: 0 = 7×104 g/cm2 at t0 = 11.6 days

for SN1987A

Estimated Extinction

Dust-mass analysisDust-mass analysis3-D Monte Carlo radiative-transfer code MOCASSIN

Within Spherical, expanding shell with r = rin ～ Y rin

∝ r -2 illuminating radiation proportional to the dust density Grain size distribution : a-3.5 for a = 0.005 – 0.05 m Dust composition : 15% amorphous carbon, 85% silicates source L : according to (1) T : constant

Dust distribution : “smooth” model & “clumpy” model

•Spherical clump size rc = 0.025 (Y rin)

•Volume filling factor fc

•Density contrast = c/

•Uniformly distributed

Rayleigh-Talyor unstable

Lower mass limit

Upper mass limit

Model resultsModel resultsY = 7, rin = 5×1015 cm,L = 6.6×105 L , T = 5000 K　 ( fc = 0.02 for clumpy model )

Y = 7, rin = 6.8×1015 cm,L = 9.2×104 L , T = 5000 K　 ( fc = 0.05 for clumpy model )

499 days

678 days

High !

Interpretation of dust massInterpretation of dust massclumpy model mass : 2×10-3 M (499 days) - 2×10-2 M (678 days)

>> analytic estimates5×10-4 M (499 days) - 2×10-3 M (678 days)

>> or ~ mega-grains approximation

10-4 M for SN 1987A, 1999em → should be revisited

limited use after clumps become optically thick

10-5 M (499 days) - 4×10-4 M (678 days)

For smooth dust :

5×10-3 M (499 days)

For clumpy dust :

Discussion & ConclusionDiscussion & Conclusion

Condensation efficiency

Mass of refractory elements condensed into dustMass of refractory elements in ejecta

=

0.02 M0.16 - 0.42 M

= progenitor of SN 2003gd : 10 - 12 M solar metallicity

assumed

< 0.12

close to 0.2 needed for SNe to account for the dust content of high-redshift galaxies

∴ Supernovae play an important role in the production of dust in the early universe.