The Origin and Nature of Dust in Core Collapse Supernovae
Eli Dwek
Goddard Space Flight Center HST image of the Carina Nebula formation in injection into removal from stellar winds and the the ISM ejecta of CCSN & SNIa(?) diffuse by star ISM formation
destruction, shattering by expanding SNR growth by accretion in molecular clouds
incorporation into molecular clouds The double role of Supernovae
✦ Core collpase supernova (CCSNe) are important sources of interstellar dust • dust forms in the expelled radioactive ejecta
✦ The are the most important destroyers of interstellar dust during: • the reverse shock phase of the expansion • during the remnant phase of the expansion
✦ Are CCSN net producers or destroyers of interstellar dust?
✦ Can they produce observable amounts of dust in the early universe? GRAIN DESTRUCTION BY SUPRNOVA REMNANTS (A) sputtering
Grain destruction by supernova (B) evaporative collision
remnants (C) fragmenting collision
(Temim+2015)
SN blast wave
Supernova remnants clear all the dust
contained in ≈ 1,000 - 2,000 Msun of ISM gas (Slavin, Dwek, & Jones 2015) DUST FORMATION IN CORE COLLAPSE SUPRNOVAE Dust formation in core collapse SN SN1987A
(Wooden et al. (Matsuura + 2011, 2015) 1989, 1993) -3 Mdust ≈ 0.5 Msun Mdust ≈ 10 Msun
Cas A
Spitzer spectral image Akari/Blast/Herschel search for warm (~ 35 K) dust ≈ 0.04-0.12 Msun
of dust ≈ 0.08 Msun Sibthorpe et al. 1999 (Rho et al. 2008, Arendt+2014) Barlow et al. 2010
Crab 2-temperature multi-temperature Herschel components physical model 70, 100, 160 µm Gomez + 2012 Temim + 2013
Md ≈ 0.24 Msun Md ≈ 0.12 Msun When are CCSNe net dust producers?
Rate of ISM mass SN dust-to-gas grain cleared of = rate X X mass ratio destruction dust by single SNR
~ 1000 Msun X D2G
Rate of net SN grain dust yield = rate X destruction in CCSNe
~ 0.1 Msun
CCSN are net dust producers when D2G ≈ 10-4 Very early universe DUST FORMATION IN THE EARLY UNIVERSE How to make a dusty high-z galaxy II: need rising UV and efficient dust formation
(Dwek, Staguhn, Arendt et al. 2014)
Kroupa stellar Low-metallicity IMF produces more UV initial mass function (IMF)
low-Z IMF (top heavy)
solar-Z IMF Second constraint: Dust production Dust mass inferred from the energy constraint must be produced within ~ 500 Myr Only considered dust production by CCSN
Dust evolution models correlate the following quantities:
Star formation rate Stellar IMF Stellar mass Dust mass Gas mass Dust destruction Optical Depth in the early universe
M ⌧( ) d ( ) ⇡ ⇡R2
7 For a dust mass of 10 Msun and a mass abs coef. of 104 cm2 gr-1
10 ⌧(UV) ⇡ R(kpc)2 CCSN DUST YIELDS IN THE LOCAL UNIVERSE THE NATURE OF DUST IN SN1987A SN shock-ring interaction Dust in SN1987A Collisionally-heated dust
Zanardo et al. 2014 Dwek et al. 2010 Larsson et al. 2011 silicate
Td≈180 K -5 Md≈10 Msun
Dust that formed in the SN ejecta Matsuura et al. HST ALMA 870 µm 2011, 2015 mostly carbon
Td≈20 K
Md≈0.4 Msun Mass of dust evolved by cold accretion
Matsuura et al. 2011, 2015 Wooden et al. 1993 Wesson, Barlow, et al. 2015 Dwek et al. 1992 Amorphous carbon ~ 0.5 Msun -3 Silicate ~ 2.4 Msun ~ 10 Msun of carbon dust Iron ~ 0.4 Msun
Amorphous carbon ~ 0.3 – 0.5 Msun Silicate ~ 0.5 - 0.07 Msun
day 615
day 775 day 1144 1992ApJ...389L..21D Problems with this evolutionary model
✦ Abundance violation • – Uses more material (primarily C) than available in ejecta ✦ Predicts no silicates from CCSN • - featureless spectrum interpreted as evidence for the absence of silicates • - Silicates are an important component in Cas A spectrum • - Silicate features absent at earaly times because of optical depth effects
