title: Supernovae. ⁴⁴Ti gamma-ray emission lines from SN1987A reveal an asymmetric explosion.
abstract: In core-collapse supernovae, titanium-44 ((44)Ti) is produced in the innermost ejecta, in the layer of material directly on top of the newly formed compact object. As such, it provides a direct probe of the supernova engine. Observations of supernova 1987A (SN1987A) have resolved the 67.87- and 78.32-kilo-electron volt emission lines from decay of (44)Ti produced in the supernova explosion. These lines are narrow and redshifted with a Doppler velocity of ~700 kilometers per second, direct evidence of large-scale asymmetry in the explosion.
authors.affiliation: Space Sciences Laboratory, University of California, Berkeley, CA 94720, USA. boggs@berkeley.edu.
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authors.lastname: Boggs
authors.affiliation: Cahill Center for Astronomy and Astrophysics, California Institute of Technology, Pasadena, CA 91125, USA.
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authors.affiliation: Cahill Center for Astronomy and Astrophysics, California Institute of Technology, Pasadena, CA 91125, USA.
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authors.affiliation: Cahill Center for Astronomy and Astrophysics, California Institute of Technology, Pasadena, CA 91125, USA.
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authors.affiliation: Space Sciences Laboratory, University of California, Berkeley, CA 94720, USA.
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authors.affiliation: CCS-2, Los Alamos National Laboratory, Los Alamos, NM 87545, USA.
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authors.affiliation: Physics Department, NC State University, Raleigh, NC 27695, USA.
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authors.affiliation: Department of Physics, Durham University, Durham DH1 3LE, UK.
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authors.affiliation: Department of Physics, McGill University, Rutherford Physics Building, Montreal, Quebec H3A 2T8, Canada.
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authors.affiliation: Université de Toulouse, UPS-OMP, IRAP, Toulouse, France. CNRS, Institut de Recherche en Astrophysique et Planétologie, 9 Av. colonel Roche, BP 44346, F-31028 Toulouse Cedex 4, France.
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authors.affiliation: Space Sciences Laboratory, University of California, Berkeley, CA 94720, USA. Lawrence Livermore National Laboratory, Livermore, CA 94550, USA.
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authors.affiliation: Cahill Center for Astronomy and Astrophysics, California Institute of Technology, Pasadena, CA 91125, USA.
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authors.affiliation: Cahill Center for Astronomy and Astrophysics, California Institute of Technology, Pasadena, CA 91125, USA.
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authors.affiliation: Cahill Center for Astronomy and Astrophysics, California Institute of Technology, Pasadena, CA 91125, USA.
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authors.affiliation: Agenzia Spaziale Italiana (ASI) Science Data Center, Via del Politecnico snc I-00133, Roma, Italy. INAF - Osservatorio Astronomico di Roma, via di Frascati 33, I-00040 Monteporzio, Italy.
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authors.affiliation: Lawrence Livermore National Laboratory, Livermore, CA 94550, USA.
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authors.affiliation: Agenzia Spaziale Italiana (ASI) Science Data Center, Via del Politecnico snc I-00133, Roma, Italy. INAF - Osservatorio Astronomico di Roma, via di Frascati 33, I-00040 Monteporzio, Italy.
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