DUST PRODUCTION AND PARTICLE ACCELERATION IN SUPERNOVA 1987A REVEALED WITH ALMA (original) (raw)

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.

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.

Astro2020 Science White Paper: Are Supernovae the Dust Producer in the Early Universe?

arXiv: Astrophysics of Galaxies, 2019

Whether supernovae are a significant source of dust has been a long-standing debate. The large quantities of dust observed in high-redshift galaxies raise a fundamental question as to the origin of dust in the Universe since stars cannot have evolved to the AGB dust-producing phase in high-redshift galaxies. In contrast, supernovae occur within several millions of years after the onset of star formation. This white paper focuses on dust formation in supernova ejecta with US-Extremely Large Telescope (ELT) perspective during the era of JWST and LSST.

Type II supernovae as a significant source of interstellar dust

Nature, 2003

Large amounts of dust (>10 8 M ( ) have recently been discovered in high-redshift quasars 1,2 and galaxies 3-5 corresponding to a time when the Universe was less than one-tenth of its present age. The stellar winds produced by stars in the late stages of their evolution (on the asymptotic giant branch of the Hertzsprung-Russell diagram) are thought to be the main source of dust in galaxies, but they cannot produce that dust on a short enough timescale 6 (<1 Gyr) to explain the results in the high-redshift galaxies. Supernova explosions of massive stars (type II) are also a potential source, with models predicting 0.2-4M ( of dust 7-10 . As massive stars evolve rapidly, on timescales of a few Myr, these supernovae could be responsible for the high-redshift dust. Observations 11-13 of supernova remnants in the Milky Way, however, have hitherto revealed only 10 27 -10 23 M ( each, which is insufficient to explain the high-redshift data. Here we report the detection of ,2-4M ( of cold dust in the youngest known Galactic supernova remnant, Cassiopeia A. This observation implies that supernovae are at least as important as stellar winds in producing dust in our Galaxy and would have been the dominant source of dust at high redshifts.

Supernova Remnants and the Life Cycle of Interstellar Dust

2008

We propose to use the unique instrumental capabilities of SOFIA to conduct imaging and spectroscopic studies of supernovae (SNe), of young supernova remnants (SNRs) for which the ejecta have not yet fully mixed with the ISM, and select regions in older remnants which are interacting with the ambient ISM. These observations will address key issues within NASA’s Visions for Science quest for discovering the origin, structure, evolution and destiny of the universe: What is the origin of dust in early universe? How efficient are supernovae in producing interstellar dust? How efficient are their blast waves in destroying, processing, or even forming dust as they expand into the circumstellar and interstellar medium? How do interstellar shocks facilitate chemical reaction on the surfaces of dust grains? The answers to these questions are crucial for understanding the evolutionary cycle of interstellar dust, the role of dust in the processing of starlight and in determining the thermal bal...

Dust formation and survival in supernova ejecta

Monthly Notices of the Royal Astronomical Society, 2007

Theoretical models suggest that Type-II SNe are efficient dust factories, able to produce 0.1-1 M⊙ of dust within 0.01-0.1 Gyr from the progenitor birth. These sources can easily explain the observations of dust emission in high redshift (z∼6) QSOs, when the Universe age was ∼ < 1 Gyr. However, such high masses of dust are not observed in recent supernovae (SNe) and SN remnants (SNR), thus questioning the validity of models. We discuss the dependence of formation models on the assumptions, the evolution and survival of grains in the SN ejecta, and the extinction/emission properties of the resulting dust. Finally, we comment on the relative contribution of SNe and AGB stars to the dust production in the early universe.

Dust in historical Galactic Type Ia supernova remnants with Herschel★

Monthly Notices of the Royal Astronomical Society, 2012

The origin of interstellar dust in galaxies is poorly understood, particularly the relative contributions from supernovae and the cool stellar winds of low-intermediate-mass stars. Recently, large masses of newly formed dust have been discovered in the ejecta of core-collapse supernovae. Here, we present Herschel Photodetector Array Camera and Spectrometer (PACS) and Spectral and Photometric Imaging Receiver (SPIRE) photometry at 70-500 µm of the historical, young supernova remnants: Kepler and Tycho, both thought to be the remnants of Type Ia explosion events. We detect a warm dust component in Kepler's remnant with T d = 82 +4 −6 K and mass ∼(3.1 +0.8 −0.6) × 10 −3 M ; this is spatially coincident with thermal X-ray emission and optical knots and filaments, consistent with the warm dust originating in the circumstellar material swept up by the primary blast wave of the remnant. Similarly for Tycho's remnant, we detect warm dust at 90 +5 −7 K with mass (8.6 +2.3 −1.8)×10 −3 M. Comparing the spatial distribution of the warm dust with X-rays from the ejecta and swept-up medium, and Hα emission arising from the post-shock edge, we show that the warm dust is swept up interstellar material. We find no evidence of a cool (25-50 K) component of dust with mass ≥0.07 M as observed in core-collapse remnants of massive stars. Neither the warm or cold dust components detected here are spatially coincident with supernova ejecta material. We compare the lack of observed supernova dust with a theoretical model of dust formation in Type Ia remnants which predicts dust masses of 88(17) × 10 −3 M for ejecta expanding into ambient surrounding densities of 1(5) cm −3. The model predicts that silicon-and carbon-rich dust grains will encounter, at most, the interior edge of the observed dust emission at ∼400 years, confirming that the majority of the warm dust originates from swept-up circumstellar or interstellar grains (for Kepler and Tycho, respectively). The lack of cold dust grains in the ejecta suggests that Type Ia remnants do not produce substantial quantities of iron-rich dust grains and has important consequences for the 'missing' iron mass observed in ejecta. Finally, although, we cannot completely rule out a small mass of freshly formed supernova dust, the Herschel observations confirm that significantly less dust forms in the ejecta of Type Ia supernovae than in the remnants of core-collapse explosions.