| 1. |
- Arendt, Richard G., et al.
(författare)
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JWST NIRCam Observations of SN 1987A : Spitzer Comparison and Spectral Decomposition
- 2023
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Ingår i: Astrophysical Journal. - : American Astronomical Society. - 0004-637X .- 1538-4357. ; 959:2
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Tidskriftsartikel (refereegranskat)abstract
- JWST Near Infrared Camera (NIRCam) observations at 1.5–4.5 μm have provided broadband and narrowband imaging of the evolving remnant of SN 1987A with unparalleled sensitivity and spatial resolution. Comparing with previous marginally spatially resolved Spitzer Infrared Array Camera (IRAC) observations from 2004 to 2019 confirms that the emission arises from the circumstellar equatorial ring (ER), and the current brightness at 3.6 and 4.5 μm was accurately predicted by extrapolation of the declining brightness tracked by IRAC. Despite the regular light curve, the NIRCam observations clearly reveal that much of this emission is from a newly developing outer portion of the ER. Spots in the outer ER tend to lie at position angles in between the well-known ER hotspots. We show that the bulk of the emission in the field can be represented by five standard spectral energy distributions, each with a distinct origin and spatial distribution. This spectral decomposition provides a powerful technique for distinguishing overlapping emission from the circumstellar medium and the supernova ejecta, excited by the forward and reverse shocks, respectively.
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| 2. |
- Cigan, Phil, et al.
(författare)
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High Angular Resolution ALMA Images of Dust and Molecules in the SN 1987A Ejecta
- 2019
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Ingår i: Astrophysical Journal. - : American Astronomical Society. - 0004-637X .- 1538-4357. ; 886:1
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Tidskriftsartikel (refereegranskat)abstract
- We present high angular resolution (similar to 80 mas) ALMA continuum images of the SN.1987A system, together with CO J = 2 -> 1, J = 6 -> 5, and SiO J = 5 -> 4 to J = 7 -> 6 images, which clearly resolve the ejecta (dust continuum and molecules) and ring (synchrotron continuum) components. Dust in the ejecta is asymmetric and clumpy, and overall the dust fills the spatial void seen in H alpha images, filling that region with material from heavier elements. The dust clumps generally fill the space where CO J = 6 -> 5 is fainter, tentatively indicating that these dust clumps and CO are locationally and chemically linked. In these regions, carbonaceous dust grains might have formed after dissociation of CO. The dust grains would have cooled by radiation, and subsequent collisions of grains with gas would also cool the gas, suppressing the CO J = 6 -> 5 intensity. The data show a dust peak spatially coincident with the molecular hole seen in previous ALMA CO J = 2 -> 1 and SiO J = 5 -> 4 images. That dust peak, combined with CO and SiO line spectra, suggests that the dust and gas could be at higher temperatures than the surrounding material, though higher density cannot be totally excluded. One of the possibilities is that a compact source provides additional heat at that location. Fits to the far-infrared-millimeter spectral energy distribution give ejecta dust temperatures of 18-23 K. We revise the ejecta dust mass to M-dust = 0.2-0.4 M-circle dot for carbon or silicate grains, or a maximum of <0.7 M-circle dot for a mixture of grain species, using the predicted nucleosynthesis yields as an upper limit.
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| 3. |
- France, Kevin, et al.
(författare)
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Observing Supernova 1987A with the Refurbished Hubble Space Telescope
- 2010
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Ingår i: Science. - : American Association for the Advancement of Science (AAAS). - 0036-8075 .- 1095-9203. ; 329:5999, s. 1624-1627
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Tidskriftsartikel (refereegranskat)abstract
- Observations with the Hubble Space Telescope (HST), conducted since 1990, now offer an unprecedented glimpse into fast astrophysical shocks in the young remnant of supernova 1987A. Comparing observations taken in 2010 with the use of the refurbished instruments on HST with data taken in 2004, just before the Space Telescope Imaging Spectrograph failed, we find that the Ly alpha and H alpha lines from shock emission continue to brighten, whereas their maximum velocities continue to decrease. We observe broad, blueshifted Ly alpha, which we attribute to resonant scattering of photons emitted from hot spots on the equatorial ring. We also detect N v lambda lambda 1239, 1243 angstrom line emission, but only to the red of Ly alpha. The profiles of the N v lines differ markedly from that of H alpha, suggesting that the N4+ ions are scattered and accelerated by turbulent electromagnetic fields that isotropize the ions in the collisionless shock.
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| 4. |
- Gall, Christa, et al.
(författare)
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Rapid formation of large dust grains in the luminous supernova 2010j1
- 2014
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Ingår i: Nature. - : Springer Science and Business Media LLC. - 0028-0836 .- 1476-4687. ; 511:7509, s. 326-
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Tidskriftsartikel (refereegranskat)abstract
- The origin of dust in galaxies is still a mystery(1-4). The majority of the refractory elements are produced in supernova explosions, but it is unclear how and where dust grains condense and grow, and how they avoid destruction in the harsh environments of star-forming galaxies. The recent detection of 0.1 to 0.5 solar masses of dust in nearby supernova remnants(5-7) suggests in situ dust formation, while other observations reveal very little dust in supernovae in the first few years after explosion(1,8,10). Observations of the spectral evolution of the bright SN 2010j1 have been interpreted as pre-existing dust(11), dust formationlz(12,13) or no dust at all(14). Here we report the rapid (40 to 240 days) formation of dust in its dense circumstellar medium. The wavelength-dependent extinction of this dust reveals the presence of very large (exceeding one micrometre) grains, which resist destruction(15). At later times (500 to 900 days), the near-infrared thermal emission shows an accelerated growth in dust mass, marking the transition of the dust source from the circumstellar medium to the ejecta. This provides the link between the early and late dust mass evolution in supernovae with dense circumstellar media.
