Dust formation in the ejecta of the type II-P supernova 2004dj (original) (raw)

DUST AND THE TYPE II-PLATEAU SUPERNOVA 2004dj

The Astrophysical Journal, 2011

We present mid-infrared (MIR) spectroscopy of a Type II-plateau supernova, SN 2004dj, obtained with the Spitzer Space Telescope, spanning 106-1393 d after explosion. MIR photometry plus optical/near-IR observations are also reported. An early-time MIR excess is attributed to emission from non-silicate dust formed within a cool dense shell (CDS). Most of the CDS dust condensed between 50 d and 165 d, reaching a mass of 0.3 × 10 −5 M ⊙ . Throughout the observations much of the longer wavelength (> 10 µm) part of the continuum is explained as an IR echo from interstellar dust. The MIR excess strengthened at later times. We show that this was due to thermal emission from warm, non-silicate dust formed in the ejecta. Using optical/near-IR line-profiles and the MIR continua, we show that the dust was distributed as a disk whose radius appeared to be shrinking slowly. The disk radius may correspond to a grain destruction zone caused by a reverse shock which also heated the dust. The dust-disk lay nearly face-on, had high opacities in the optical/near-IR regions, but remained optically thin in the MIR over much of the period studied. Assuming a uniform dust density, the ejecta dust mass by 996 d was (0.5 ± 0.1) × 10 −4 M ⊙ , and exceeded 10 −4 M ⊙ by 1393 d. For a dust density rising toward the center the limit is higher. Nevertheless, this study suggests that the amount of freshly-synthesized dust in the SN 2004dj ejecta is consistent with that found from previous studies, and adds further weight to the claim that such events could not have been major contributors to the cosmic dust budget.

A STUBBORNLY LARGE MASS OF COLD DUST IN THE EJECTA OF SUPERNOVA 1987A

The Astrophysical Journal, 2015

We present new Herschel photometric and spectroscopic observations of Supernova 1987A, carried out in 2012. Our dedicated photometric measurements provide new 70 µm data and improved imaging quality at 100 and 160 µm compared to previous observations in 2010. Our Herschel spectra show only weak CO line emission, and provide an upper limit for the 63 µm [O i] line flux, eliminating the possibility that line contaminations distort the previously estimated dust mass. The far-infrared spectral energy distribution (SED) is well fitted by thermal emission from cold dust. The newly measured 70 µm flux constrains the dust temperature, limiting it to nearly a single temperature. The far-infrared emission can be fitted by 0.5±0.1 M of amorphous carbon, about a factor of two larger than the current nucleosynthetic mass prediction for carbon. The observation of SiO molecules at early and late phases suggests that silicates may also have formed and we could fit the SED with a combination of 0.3 M of amorphous carbon and 0.5 M of silicates, totalling 0.8 M of dust. Our analysis thus supports the presence of a large dust reservoir in the ejecta of SN 1987A. The inferred dust mass suggests that supernovae can be an important source of dust in the interstellar medium, from local to high-redshift galaxies.

Dust grains from the heart of supernovae

Astronomy & Astrophysics, 2016

Dust grains are classically thought to form in the winds of asymptotic giant branch (AGB) stars. However, there is increasing evidence today for dust formation in supernovae (SNe). To establish the relative importance of these two classes of stellar sources of dust, it is important to know the fraction of freshly formed dust in SN ejecta that is able to survive the passage of the reverse shock and be injected in the interstellar medium. With this aim, we have developed a new code, GRASH_Rev, that allows following the dynamics of dust grains in the shocked SN ejecta and computing the time evolution of the mass, composition, and size distribution of the grains. We considered four well-studied SNe in the Milky Way and Large Magellanic Cloud: SN 1987A, CasA, the Crab nebula, and N49. These sources have been observed with both Spitzer and Herschel, and the multiwavelength data allow a better assessment the mass of warm and cold dust associated with the ejecta. For each SN, we first identified the best explosion model, using the mass and metallicity of the progenitor star, the mass of 56 Ni, the explosion energy, and the circumstellar medium density inferred from the data. We then ran a recently developed dust formation model to compute the properties of freshly formed dust. Starting from these input models, GRASH_Rev self-consistently follows the dynamics of the grains, considering the effects of the forward and reverse shock, and allows predicting the time evolution of the dust mass, composition, and size distribution in the shocked and unshocked regions of the ejecta. All the simulated models aagree well with observations. Our study suggests that SN 1987A is too young for the reverse shock to have affected the dust mass. Hence the observed dust mass of 0.7−0.9 M in this source can be safely considered as indicative of the mass of freshly formed dust in SN ejecta. Conversely, in the other three SNe, the reverse shock has already destroyed between 10−40% of the initial dust mass. However, the largest dust mass destruction is predicted to occur between 10 3 and 10 5 yr after the explosions. Since the oldest SN in the sample has an estimated age of 4800 yr, current observations can only provide an upper limit to the mass of SN dust that will enrich the interstellar medium, the so-called effective dust yields. We find that only between 1−8% of the currently observed mass will survive, resulting in an average SN effective dust yield of (1.55 ± 1.48) × 10 −2 M. This agrees well with the values adopted in chemical evolution models that consider the effect of the SN reverse shock. We discuss the astrophysical implications of our results for dust enrichment in local galaxies and at high redshift.

