Massive stars exploding in a He-rich circumstellar medium - IV. Transitional type Ibn supernovae

A. Pastorello, S. Benetti, P. J. Brown, D. Y. Tsvetkov, C. Inserra, S. Taubenberger, L. Tomasella, M. Fraser, D. J. Rich, M. T. Botticella, F. Bufano, E. Cappellaro, M. Ergon, E. S. Gorbovskoy, A. Harutyunyan, F. Huang, R. Kotak, V. M. Lipunov, L. Magill, M. MiluzioN. Morrell, P. Ochner, S. J. Smartt, J. Sollerman, S. Spiro, M. D. Stritzinger, M. Turatto, S. Valenti, X. Wang, D. E. Wright, V. V. Yurkov, L. Zampieri, L. Zhang

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We present ultraviolet, optical and near-infrared data of the Type Ibn supernovae (SNe) 2010al and 2011hw. SN 2010al reaches an absolute magnitude at peak of MR = -18.86 ± 0.21. Its early light curve shows similarities with normal SNe Ib, with a rise to maximum slower than most SNe Ibn. The spectra are dominated by a blue continuum at early stages, with narrow P-Cygni He I lines indicating the presence of a slow-moving, He-rich circumstellar medium. At later epochs, the spectra well match those of the prototypical SN Ibn 2006jc, although the broader lines suggest that a significant amount of He was still present in the stellar envelope at the time of the explosion. SN 2011hw is somewhat different. It was discovered after the first maximum, but the light curve shows a double peak. The absolute magnitude at discovery is similar to that of the second peak (MR = -18.59 ± 0.25), and slightly fainter than the average of SNe Ibn. Though the spectra of SN 2011hw are similar to those of SN 2006jc, coronal lines and narrow Balmer lines are clearly detected. This indicates substantial interaction of the SN ejecta with He-rich, but not H-free, circumstellar material. The spectra of SN 2011hw suggest that it is a transitional SN Ibn/IIn event similar to SN 2005la. While for SN 2010al the spectrophotometric evolution favours a H-deprived Wolf-Rayet progenitor (of WN-type), we agree with the conclusion of Smith et al. that the precursor of SN 2011hw was likely in transition from a luminous blue variable to an early Wolf-Rayet (Ofpe/WN9) stage.

Original languageEnglish (US)
Pages (from-to)1921-1940
Number of pages20
JournalMonthly Notices of the Royal Astronomical Society
Issue number2
StatePublished - May 11 2015

Bibliographical note

Funding Information:
AP thanks Elia Cozzi, Rafael Benavides and Joseph Brimacombe for kindly providing their observations of SN 2010al for this study, and M. L. Pumo for useful discussions. We would like to thank the anonymous referee for providing us with constructive comments and suggestions. AP, EC, SB, MLP, AH, LT and MT are partially supported by the PRIN-INAF 2011 with the project Transient Universe: from ESO Large to PESSTO. DYT is partly supported by the Russian Foundation for Basic Research (project No. 13-02-92119). FB acknowledges support from FONDECYT through Postdoctoral grant 3120227 and by the Millennium Center for Supernova Science through grant P10-064-F (funded by Programa Bicentenario de Ciencia y Tecnología de CONICYT and Programa Iniciativa Científica Milenio de MIDEPLAN). ST acknowledges support by the TransregionalCollaborativeResearch CentreTRR33 of the German Research Foundation. MDS gratefully acknowledges generous support provided by the Danish Agency for Science and Technology and Innovation realized through a Sapere Aude Level 2 grant. XW is supported by the Major State Basic Research Development Programme (2013CB834903), the National Natural Science Foundation of China (NSFC grants 11073013, 11178003, 11325313) and the Foundation of Tsinghua University (2011Z02170) This work is supported in part under grant number 1108890 from the US National Science Foundation and is partly supported by the European Union FP7 programme through ERC grant number 320360. This material is based upon work supported by NSF under grants AST-0306969, AST-0607438 and AST-1008343. The MASTER network has made use of equipment acquired through the Development Programme for Lomonosov Moscow State University, and was also supported by a grant in the form of a subsidy from the Ministry of Education and Science of the Russian Federation (agreement of August 27, 2012, No. 8415) and by the Dinastiya Foundation for Non-Commercial Programmes. The work is supported by the Russian Foundation of Fundamental Research, grant RFFI 14-02-31546. This work is partially based on observations of the European supernova collaboration involved in the ESO-NTT large programme 184.D-1140 led by SB. It is also based on observations made with ESO VLT Telescopes at the Paranal Observatory under programme IDs 084.D-0265 and 085.D-0701 (PI. SB). The manuscript includes data obtained at the Large Binocular Telescope of the Mount Graham International Observatory. The LBT is an international collaboration among institutions in the United States, Italy and Germany. LBT Corporation partners are: The University of Arizona on behalf of the Arizona university system; Istituto Nazionale di Astrofisica, Italy; LBT Beteiligungsgesellschaft, Germany, representing the Max-Planck Society, the Astrophysical Institute Potsdam and Heidelberg University; The Ohio State University, and The Research Corporation, on behalf of The University of Notre Dame, University of Minnesota and University of Virginia. This paper is based on observations made with the Italian TNG operated on the island of La Palma by the Fundación Galileo Galilei of the INAF (Istituto Nazionale di Astrofisica). It is also based on observations made with the LT operated on the island of La Palma at the Spanish Observatorio del Roque de los Muchachos of the Instituto de Astrofisica de Canarias; the WHT operated on the island of La Palma by the Isaac Newton Group in the Spanish Observatorio del Roque de los Muchachos of the Instituto de Astrofà sica de Canarias; the NOT, operated on the island of La Palma jointly by Denmark, Finland, Iceland, Norway and Sweden, in the Spanish Observatorio del Roque de los Muchachos of the Instituto de Astrof ísica de Canarias; the 0.80m Tsinghua-NAOC Telescope (TNT) in the Xinglong Observatory of NAOC; the 2.2m Telescope of the Centro Astronómico Hispano Alemán (CAHA) at Calar Alto, operated jointly by the Max-Planck Institut für Astronomie and the Instituto de Astrofísica de Andalucía (CSIC); the 1.82m Copernico Telescope and the 67/92-cm Schmidt Telescope of thObservatory; the 2-m Faulkes Telescope North at Haleakala Observatory (Hawaii, US). This work makes use of observations from the LCOGT network. This publication makes use of data products from the Two Micron All Sky Survey, which is a joint project of the University of Massachusetts and the Infrared Processing and Analysis Center/ California Institute of Technology, funded by the National Aeronautics and Space Administration and the National Science Foundation.

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  • Supernovae: general
  • Supernovae: individual: SN 2000er
  • Supernovae: individual: SN 2005la
  • Supernovae: individual: SN 2006jc
  • Supernovae: individual: SN 2010al
  • Supernovae: individual: SN 2011hw


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