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| 5. |
- Shahbandeh, Melissa, et al.
(författare)
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JWST observations of dust reservoirs in type IIP supernovae 2004et and 2017eaw
- 2023
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Ingår i: Monthly notices of the Royal Astronomical Society. - 0035-8711 .- 1365-2966. ; 523:4, s. 6048-6060
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Tidskriftsartikel (refereegranskat)abstract
- Supernova (SN) explosions have been sought for decades as a possible source of dust in the Universe, providing the seeds of galaxies, stars, and planetary systems. SN 1987A offers one of the most promising examples of significant SN dust formation, but until the James Webb Space Telescope (JWST), instruments have traditionally lacked the sensitivity at both late times (>1 yr post-explosion) and longer wavelengths (i.e. >10 μm) to detect analogous dust reservoirs. Here we present JWST/MIRI observations of two historic Type IIP SNe, 2004et and SN 2017eaw, at nearly 18 and 5 yr post-explosion, respectively. We fit the spectral energy distributions as functions of dust mass and temperature, from which we are able to constrain the dust geometry, origin, and heating mechanism. We place a 90 per cent confidence lower limit on the dust masses for SNe 2004et and 2017eaw of >0.014 and >4 × 10−4 M⊙, respectively. More dust may exist at even colder temperatures or may be obscured by high optical depths. We conclude dust formation in the ejecta to be the most plausible and consistent scenario. The observed dust is radiatively heated to ∼100–150 K by ongoing shock interaction with the circumstellar medium. Regardless of the best fit or heating mechanism adopted, the inferred dust mass for SN 2004et is the second highest (next to SN 1987A) mid-infrared inferred dust mass in extragalactic SNe thus far, promoting the prospect of SNe as potential significant sources of dust in the Universe.
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| 6. |
- Szalai, Tamás, et al.
(författare)
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Spitzer's Last Look at Extragalactic Explosions : Long-term Evolution of Interacting Supernovae
- 2021
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Ingår i: Astrophysical Journal. - : American Astronomical Society. - 0004-637X .- 1538-4357. ; 919:1
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Tidskriftsartikel (refereegranskat)abstract
- Here we present new, yet final, mid-infrared (mid-IR) data for supernovae (SNe) based on measurements with the Spitzer Space Telescope. Comparing our recent 3.6 and 4.5 mu m photometry with previously published mid-IR and further multiwavelength data sets, we were able to draw some conclusions about the origin and heating mechanism of the dust in these SNe or in their environments, as well as about possible connection with circumstellar matter (CSM) originating from pre-explosion mass-loss events in the progenitor stars. We also present new results regarding both certain SN classes and single objects. We highlight the mid-IR homogeneity of SNe Ia-CSM, which may be a hint of their common progenitor type and of their basically uniform circumstellar environments. Regarding single objects, it is worth highlighting the late-time interacting Type Ib SNe 2003gk and 2004dk, for which we present the first-ever mid-IR data, which seem to be consistent with clues of ongoing CSM interaction detected in other wavelength ranges. Our current study suggests that long-term mid-IR follow-up observations play a key role in a better understanding of both pre- and post-explosion processes in SNe and their environments. While Spitzer is not available anymore, the expected unique data from the James Webb Space Telescope, as well as long-term near-IR follow-up observations of dusty SNe, can bring us closer to the hidden details of this topic.
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| 7. |
- Zsíros, Szanna, et al.
(författare)
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Serendipitous detection of the dusty Type IIL SN 1980K with JWST/MIRI
- 2024
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Ingår i: Monthly notices of the Royal Astronomical Society. - 0035-8711 .- 1365-2966. ; 529:1, s. 155-168
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Tidskriftsartikel (refereegranskat)abstract
- We present mid-infrared (mid-IR) imaging of the Type IIL supernova (SN) 1980K with the JWST more than 40 yr post-explosion. SN 1980K, located in the nearby (D ≈ 7 Mpc) ‘SN factory’ galaxy NGC 6946, was serendipitously captured in JWST/MIRI images taken of the field of SN 2004et in the same galaxy. SN 1980K serves as a promising candidate for studying the transitional phase between young SNe and older SN remnants and also provides a great opportunity to investigate its the close environment. SN 1980K can be identified as a clear and bright point source in all eight MIRI filters from F560W up to F2550W. We fit analytical dust models to the mid-IR spectral energy distribution that reveal a large amount (Md ≈ 0.002 M⊙) of Si-dominated dust at Tdust≈150 K (accompanied by a hotter dust/gas component), and also computed numerical SED dust models. Radiative transfer modelling of a late-time optical spectrum obtained recently with Keck discloses that an even larger (∼0.24–0.58 M⊙) amount of dust is needed in order for selective extinction to explain the asymmetric line profile shapes observed in SN 1980K. As a conclusion, with JWST, we may see i) pre-existing circumstellar dust heated collisionally (or, partly radiatively), analogous to the equatorial ring of SN 1987A, or ii) the mid-IR component of the presumed newly-formed dust, accompanied by much more colder dust present in the ejecta (as suggested by the late-time the optical spectra).
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