✦ Cold accretion • - Most of the dust growth/formation occurs at T < 500 K • - Loosely bound mantles will not survive reverse shock • - Dust will not give rise to silicate features 4 Hiding5 the dust in T(sil) = 610 K day 615 TABLE 2 Evolution of Dust Parameters and Ejecta Radius1 optically-thick clumps Epoch (day) 615 775T(ac) 1144 =450 8815 K 9090
Pure silicates (MgSiO3) ··· ··· Md(M⊙) tot0.40 0.40 0.40 (Dwek & Arendt 2015) Td(K) 607 334 145 ··· ··· Pure amorphousAC carbon ⌧(20 µm) 9100 Md(M⊙) 0.047 0.047 0.047 ⇡··· ··· sil ··· ··· Td(K) 454 333 120 15 Composite grains 2 Rej =4.8 10 cm ··· ··· ··· ± ± Md(M⊙) 0⇥.42 0.07 0.45 0.08 Td(K) ··· ··· ··· 26.3 25.2 fixed parameters: Elemental abundances in dust Mg(M⊙)0.0960.0960.0960.0900.095M(Si), M(Mg), M(C), Rej Si(M⊙)0.110.110.110.110.11 C(M⊙)0.0470.0470.0470.0450.048day 775 16 3 T(sil) = 330 K Rej [10 cm] 0.48 0.61 0.90 6.9 7.1 4 5 5 3 LIR (L⊙) 3.6 × 10 1.2 × 10 7.0 × 10 310±27 270±19 τ(λ)5 9130 5650 252 0.33 0.33 free parameter: Tdust 1 Entries in bold were held constant. The spectraT(ac) from the last =330two epochs K were fit with ellipsoidal composite grains. Grains in the first three epochs consist of a mixture of spherical silicates (MgSiO3), and amorphous carbon (AC) grains. 2 The composite grains consist of an MgSiO3 matrix with AC inclusions occupying 18% of the 3 grain’s volume. ⌧(20 µm) 5700 3 The ejecta radius, Rej ,ateachepochwascalculatedforaconstantexpansionveloc⇡ ity of 910 km s−1. 15 4 R =6.1 10 cm For comparison, on day 1144 the U to 20 µm(uvoir)luminosityis3400ej L⊙ (Suntzeff et al. 1991). ⇥ 5 The optical depth, τ(λ)isgivenbyEquation(3),andcalculatedataroundthepeakwavelength of the emission for each epoch, at 20, 20, 50, 200, and 200 µm, respectively. Fig. 2.— Fits to the observed spectrum with composite grains Fig. 3.— The spectra on days 615 and 775, obtained with a consisting of MgSiO3 and AC with volume filling factors of 82 and combination of pure MgSiO3 silicates (blue line) and amorphous each epoch, and is also capable of accounting for the 18%, respectively. Detailed description of the fits and tabulated carbon (AC) grains (red line). Masses of theday two 1144 components were UVOT(sil) region = of the150 SN lightK curve. masses are given in the text and in Table 2. fixed and determined by the masses of Mg, Si, and C locked up We will assume the presence of N identical dusty in dust in epochs 8515 and 9090. The total flux is given by the c clumps with a dust mass mc = Md/Nc,whereMd is is the average density of the grain. If Md is the total green line. Detailed description of the fits and tabulated masses T(ac) =250 K dust mass, then the mass of Mg, Si, and C locked up in are given in the text and in Table 2. the total dust mass in the ejecta, and radius rc. We also assume that the clumps maintain pressure equilibrium the dust is given by 0.24 fs (ρs/ρ) Md,0.28 fs (ρs/ρ) Md, sidering the fact that we forced the silicates and carbon with their surroundings so that the ratio rc/R,whereR and fc (ρc/ρ) Md, respectively. For an AC filling factor of to radiate at a single temperature. The figure shows that 3 is the outer radius of the ejecta, remains constant with 0.18 we get ρ =2.95 g cm , MgSiO3 and AC mass frac- the silicate 9.7 and 18 µm emission features have been in- ⌧(50 µm) 250 tions of 0.89 and 0.11, respectively, and Mg and Si mass ternally absorbed by the silicate-carbon dust mixture, as time. We also assume⇡ the presence of some dust mass, mic, in the interclump medium. fractions of 0.21 and 0.25, respectively. The elemental evident from the strong absorption features in the carbon Fig. 1.