SN 2006tf: Precursor Eruptions and the Optically Thick Regime of Extremely Luminous Type IIn Supernovae

By N. Smith, Ryan Chornock, Weidong Li, M. Ganeshalingam, J. Silverman, R. Foley, A. Filippenko, A. Barth. 2008

199 citations recorded by the source corpus.

SN 2006tf is the third most luminous supernova (SN) discovered so far, after SN 2005ap and SN 2006gy. SN 2006tf is valuable because it provides a link between two regimes: (1) luminous Type IIn supernovae powered by emission directly from interaction with circumstellar material (CSM), and (2) the most extremely luminous SNe where the CSM interaction is so optically thick that energy must diffuse out from an opaque shocked shell. As SN 2006tf evolves, it slowly transitions from the second to the first regime as the clumpy shell becomes more porous. This link suggests that the range in properties of the most luminous SNe is largely determined by the density and speed of hydrogen-rich material ejected shortly before they explode. The total energy radiated by SN 2006tf was at least 7 × 1050 ergs. If the bulk of this luminosity came from the thermalization of shock kinetic energy, then the star needs to have ejected ~18 M☉ in the 4-8 yr before core collapse, and another 2-6 M☉ in the decades before that. A Type Ia explosion is therefore excluded. From the Hα emission-line profile, we derive a blast wave speed of 2000 km s−1 that does not decelerate, and from the narrow P Cygni absorption from preshock gas we deduce that the progenitor's wind speed was ~190 km s−1. This is reminiscent of the wind speeds of luminous blue variables (LBVs), but not of red supergiants or Wolf-Rayet stars. We propose that like SN 2006gy, SN 2006tf marked the death of a very massive star that retained a hydrogen envelope until the end of its life and suffered extreme LBV-like mass loss in the decades before it exploded.

Subfields: Astronomy and Astrophysics

View Paper: https://www.semanticscholar.org/paper/31385d54e8b82f1180754862d783045c444c2ea6

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In Astronomy and Astrophysics

