Ultraviolet spectroscopy of type iib supernovae

Diversity and the impact of circumstellar material

Sagi Ben-Ami, Stephan Hachinger, Avishay Gal-Yam, Paolo A. Mazzali, Alexei V. Filippenko, Assaf Horesh, Thomas Matheson, Maryam Modjaz, Daniel N. Sauer, Jeffrey M. Silverman, Nathan Smith, Ofer Yaron

    Research output: Contribution to journalArticle

    Abstract

    ABSTRACT We present new Hubble Space Telescope (HST) multi-epoch ultraviolet (UV) spectra of the bright Type IIb SN 2013df, and undertake a comprehensive analysis of the set of four SNe IIb for which HST UV spectra are available (SN 1993J, SN 2001ig, SN 2011dh, and SN 2013df). We find strong diversity in both continuum levels and line features among these objects. We use radiative-transfer models that fit the optical part of the spectrum well, and find that in three of these four events we see a UV continuum flux excess, apparently unaffected by line absorption. We hypothesize that this emission originates above the photosphere, and is related to interaction with circumstellar material (CSM) located in close proximity to the SN progenitor. In contrast, the spectra of SN 2001ig are well fit by single-temperature models, display weak continuum and strong reverse-fluorescence features, and are similar to spectra of radioactive <sup>56</sup>Ni-dominated SNe Ia. A comparison of the early shock-cooling components in the observed light curves with the UV continuum levels which we assume trace the strength of CSM interaction suggests that events with slower cooling have stronger CSM emission. The radio emission from events having a prominent UV excess is perhaps consistent with slower blast-wave velocities, as expected if the explosion shock was slowed down by the CSM that is also responsible for the strong UV, but this connection is currently speculative as it is based on only a few events.

    Original languageEnglish (US)
    Article number40
    Pages (from-to)1-11
    Number of pages11
    JournalAstrophysical Journal
    Volume803
    Issue number1
    DOIs
    StatePublished - Apr 10 2015

    Fingerprint

    ultraviolet spectroscopy
    supernovae
    spectroscopy
    continuums
    ultraviolet spectra
    Hubble Space Telescope
    shock
    cooling
    blasts
    photosphere
    radio emission
    radiative transfer
    light curve
    explosions
    proximity
    time measurement
    interactions
    wave velocity
    explosion
    fluorescence

    ASJC Scopus subject areas

    • Space and Planetary Science
    • Astronomy and Astrophysics

    Cite this

    Ben-Ami, S., Hachinger, S., Gal-Yam, A., Mazzali, P. A., Filippenko, A. V., Horesh, A., ... Yaron, O. (2015). Ultraviolet spectroscopy of type iib supernovae: Diversity and the impact of circumstellar material. Astrophysical Journal, 803(1), 1-11. [40]. https://doi.org/10.1088/0004-637X/803/1/40

    Ultraviolet spectroscopy of type iib supernovae : Diversity and the impact of circumstellar material. / Ben-Ami, Sagi; Hachinger, Stephan; Gal-Yam, Avishay; Mazzali, Paolo A.; Filippenko, Alexei V.; Horesh, Assaf; Matheson, Thomas; Modjaz, Maryam; Sauer, Daniel N.; Silverman, Jeffrey M.; Smith, Nathan; Yaron, Ofer.

    In: Astrophysical Journal, Vol. 803, No. 1, 40, 10.04.2015, p. 1-11.

    Research output: Contribution to journalArticle

    Ben-Ami, S, Hachinger, S, Gal-Yam, A, Mazzali, PA, Filippenko, AV, Horesh, A, Matheson, T, Modjaz, M, Sauer, DN, Silverman, JM, Smith, N & Yaron, O 2015, 'Ultraviolet spectroscopy of type iib supernovae: Diversity and the impact of circumstellar material', Astrophysical Journal, vol. 803, no. 1, 40, pp. 1-11. https://doi.org/10.1088/0004-637X/803/1/40
    Ben-Ami S, Hachinger S, Gal-Yam A, Mazzali PA, Filippenko AV, Horesh A et al. Ultraviolet spectroscopy of type iib supernovae: Diversity and the impact of circumstellar material. Astrophysical Journal. 2015 Apr 10;803(1):1-11. 40. https://doi.org/10.1088/0004-637X/803/1/40
    Ben-Ami, Sagi ; Hachinger, Stephan ; Gal-Yam, Avishay ; Mazzali, Paolo A. ; Filippenko, Alexei V. ; Horesh, Assaf ; Matheson, Thomas ; Modjaz, Maryam ; Sauer, Daniel N. ; Silverman, Jeffrey M. ; Smith, Nathan ; Yaron, Ofer. / Ultraviolet spectroscopy of type iib supernovae : Diversity and the impact of circumstellar material. In: Astrophysical Journal. 2015 ; Vol. 803, No. 1. pp. 1-11.
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