— The mass absorption coefficients used in this paper. Left panel:Sphericalsilicate(MgSiO3)andamorphouscarbongrains; The volume filling factor15 of the clumps is given by: masses locked up in the dust are presented in Table 2. dust emission. Rej =9.0 10 cm Right panel:Ellipsoidalcompositegrains.Thebluecurvecorrespondsto pure ellipsoidal MgSiO3 grains. Successive curves represent 3 the effect of added AC inclusions with fractional volume filling factor of 0.016, 0.028, 0.05, 0.09, 0.16, 0.28, and 0.50. The green curve About half of the MgSiO3 mass consists of O which, be- ⇥fV = Nc x . (6) 3.2.3. represents the κ used to fit the spectra of epochs 8515 and 9090, and correspondstograinswithMgSiO3 and AC volume filling factors of, cause of its large abundance in the ejecta ( 1 M⊙), does Day 1144 The number of clumps and theirrespectively, radii are constrained 82 and 18%. not impose any constraints on the mass of∼ dust that can Fig.We 4.— selected the 10 and 20 µm photometric data ob- by the requirement that the projected area of the clumps form in the ejecta. The spectrum corresponding to the same dust composi- sion. However, the shape effect in AC grains does not tionstained as inwith epochs the 615 Cerro and Tololo 775, but Inter-American with temperatures Observatory constrained be equal to that of the the homogeneous sphere. This TABLE 1 The results show that the late-time spectra require to(CTIO) obey the on observed day 1144 upper to limit represent on the IR the flux observations at 50 µm. Detailed taken 2 2 only increase their long wavelength emissivity, it also ∼ requirement reduces to the constraint that Nc rElementalc = ξ R , Yields of a 20 M⊙ Star 0.09 M⊙ of Mg, 0.1 M⊙ of Si, and 0.046 M⊙ of C description of the fits and tabulated masses are given in the text considerably flattens it with wavelength. Since most of during the 935 to 1352 d interval (Suntzeff et al. 1991). where ξ is a factor of order unity that compensates for to be locked up in∼ dust. From Table 1,∼ we see that these and in Table 2. the emission in the Matsuura model is attributed to AC For day 1144 we also have a 50 µm upper limit reported the overlapping of clumps along a givenMetallicity line of sight. C Mg Si Fe Reference1 masses are well within their expected yields, alleviating by P. M. Harvey, and presented by Dwek et al. (1992). dust, the resulting spectrum became too broad to fit the tion of X- and γ-rays from the SN, and the high ioniza- The optical depth of each clump, τc, is simply related the abundance problems of previous models. A low resolution (λ/∆λ =40)16-30µmspectrumofthe 0.004 0.097 0.101 0.124 0.074 [1] observations. To circumvent these problems we adopt tion rate in its envelope, required the macroscopic mixing to τh,thatofthehomogeneoussphere,by0.020 0.245 0.095 0.068 0.089 SN was obtained with the KAO around day 1151 (Dwek 2 a dust model consisting of ellipsoidal composite grains, 3.2.2. Days 615, and 775 of clumps containing radioactive Ni, Co, and Fe through- 0.008 0.144 0.098 0.096 0.080 et al. 1992). Several emission lines were detected, and 3 Md/Nc τh comprising mostly of a silicate (MgSiO3) matrix with out the ejecta (Graham 1988; Li et al. 1993). Further- τc = κ = 0.008 0.250(7) 0.096 0.11 0.075 [2] 2 1 AC inclusions. The elongated shape increased the dust The most detailed spectra of SN1987A during its early more,the upper the lacklimit of set silicate on the emission continuum features intensity in the is consis- early 4 ! πrc " ξReferences: [1]-Nomoto et al. (2006); [2]- Woosley et al. emissivity, and the addition of AC inclusions further in- evolutionary stages were presented by Wooden et al. IRtent spectra with the (days CTIO 615, 20 775)µm detection. was attributed Figure to 4 the presents fact The clumps are therefore optically thick(1988) at UVOIR wave- 2 creased the dust emissivity, with only minor