Examinando por Autor "Margutti, Raffaella"

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    A missing-link in the supernova-GRB connection: The case of SN 2012ap
    (Institute of Physics Publishing, 2015-06) Chakraborti, Sayan; Soderberg, Alicia; Chomiuk, Laura; Kamble, Atish; Yadav, Naveen; Ray, Alak; Hurley, Kevin; Margutti, Raffaella; Milisavljevic, Dan; Bietenholz, Michael; Brunthaler, Andreas; Pignata, Giuliano; Pian, Elena; Mazzali, Paolo; Fransson, Claes; Bartel, Norbert; Hamuy, Mario; Levesque, Emily; Macfadyen, Andrew; Dittmann, Jason; Krauss, Miriam; Briggs, M.S.; Connaughton, V.; Yamaoka, K.; Takahashi, T.; Ohno M., Fukazawa; Tashiro, M.; Terada, Y.; Murakami, T.; Goldsten, J.; Barthelmy, S.; Gehrels, N.; Cummings, J.; Krimm, H.; Palmer, D.; Golenetskii, S.; Aptekar, R.; Frederiks, D.; Svinkin, D.; Cline, T.; Mitrofanov, I.G.; Golovin, D.; Litvak, M.L.; Sanin, A.B.; Boynton, W.; Fellows, C.; Harshman, K.; Enos, H.; Kienlin, A. Von; Rau, A.; Zhang, X.; Savchenko, V.
    Gamma-ray bursts (GRBs) are characterized by ultra-relativistic outflows, while supernovae are generally characterized by non-relativistic ejecta. GRB afterglows decelerate rapidly, usually within days, because their low-mass ejecta rapidly sweep up a comparatively larger mass of circumstellar material. However, supernovae with heavy ejecta can be in nearly free expansion for centuries. Supernovae were thought to have non-relativistic outflows except for a few relativistic ones accompanied by GRBs. This clear division was blurred by SN 2009bb, the first supernova with a relativistic outflow without an observed GRB. However, the ejecta from SN 2009bb was baryon loaded and in nearly free expansion for a year, unlike GRBs. We report the first supernova discovered without a GRB but with rapidly decelerating mildly relativistic ejecta, SN 2012ap. We discovered a bright and rapidly evolving radio counterpart driven by the circumstellar interaction of the relativistic ejecta. However, we did not find any coincident GRB with an isotropic fluence of more than one-sixth of the fluence from GRB 980425. This shows for the first time that central engines in SNe Ic, even without an observed GRB, can produce both relativistic and rapidly decelerating outflows like GRBs. © 2015. The American Astronomical Society. All rights reserved.
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    Multi-wavelength observations of supernova 2011ei: time-dependent classification of type iib and ib supernovae and implications for their progenitors
    (2012) Milisavljevic, Dan; Margutti, Raffaella; Soderberg, Alicia M.; Pignata, Giuliano; Chomiuk, Laura; Fesen, Robert A.; Bufano, Filomena; Sanders, Nathan E.; Parrent, Jerod T.; Parker, Stuart; Pickering, Timothy; Buckley, David A. H.; Crawford, Steven M.; Gulbis, Amanda A. S.; Hettlage, Christian; Hooper, Eric; Nordsieck, Kenneth H.; O'Donoghue, Darragh; Husser, Tim-Oliver; Potter, Stephen; Kniazev, Alexei; Kotze, Paul; Romero-Colmenero, Encarni; Vaisanen, Petri; Wolf, Marsha; Bartel, Norbert; Bietenholz, Michael F.; Fransson, Claes; Mazzali, Paolo; Brunthaler, Andreas; Chakraborti, Sayan; Levesque, Emily M.; MacFayden, Andrew; Drescher, Colin; Bock, Greg; Marples, Peter; Anderson, Joseph P.; Benetti, Stefano; Reichart, Daniel; Ivarsen, Kevin
    We present X-ray, UV/optical, and radio observations of the stripped-envelope, core-collapse supernova (SN) 2011ei, one of the least luminous SNe IIb or Ib observed to date. Our observations begin with a discovery within 1 day of explosion and span several months afterward. Early optical spectra exhibit broad, Type II-like hydrogen Balmer profiles that subside rapidly and are replaced by Type Ib-like He-rich features on the timescale of one week. High-cadence monitoring of this transition identifies an absorption feature around 6250 °A to be chiefly due to hydrogen, as opposed to C II, Ne I, or Si II. Similarities between this observed feature and several SNe Ib suggest that hydrogen absorption attributable to a high velocity (& 12, 000 km s−1) H-rich shell is not rare in Type Ib events. Radio observations imply a shock velocity of v 0.13c and a progenitor star mass-loss rate of ˙M 1.4 × 10−5 M⊙ yr−1 (assuming wind velocity vw = 103 km s−1). This is consistent with independent constraints estimated from deep X-ray observations with Swift -XRT and Chandra. We find the multi-wavelength properties of SN2011ei to be consistent with the explosion of a lower-mass (3−4 M⊙), compact (R∗ 1×1011 cm), He core star. The star retained a thin hydrogen envelope at the time of outburst, and was embedded in an inhomogeneous circumstellar wind suggestive of modest episodic mass-loss. We conclude that SN2011ei’s rapid spectral metamorphosis calls attention to time-dependent classifications that bias estimates of explosion rates for a subset of Type IIb and Ib objects. Further, that important information about a progenitor star’s evolutionary state and associated mass-loss in the days to years prior to SN outburst can be inferred from timely multi-wavelength observations.
