Browsing by Author "Barna, Barnabas"

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    Ground-based and JWST Observations of SN 2022pul. I. Unusual Signatures of Carbon, Oxygen, and Circumstellar Interaction in a Peculiar Type Ia Supernova
    (2024) Siebert, Matthew R.; Kwok, Lindsey A.; Johansson, Joel; Jha, Saurabh W.; Blondin, Stephane; Dessart, Luc; Foley, Ryan J.; Hillier, D. John; Larison, Conor; Pakmor, Ruediger; Temim, Tea; Andrews, Jennifer E.; Auchettl, Katie; Badenes, Carles; Barna, Barnabas; Bostroem, K. Azalee; Brenner Newman, Max J.; Brink, Thomas G.; Bustamante-Rosell, Maria Jose; Camacho-Neves, Yssavo; Clocchiatti, Alejandro; Coulter, David A.; Davis, Kyle W.; Deckers, Maxime; Dimitriadis, Georgios; Dong, Yize; Farah, Joseph; Filippenko, Alexei V.; Floers, Andreas; Fox, Ori D.; Garnavich, Peter; Gonzalez, Estefania Padilla; Graur, Or; Hambsch, Franz-Josef; Hosseinzadeh, Griffin; Howell, D. Andrew; Hughes, John P.; Kerzendorf, Wolfgang E.; Le Saux, Xavier K.; Maeda, Keiichi; Maguire, Kate; McCully, Curtis; Mihalenko, Cassidy; Newsome, Megan; O'Brien, John T.; Pearson, Jeniveve; Pellegrino, Craig; Pierel, Justin D. R.; Polin, Abigail; Rest, Armin; Rojas-Bravo, Cesar; Sand, David J.; Schwab, Michaela; Shahbandeh, Melissa; Shrestha, Manisha; Smith, Nathan; Strolger, Louis-Gregory; Szalai, Tamas; Taggart, Kirsty; Terreran, Giacomo; Terwel, Jacco H.; Tinyanont, Samaporn; Valenti, Stefano; Vinko, Jozsef; Wheeler, J. Craig; Yang, Yi; Zheng, Weikang; Ashall, Chris; DerKacy, James M.; Galbany, Lluis; Hoeflich, Peter; Hsiao, Eric; de Jaeger, Thomas; Lu, Jing; Maund, Justyn; Medler, Kyle; Morrell, Nidia; Shappee, Benjamin J.; Stritzinger, Maximilian; Suntzeff, Nicholas; Tucker, Michael; Wang, Lifan
    Nebular-phase observations of peculiar Type Ia supernovae (SNe Ia) provide important constraints on progenitor scenarios and explosion dynamics for both these rare SNe and the more common, cosmologically useful SNe Ia. We present observations from an extensive ground- and space-based follow-up campaign to characterize SN 2022pul, a super-Chandrasekhar mass SN Ia (alternatively "03fg-like" SN), from before peak brightness to well into the nebular phase across optical to mid-infrared (MIR) wavelengths. The early rise of the light curve is atypical, exhibiting two distinct components, consistent with SN Ia ejecta interacting with dense carbon-oxygen (C/O)-rich circumstellar material (CSM). In the optical, SN 2022pul is most similar to SN 2012dn, having a low estimated peak luminosity (M B = -18.9 mag) and high photospheric velocity relative to other 03fg-like SNe. In the nebular phase, SN 2022pul adds to the increasing diversity of the 03fg-like subclass. From 168 to 336 days after peak B-band brightness, SN 2022pul exhibits asymmetric and narrow emission from [O i] lambda lambda 6300, 6364 (FWHM approximate to 2000 km s-1), strong, broad emission from [Ca ii] lambda lambda 7291, 7323 (FWHM approximate to 7300 km s-1), and a rapid Fe iii to Fe ii ionization change. Finally, we present the first ever optical-to-MIR nebular spectrum of an 03fg-like SN Ia using data from JWST. In the MIR, strong lines of neon and argon, weak emission from stable nickel, and strong thermal dust emission (with T approximate to 500 K), combined with prominent [O i] in the optical, suggest that SN 2022pul was produced by a white dwarf merger within C/O-rich CSM.
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    SN 2020udy: A New Piece of the Homogeneous Bright Group in the Diverse Iax Subclass
    (2024) Singh, Mridweeka; Sahu, Devendra K.; Barna, Barnabas; Gangopadhyay, Anjasha; Dastidar, Raya; Teja, Rishabh Singh; Misra, Kuntal; Howell, D. Andrew; Wang, Xiaofeng; Mo, Jun; Yan, Shengyu; Hiramatsu, Daichi; Pellegrino, Craig; Anupama, G. C.; Joshi, Arti; Bostroem, K. Azalee; Burke, Jamison; McCully, Curtis; Subramanian, Rama, V; Li, Gaici; Xi, Gaobo; Li, Xin; Li, Zhitong; Srivastav, Shubham; Im, Hyobin; Dutta, Anirban
    We present optical observations and analysis of the bright type Iax supernova SN 2020udy hosted by NGC 0812. The evolution of the light curve of SN 2020udy is similar to that of other bright type Iax SNe. Analytical modeling of the quasi-bolometric light curves of SN 2020udy suggests that 0.08 +/- 0.01 M circle dot of 56Ni would have been synthesized during the explosion. The spectral features of SN 2020udy are similar to those of the bright members of type Iax class, showing a weak Si ii line. The late-time spectral sequence is mostly dominated by iron group elements with broad emission lines. Abundance tomography modeling of the spectral time series of SN 2020udy using TARDIS indicates stratification in the outer ejecta; however, to confirm this, spectral modeling at a very early phase is required. After maximum light, uniform mixing of chemical elements is sufficient to explain the spectral evolution. Unlike in the case of normal type Ia SNe, the photospheric approximation remains robust until +100 days, requiring an additional continuum source. Overall, the observational features of SN 2020udy are consistent with the deflagration of a carbon-oxygen white dwarf.