flattening of (1993). As mentioned before, the lack of spectral feature thatthe CTIO the dust data may and have the formed 50 µm in upper optically limit. thick As for clumps days lengths at all early epochs before day 1144,Yields so for that this their metallicity were obtained by logarithmic interpolation between Z=0.004 and 0.02 its wavelength dependence. has been construed as evidence for the lack of silicate (Lucy615 and et 775, al. 1989, we assumed 1991). thatIn the the following dust giving we show rise to that the cross section can be taken as equal to the geometrical dust in the ejecta. To test this conclusions we ran mod- emission consists of a combination of spherical MgSiO3 2 Figure 1 depicts the various mass absorption coeffi- the results of our calculations can be simply extended to value π rc . along the major and minor axes of the ellipse (Indebe- els with pure spherical silicate (MgSiO3) and AC grains, aand clumpy AC grains medium. with masses identical to this in epochs 615 The probability that at photontouw passes et al.a distance 2014). Forz simplicity we will adopt a spherical cients considered in our models. In the Rayleigh limit, in which the mass of Mg and Si in the dust was taken to andIn 775, the following and allowed we thewill temperature construct a simple to vary. model Figure for 4 through the ejecta without absorption,shape and for then the ejecta hits a with a constant expansion velocity where a<<λ, the mass absorption coefficient of the be equal to that derived for epochs 8515 and 9090. The ashows clumpy the ejecta.fit to the Since observed the spectrum. ejecta is optically The dust thin masses at clump in the z and z + dz intervalof is givenv =(1350 by: 7502)1/3 =910kms−1. The radius of dust is independent of grain radius. The left panel shows only variables were the silicate and AC dust tempera- lateand epochs temperatures (days 8515 are presented and 9090), in the Table model 2. is relevant the ejecta at the× different epochs is given in Table 2. On the wavelength dependence of κ(λ) for pure spherical tures. The resulting spectra are shown in Figure 3. The dz MgSiO (blue curve) and amorphous carbon (red curve) only for the epochs4. when the homogeneous ejecta was P (z) dz =exp( z/ℓday) 9000 it is about(8) 7 1016 cm, and its radial 200 µm 3 4 CLUMPY EJECTA − ℓ optical depth of the ejecta is 10 and 6000 for these two optically thick. Using the same dust mass and compo- optical depth is 0.3.× Since the ejecta is optically thin grains. Optical constants for the silicate dust were taken epochs, giving rise to smooth∼ featureless spectra. They So far we assumed that the ejecta can be approximated 2 −1 from J¨ager et al. (2003), and those for the AC dust from sition as in the homogeneous model, we show that the where ℓ =(ncπrc ) is the photonat these mean epochs, free path∼ we start our analysis with the spectra provide a surprisingly good fit to the observations con- by a dusty sphere of radius R. However, the early detec- (Zubko et al. 1996). The right panel depicts the wave- clumpy model can reproduce the same IR spectrum at through the ejecta, and nc is theof number those epochs. density of length dependence of the ellipsoidal composite grains. 