1. N. Smith
2. S. Smartt
3. A. Filippenko
4. E. Berger
5. Ryan Chornock
6. B. Metzger
7. E. Quataert
8. T. Thompson

Citations in the corpus

• Observed Fractions of Core-Collapse Supernova Types and Initial Masses of their Single and Binary Progenitor Stars (2010, background): “…even among the subclass, with the faintest SNe IIn like SN 2005ip looking basically like an SN II-L with strong narrow emission lines (Smith et al. 2009b), whereas the CSM is opaque and qualitatively changes the SN in more luminous SNe IIn such as SN 2006tf and SN 2006gy (Smith et al. 2008b).”
• On the diversity of superluminous supernovae: ejected mass as the dominant factor (2015, background): “Quite a few such objects are now known – e.g. SNe 2006tf (Smith et al. 2008), 2008fz (Drake et al. 2010), 2008am (Chatzopoulos et al. 2011) and 2003ma (Rest et al. 2011) – and these are quite correctly dubbed ‘SLSNe IIn’, by analogy with the fainter SNe IIn, which are hydrogen-rich SNe showing…”
• PREPARING FOR AN EXPLOSION: HYDRODYNAMIC INSTABILITIES AND TURBULENCE IN PRESUPERNOVAE (2013, background): “Progenitor star detections We now have four directly detected quiescent progenitors of SNe IIn with rough mass estimates.”
• ANALYTICAL LIGHT CURVE MODELS OF SUPERLUMINOUS SUPERNOVAE: χ2-MINIMIZATION OF PARAMETER FITS (2013, methodology): “SN 2006tf exhibited spectroscopic similarities with other SLSNe such as SN 2006gy (Smith et al. 2007) and SN 2008am (Chatzopoulos et al. 2011) and, given the duration of its observed LC, it is considered a classic example of a Type IIn event associated with a massive progenitor (Smith et al. 2008).”
• CALTECH CORE-COLLAPSE PROJECT (CCCP) OBSERVATIONS OF TYPE IIn SUPERNOVAE: TYPICAL PROPERTIES AND IMPLICATIONS FOR THEIR PROGENITOR STARS (2010, background): “Over the years, a specific model has emerged, which describes the properties of SNe IIn as a result from a combination of emission from several physically distinct regions (see Smith et al. 2008 for a recent description).”
• HIGH-DENSITY CIRCUMSTELLAR INTERACTION IN THE LUMINOUS TYPE IIn SN 2010jl: THE FIRST 1100 DAYS (2013, background): “Also in objects where there indeed are strong indications for dust formation, like SN 1998S and SN 2006jc, the line profiles are less centrally peaked and more irregular (Leonard et al. 2000; Pozzo et al. 2004; Fransson et al. 2005; Smith et al. 2008a).”
• The Proto-Magnetar Model for Gamma-Ray Bursts (2010, background): “A number of core-collapse SNe have been recently discovered that are unusually bright and/or optically-energetic (e.g. Ofek et al. 2007; Smith et al. 2007; Smith et al. 2008; Quimby et al. 2007; Rest et al. 2009; Gal-Yam et al. 2007; Quimby et al. 2009).”
• Nearby Supernova Rates from the Lick Observatory Supernova Search. II. The Observed Luminosity Functions and Fractions of Supernovae in a Complete Sample (2010, background): “…several extremely luminous CC SNe have been reported, including SN 2003ma (Rest et al. 2009), SN 2005ap (Quimby et al. 2007), SN 2006gy (Smith et al. 2007; Ofek et al. 2007), SN 2006tf (Smith et al. 2008), SN 2008es (Miller et al. 2009; Gezari et al. 2009), and SN 2008fz (Drake et al. 2010).”
• SPECTRAL EVOLUTION OF THE EXTRAORDINARY TYPE IIn SUPERNOVA 2006gy (2009, methodology): “The effective value of RBB begins to fall, not because the radius is actually decreasing, but because the CDS is fragmented and is becoming progressively more transparent (Smith et al. 2008a).”
• RED SUPERGIANTS AS POTENTIAL TYPE IIn SUPERNOVA PROGENITORS: SPATIALLY RESOLVED 4.6 μm CO EMISSION AROUND VY CMa AND BETELGEUSE (2008, background): “This is more than two orders of magnitude below typical estimates of w for SNe IIn (e.g., Chugai & Danziger 1994) and four orders of magnitude below overluminous SNe IIn like 2006tf (Smith et al. 2008).”
• Mass Loss: Its Effect on the Evolution and Fate of High-Mass Stars (2014, background): “…recently, pre-SN eruptive mass loss and connections to LBVs were mostly hypothetical, limited to (reasonable) conjectures supported by the circumstantial evidence that something must deposit a large mass of outflowing H-rich CSM so close to the star (Chugai et al. 2004, Smith et al. 2008, 2010b).”
• Rates of superluminous supernovae at z ∼ 0.2 (2013, background): “It is interesting to note that if the peak magnitude of SN2006gy is corrected for host absorption, then the combined distribution of SLSN-I and SLSN-II peaks sharply at M ∼ −21.8 with SN2006tf the only SLSN-II falling below2.”
• Luminous blue variable eruptions and related transients: diversity of progenitors and outburst properties (2010, background): “We therefore adopt m−M=30.0 mag, and also correct the light curve for a Galactic extinction value of AB=0.27 mag (the B-band extinction is probably most appropriate for the photographc magnitudes in the light curve), making the peak absolute magnitude roughly −17.8, far exceeding any other SN impost”
• GENERALIZED SEMI-ANALYTICAL MODELS OF SUPERNOVA LIGHT CURVES (2011, methodology): “A rich database of optical spectra were obtained for SLSN 2006gy (Smith et al. 2007, 2008, 2010) that provides an extensive record of its spectral evolution.”
• The Unprecedented Third Outburst of SN 2009ip: A Luminous Blue Variable Becomes a Supernova (2012, background): “While LBVs provide the only known precedent for the eruptive pre-SN mass loss needed to make luminous SNe IIn (e.g., Smith et al. 2010a, 2008a), this suggestion has been controversial because it directly contradicts current expectations of standard stellar evolution models (Heger et al. 2003;…”
• Carnegie Supernova Project: Observations of Type IIn supernovae ⋆ (2013, background): “This was discussedby Smith et al. (2008), where they present SN 2006tf.”
• Progenitors of Core-Collapse Supernovae (2009, background): “Thus Smith et al. (2008) propose that such dense shells were created in LBV-like giant eruptions and mass ejections, within a few years (perhaps up to decades) before final explosion.”