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    Rubin Observatory LSST Transients and Variable Stars Roadmap
    (Institute of Physics, 2023-10) Hambleton, Kelly M.; Bianco, Federica B.; Street, Rachel; Bell, Keaton; Buckley, David; Graham, Melissa; Hernitschek, Nina; Lund, Michael B.; Mason, Elena; Pepper, Joshua; Prša, Andrej; Rabus, Markus; Raiteri, Claudia M.; Szabó, Róbert; Szkody, Paula; Andreoni, Igor; Antoniucci, Simone; Balmaverde, Barbara; Bellm, Eric; Bonito, Rosaria; Bono, Giuseppe; Botticella, Maria Teresa; Brocato, Enzo; Bricman, Katja Bučar; Cappellaro, Enrico; Carnerero, Maria Isabel; Chornock, Ryan; Clarke, Riley; Cowperthwaite, Phil; Cucchiara, Antonino; D’Ammando, Filippo; Dage, Kristen C.; Dall’Ora, Massimo; Davenport, James R.A.; de Martino, Domitilla; de Somma, Giulia; Criscienzo, Marcella Di; Stefano, Rosanne Di; Drout, Maria; Fabrizio, Michele; Fiorentino, Giuliana; Gandhi, Poshak; Garofalo, Alessia; Giannini, Teresa; Gomboc, Andreja; Greggio, Laura; Hartigan, Patrick; Hundertmark, Markus; Johnson, Elizabeth; Johnson, Michael; Jurkic, Tomislav; Khakpash, Somayeh; Leccia, Silvio; Li, Xiaolong; Magurno, Davide; Malanchev, Konstantin; Marconi, Marcella; Margutti, Raffaella; Marinoni, Silvia; Mauron, Nicolas; Molinaro, Roberto; Möller, Anais; Moniez, Marc; Muraveva, Tatiana; Musella, Ilaria; Ngeow, Chow-Choong; Pastorello, Andrea; Petrecca, Vincenzo; Piranomonte, Silvia; Ragosta, Fabio; Reguitti, Andrea; Righi, Chiara; Ripepi, Vincenzo; Rivera Sandoval, Liliana; Stassun, Keivan G.; Stroh, Michael; Terreran, Giacomo; Trimble, Virginia; Tsapras, Yiannis; van Velzen, Sjoert; Venuti, Laura; Vink, Jorick S.
    The Vera C. Rubin Legacy Survey of Space and Time (LSST) holds the potential to revolutionize time domain astrophysics, reaching completely unexplored areas of the Universe and mapping variability time scales from minutes to a decade. To prepare to maximize the potential of the Rubin LSST data for the exploration of the transient and variable Universe, one of the four pillars of Rubin LSST science, the Transient and Variable Stars Science Collaboration, one of the eight Rubin LSST Science Collaborations, has identified research areas of interest and requirements, and paths to enable them. While our roadmap is ever-evolving, this document represents a snapshot of our plans and preparatory work in the final years and months leading up to the survey’s first light. © 2023 Institute of Physics Publishing. All rights reserved.