DUST AND THE TYPE II-PLATEAU SUPERNOVA 2004et

The Astrophysical Journal, 2009

We present mid-infrared (MIR) observations of the Type II-plateau supernova (SN) 2004et, obtained with the Spitzer Space Telescope between 64 and 1406 days past explosion. Late-time optical spectra are also presented. For the period 300-795 days past explosion, we argue that the spectral energy distribution (SED) of SN 2004et comprises (1) a hot component due to emission from optically thick gas, as well as free-bound radiation; (2) a warm component due to newly formed, radioactively heated dust in the ejecta; and (3) a cold component due to an IR echo from the interstellar-medium dust of the host galaxy, NGC 6946. There may also have been a small contribution to the IR SED due to free-free emission from ionized gas in the ejecta. We reveal the first-ever spectroscopic evidence for silicate dust formed in the ejecta of a supernova. This is supported by our detection of a large, but progressively declining, mass of SiO. However, we conclude that the mass of directly detected ejecta dust grew to no more than a few times 10 −4 M . We also provide evidence that the ejecta dust formed in comoving clumps of fixed size. We argue that, after about two years past explosion, the appearance of wide, box-shaped optical line profiles was due to the impact of the ejecta on the progenitor circumstellar medium and that the subsequent formation of a cool, dense shell was responsible for a later rise in the MIR flux. This study demonstrates the rich, multifaceted ways in which a typical core-collapse supernova and its progenitor can produce and/or interact with dust grains. The work presented here adds to the growing number of studies that do not support the contention that SNe are responsible for the large mass of observed dust in high-redshift galaxies.

Dust Formation Observed in Young Supernova Remnants with Spitzer

2009

We present dust features and masses observed in young supernova remnants (SNRs) with Spitzer IRS mapping and staring observations of four youngest supernova remnants: SNR 1E102.2-7219 (E0102) in the SMC, Cas A and G11.2-0.3 in our Galaxy, and N132D in the LMC. The spectral mapping data revealed a number of dust features which include 21 micron-peak dust and featureless dust in Cas A and 18-micron peak dust in E0102 and N132D. The 18 micron-peak feature is fitted by a mix of MgSiO$_3$ and solid Si dust grains, while the 21-micron peak dust is by a mix of silicates and FeO; we also explore dust fitting using Continuous Distribution of Ellipsoid grain models. We report detection of CO fundamental band from Cas A in near-infrared. We review dust features observed and identified in other SNRs. The dust emission is spatially correlated with the ejecta emission, showing dust is formed in SN ejecta. The spectra of E0102 show rich gas lines from ejecta including strong ejecta lines of Ne and O, including two [Ne III] lines and two [Ne V] lines which allow us to diagnostic density and temperature of the ejecta and measure the ejecta masses. E0102 and N132D show weak or lacking Ar, Si, and Fe ejecta, whereas the young Galactic SNR Cas A show strong Ar, Si, and S and weak Fe. We discuss compositions and masses of dust and association with those of ejecta and finally, dust contribution from SNe to early Universe.