3.2.1. Days 8515 and 9090 The blue curve corresponds to pure MgSiO3 grains. The black curves give the values of κ for the composite grains High resolution ALMA images at 450 and 850 µm with different amount of AC inclusions (see figure cap- clearly resolved the emission from the ejecta and the cir- tion). The green curve corresponds to the mass absorp- cumstellar ring (Indebetouw et al. 2014; Zanardo et al. tion coefficient of the composite grains used to fit the 2014). Spectral observations, summarized by Matsuura 8515 and 9090 epochs spectra. et al. (2015), showed that the far-IR/submm fluxes ob- We assumed that the dust radiates at a single tem- tained by Spitzer and ALMA observations are domi- perature and used the IDL routine MPFIT (Markwardt nated by continuum emission from ejecta dust, except 2009) to simultaneously fit the SN1987A flux densities for for the 70 µm flux, which may be contaminated by the the two epochs, with the dust masses and temperatures [O I] 63µm line and by the continuum emission from the as variables. We experimented with different concentra- hot dust in the circumstellar ring (Dwek et al. 2010). tions of AC inclusions. The results presented here are The combined Spitzer and ALMA measurements of the for composite grains with MgSiO and AC volume fill- far-IR and submillimeter flux densities of SN1987A used 3 ing factors of fs =0.82 and fc =0.18, respectively. The in our analysis were taken from (Matsuura et al. 2015, choice of parameters was driven by the constraints on the their Table 1). We adopt here their estimate that at least available mass of Mg and Si in the ejecta. The result- 2/3 of the observed flux in the 70 µm band arises from ing spectra are shown in Figure 2, and the resulting dust the ejecta dust. masses and temperatures are summarized in Table 2. To minimize the mass of dust in the ejecta, Matsuura The mass fraction of MgSiO and AC in the grain are et al. (2015) considered the possibility that the dust 3 given by fs (ρs/ρ)andfc (ρc/ρ), respectively, where ρs = grains are in the shape of elongated ellipsoids. Elon- 3 3 3.2gcm and ρc =1.8gcm are, respectively, the mass gated grains radiate more efficiently at long wavelengths, densities of MgSiO and AC grains, and ρ = f ρ + f ρ thereby lowering the mass needed to produce the emis- 3 s s c c THE MASS AND COMPOSITION OF UNSHOCKED DUST IN CAS A SNR How much dust will survive the reverse shock?
Cas A: emission from dust Old SNR near Galactic center
Lau et al. 2015
Md ≈ 0.02 Msun Arendt, Dwek + 2014 shocked dust
Md ≈ 0.04 Msun shocked dust
Md ≈ 008 Msun not yet shocked dust Line emitting regions Spatial decomposition of the IR dust emission in Cas A Arendt, Dwek + 2014
Dust emission spectra from the different regions Determining the composition of the unshocked dust in Cas A
Shocked dust Unshocked dust correlated with ArII - - correlated with SiII emitting region emitting region contains fraction of - - contains most dust mass dust mass - composition UNKNOWN - composition dominated by silicate dust (see also Barlow et al. 2010) THE MASS AND COMPOSITION OF DUST IN THE CRAB NEBULA The Crab Nebula
7’x7’ SL: ~5-14 µm
LL: ~14-38 µm
Mdust ≈ 0.24 Msun Mdust ≈ 0.12 Msun
(Gomez et al. 2012) (Temim et al. 2012) OBSERVING GRAIN DESTRUCTION BY THE REVERSE SHOCK IN SN1987A Observing the grain destruction phase in JWST
Dust collisionally heated Ejecta morphology: in a shocked O-rich gas. Ejecta heated by X-ray from the reverse shock Dust lifetime ~ 10 days (Larsson et al. 2013) -5 Assuming: Mdust = 10 Msun
Tdust = 450 K CATCHING DUST FORMING SUPERNOVAE INFRARED HANDED (looking at SN that exploded in the last ~ 6 years) The evolution of the IR spectrum of SN1987A
day 100
day 2000 Observing the dust formation phase with JWST SN dust Science with JWST
✦ Observations of SN 1987A • Grain destruction by reverse shock • Nature of dust, silicates of carbon, in the ejecta ✦ Observations of SNR • Cas A: mass and composition of unshocked dust • Crab Nebula: mid-IR mapping, spectroscopy? • yield of dust that survives the reverse shock ✦ Observations of young dust-forming SNe • looking at SNe that exploded withing the last ~ 3yrs • initial dust yield from CCSNe END