More Like this

1. Interaction of a Supernova with a Circumstellar Disk

   https://doi.org/10.3847/1538-4357/aaa96e  

   McDowell, Austin T.; Duffell, Paul C.; Kasen, Daniel (March 2018, The Astrophysical Journal)
2. DES16C3cje: A low-luminosity, long-lived supernova

   https://doi.org/10.1093/mnras/staa1452  

   Gutiérrez, C P; Sullivan, M; Martinez, L; Bersten, M C; Inserra, C; Smith, M; Anderson, J P; Pan, Y-C; Pastorello, A; Galbany, L; et al (July 2020, Monthly Notices of the Royal Astronomical Society)

   ABSTRACT We present DES16C3cje, a low-luminosity, long-lived type II supernova (SN II) at redshift 0.0618, detected by the Dark Energy Survey (DES). DES16C3cje is a unique SN. The spectra are characterized by extremely narrow photospheric lines corresponding to very low expansion velocities of ≲1500 km s−1, and the light curve shows an initial peak that fades after 50 d before slowly rebrightening over a further 100 d to reach an absolute brightness of Mr ∼ −15.5 mag. The decline rate of the late-time light curve is then slower than that expected from the powering by radioactive decay of 56Co, but is comparable to that expected from accretion power. Comparing the bolometric light curve with hydrodynamical models, we find that DES16C3cje can be explained by either (i) a low explosion energy (0.11 foe) and relatively large 56Ni production of 0.075 M⊙ from an ∼15 M⊙ red supergiant progenitor typical of other SNe II, or (ii) a relatively compact ∼40 M⊙ star, explosion energy of 1 foe, and 0.08 M⊙ of 56Ni. Both scenarios require additional energy input to explain the late-time light curve, which is consistent with fallback accretion at a rate of ∼0.5 × 10−8 M⊙ s−1. 

   more » « less
3. A JWST Survey of the Supernova Remnant Cassiopeia A

   https://doi.org/10.3847/2041-8213/ad324b  

   Milisavljevic, Dan; Temim, Tea; De_Looze, Ilse; Dickinson, Danielle; Laming, J_Martin; Fesen, Robert; Raymond, John_C; Arendt, Richard_G; Vink, Jacco; Posselt, Bettina; et al (April 2024, The Astrophysical Journal Letters)

   Abstract We present initial results from a James Webb Space Telescope (JWST) survey of the youngest Galactic core-collapse supernova remnant, Cassiopeia A (Cas A), made up of NIRCam and MIRI imaging mosaics that map emission from the main shell, interior, and surrounding circumstellar/interstellar material (CSM/ISM). We also present four exploratory positions of MIRI Medium Resolution Spectrograph integral field unit spectroscopy that sample ejecta, CSM, and associated dust from representative shocked and unshocked regions. Surprising discoveries include (1) a weblike network of unshocked ejecta filaments resolved to ∼0.01 pc scales exhibiting an overall morphology consistent with turbulent mixing of cool, low-entropy matter from the progenitor’s oxygen layer with hot, high-entropy matter heated by neutrino interactions and radioactivity; (2) a thick sheet of dust-dominated emission from shocked CSM seen in projection toward the remnant’s interior pockmarked with small (∼1″) round holes formed by ≲0.″1 knots of high-velocity ejecta that have pierced through the CSM and driven expanding tangential shocks; and (3) dozens of light echoes with angular sizes between ∼0.″1 and 1′ reflecting previously unseen fine-scale structure in the ISM. NIRCam observations place new upper limits on infrared emission (≲20 nJy at 3μm) from the neutron star in Cas A’s center and tightly constrain scenarios involving a possible fallback disk. These JWST survey data and initial findings help address unresolved questions about massive star explosions that have broad implications for the formation and evolution of stellar populations, the metal and dust enrichment of galaxies, and the origin of compact remnant objects. 

   more » « less
4. A successful 3D core-collapse supernova explosion model

   https://doi.org/10.1093/mnras/sty2585  

   Vartanyan, David; Burrows, Adam; Radice, David; Skinner, M Aaron; Dolence, Joshua (September 2018, Monthly Notices of the Royal Astronomical Society)
5. Maven: a multimodal foundation model for supernova science

   https://doi.org/10.1088/2632-2153/ad990d  

   Zhang, Gemma; Helfer, Thomas; Gagliano, Alexander_T; Mishra-Sharma, Siddharth; Ashley_Villar, V. (December 2024, Machine Learning: Science and Technology)

   Abstract A common setting in astronomy is the availability of a small number of high-quality observations, and larger amounts of either lower-quality observations or synthetic data from simplified models. Time-domain astrophysics is a canonical example of this imbalance, with the number of supernovae observed photometrically outpacing the number observed spectroscopically by multiple orders of magnitude. At the same time, no data-driven models exist to understand these photometric and spectroscopic observables in a common context. Contrastive learning objectives, which have grown in popularity for aligning distinct data modalities in a shared embedding space, provide a potential solution to extract information from these modalities. We present Maven, the first foundation model for supernova science. To construct Maven, we first pre-train our model to align photometry and spectroscopy from 0.5 M synthetic supernovae using a contrastive objective. We then fine-tune the model on 4702 observed supernovae from the Zwicky transient facility. Maven reaches state-of-the-art performance on both classification and redshift estimation, despite the embeddings not being explicitly optimized for these tasks. Through ablation studies, we show that pre-training with synthetic data improves overall performance. In the upcoming era of the Vera C. Rubin observatory, Maven will serve as a valuable tool for leveraging large, unlabeled and multimodal time-domain datasets. 

   more » « less