Early Formation of Dust in the Ejecta of Type Ib SN 2006jc and Temperature and Mass of the Dust

Astrophysical Journal, 2008

SN 2006jc is a peculiar supernova (SN), in which the formation of dust has been confirmed at an early epoch of ~50 days after the explosion. We investigate the possibility of such an earlier formation of dust grains in the expanding ejecta of SN 2006jc, applying the Type Ib SN model that is developed to reproduce the observed light curve. We find that the rapid decrease of the gas temperature in SN 2006jc enables the condensation of C grains in the C-rich layer at 40-60 days after the explosion, which is followed by the condensation of silicate and oxide grains until ~200 days. The average radius of each grain species is confined to be less than 0.01 micron due to the low gas density at the condensation time. The calculated total dust mass reaches ~1.5 Msun, of which C dust shares 0.7 Msun. On the other hand, based on the calculated dust temperature, we show that the dust species and mass evaluated to reproduce the spectral energy distribution observed by AKARI and MAGNUM at day 200 are different from those obtained by the dust formation calculations; the dust species contributing to the observed flux are hot C and FeS grains with masses of 5.6times10−45.6 \times 10^{-4}5.6times10−4 Msun and 2.0times10−32.0 \times 10^{-3}2.0times10−3 Msun, respectively, though we cannot defy the presence of a large amount of cold dust such as silicate and oxide grains up to 0.5 Msun. One of the physical processes responsible for the difference between calculated and evaluated masses of C and FeS grains could be considered to be the destruction of small-sized clusters by energetic photons and electrons prevailing within the ejecta at the earlier epoch.

Dust Signatures from Late-time Infrared and Optical Observations of SN 1998S

2005

We present late-time IR (1-5 µm) and optical observations of the type IIn SN 1998S up to about 1200 days post-explosion. The shape and evolution of the Halpha and He I 1.083 µm line profiles indicate a powerful interaction with a massive progenitor wind and provide evidence of dust condensation within the ejecta. 1.5-2.5 µm spectra and HKL'M' photometry reveal strong IR emission due to hot dust in the ejecta and/or circumstellar medium (CSM). For the origin of the IR emission we favour dust condensation (at least 10^{-3} M_{sun}) in a cool dense shell (CDS) as the main IR source but do not rule out a contribution from the CSM. The late-time evolution of the intrinsic (K-L') colour of type II supernovae (SNe) may be a potentially useful tool for determining the presence or absence of a massive CSM around their progenitors.

PROPERTIES OF NEWLY FORMED DUST GRAINS IN THE LUMINOUS TYPE IIn SUPERNOVA 2010jl

The Astrophysical Journal, 2013

Supernovae (SNe) have been proposed to be the main production sites of dust grains in the Universe. Our knowledge on their importance to dust production is, however, limited by observationally poor constraints on the nature and amount of dust particles produced by individual SNe. In this paper, we present a spectrum covering optical through near-Infrared (NIR) light of the luminous Type IIn supernova (SN IIn) 2010jl around one and half years after the explosion. This unique data set reveals multiple signatures of newly formed dust particles. The NIR portion of the spectrum provides a rare example where thermal emission from newly formed hot dust grains is clearly detected. We determine the main population of the dust species to be carbon grains at a temperature of ∼ 1, 350 − 1, 450K at this epoch. The mass of the dust grains is derived to be ∼ (7.5 − 8.5) × 10 −4 M ⊙ . Hydrogen emission lines show wavelength-dependent absorption, which provides a good estimate on the typical size of the newly formed dust grains ( ∼ < 0.1µm, and most likely ∼ < 0.01µm). We attribute the dust grains to have been formed in a dense cooling shell as a result of a strong SN-circumstellar media (CSM) interaction. The dust grains occupy ∼ 10% of the emitting volume, suggesting an inhomogeneous, clumpy structure. The average CSM density is required to be ∼ > 3×10 7 cm −3 , corresponding to a mass loss rate of ∼ > 0.02M ⊙ yr −1 (for a mass loss wind velocity of ∼ 100 km s −1 ). This strongly supports a scenario that SN 2010jl and probably other luminous SNe IIn are powered by strong interactions within very dense CSM, perhaps created by Luminous Blue Variable (LBV)-like eruptions within the last century before the explosion.

Atypical Dust Species in the Ejecta of Classical

2016

Abstract. A classical nova outburst arises from a thermonuclear run-away in the hydrogen-rich material accreted onto the surface of a white dwarf in a binary system. These explosions can produce copious amounts of heavy element enriched material that are ejected violently into the surrounding interstellar medium. In some novae, conditions in the ejecta are suitable for the formation of dust of various compositions, including silicates, amorphous carbon, silicon carbide, and hydrocar-bons. Multiple dust grain types are sometimes produced in the same system. CO formation in novae may not reach saturation, thus in-validating the usual paradigm in which the C:O ratio determines the dust species. A few novae, such as V705 Cas and DZ Cru, have ex-hibited emission features near 6, 8, and 11 µm that are similar to “Unidentified Infrared ” (UIR) features, but with significant differences in position and band structure. Here, we present Spitzer IRS spectra of two recent dusty novae, V2361 Cyg...