Hypernovae: SNe 1997ef, 1998bw, and 1997cy

We discuss the properties of the very energetic Type Ic supernovae (SNe Ic) 1998bw and 1997ef, and of Type IIn supernova (SN IIn) 1997cy. SNe Ic 1998bw and 1997ef are characterized by their large luminosity and very broad spectral features. Their observed properties can be explained if they are very energetic SN explosions (EK ≳ 1 × 1052 erg), originating probably from the core collapse of the bare C+O cores of massive stars (~ 30–40M⊙). At late times, both the light curve and the spectra suggest that the explosion may have been asymmetric; this may help us understand the claimed connection with GRBs. Type IIn SN 1997cy is even more luminous than SN 998bw, and the light curve declines more slowly than the 56Co decay. We model such a light curve with circumstellar interaction, which requires the explosion energy of ~ 5 × 1052 erg. Because these kinetic energies of explosion are much larger than in normal core-collapse SNe, we call objects like these SNe “hypernovae”.

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Core-Collape Supernova Progenitors: Light-Curve and Stellar-Evolution Models

Proceedings of the International Astronomical Union ◽

10.1017/s1743921317003271 ◽

2016 ◽

Vol 12 (S329) ◽

pp. 25-31

Author(s):

Melina C. Bersten

Keyword(s):

Light Curve ◽

Stellar Evolution ◽

Light Curves ◽

Current Understanding ◽

Explosion Energy ◽

Core Collapse ◽

Powerful Method ◽

Direct Identification ◽

Normal Core ◽

Hydrodynamical Modeling

AbstractA very active area of research in the field of core-collapse supernovae (SNe) is the study of their progenitors and the links with different subtypes. Direct identification using pre- and post-SN images is a powerful method but it can only be applied to the most nearby events. An alternative method is the hydrodynamical modeling of SN light curves and expansion velocities, which can serve to characterize the progenitor (e.g. mass and radius) and the explosion itself (e.g. explosion energy and radioactive yields). This latter methodology is particularly powerful when combined with stellar evolution calculations. We review our current understanding of the properties of normal core-collapse SNe based chiefly on these two methods.

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Luminous supernovae associated with ultra-long gamma-ray bursts from hydrogen-free progenitors extended by pulsational pair-instability

Astronomy and Astrophysics ◽

10.1051/0004-6361/202038903 ◽

2020 ◽

Vol 641 ◽

pp. L10

Author(s):

Takashi J. Moriya ◽

Pablo Marchant ◽

Sergei I. Blinnikov

Keyword(s):

Light Curve ◽

Energy Input ◽

Gamma Ray ◽

Gamma Ray Bursts ◽

Core Collapse ◽

Decay Energy ◽

Slow Cooling ◽

Gamma Ray Burst ◽

The Core ◽

Optical Light Curve

We show that the luminous supernovae associated with ultra-long gamma-ray bursts can be related to the slow cooling from the explosions of hydrogen-free progenitors that are extended by pulsational pair-instability. We have recently shown that some rapidly-rotating hydrogen-free gamma-ray burst progenitors that experience pulsational pair-instability can keep an extended structure caused by pulsational pair-instability until the core collapse. These types of progenitors have large radii exceeding 10 R⊙ and they sometimes reach beyond 1000 R⊙ at the time of the core collapse. They are, therefore, promising progenitors of ultra-long gamma-ray bursts. Here, we perform light-curve modeling of the explosions of one extended hydrogen-free progenitor with a radius of 1962 R⊙. The progenitor mass is 50 M⊙ and 5 M⊙ exists in the extended envelope. We use the one-dimensional radiation hydrodynamics code STELLA in which the explosions are initiated artificially by setting given explosion energy and 56Ni mass. Thanks to the large progenitor radius, the ejecta experience slow cooling after the shock breakout and they become rapidly evolving (≲10 days), luminous (≳1043 erg s−1) supernovae in the optical even without energy input from the 56Ni nuclear decay when the explosion energy is more than 1052 erg. The 56Ni decay energy input can affect the light curves after the optical light-curve peak and make the light-curve decay slowly when the 56Ni mass is around 1 M⊙. They also have a fast photospheric velocity above 10 000 km s−1 and a hot photospheric temperature above 10 000 K at around the peak luminosity. We find that the rapid rise and luminous peak found in the optical light curve of SN 2011kl, which is associated with the ultra-long gamma-ray burst GRB 111209A, can be explained as the cooling phase of the extended progenitor. The subsequent slow light-curve decline can be related to the 56Ni decay energy input. The ultra-long gamma-ray burst progenitors we proposed recently can explain both the ultra-long gamma-ray burst duration and the accompanying supernova properties. When the gamma-ray burst jet is off-axis or choked, the luminous supernovae could be observed as fast blue optical transients without accompanying gamma-ray bursts.

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Type Ic supernova of a 22 M⊙ progenitor

Monthly Notices of the Royal Astronomical Society ◽

10.1093/mnras/staa123 ◽

2020 ◽

Vol 492 (3) ◽

pp. 4369-4385 ◽

Cited By ~ 4

Author(s):

Jacob Teffs ◽

Thomas Ertl ◽

Paolo Mazzali ◽

Stephan Hachinger ◽

Thomas Janka

Keyword(s):

Spectral Properties ◽

Massive Stars ◽

Element Distribution ◽

Light Curves ◽

Explosion Energy ◽

Core Collapse ◽

Narrow Line ◽

Average Value ◽

Wide Range ◽

Hydrogen Lines

ABSTRACT Type Ic supernovae (SNe Ic) are a sub-class of core-collapse SNe that exhibit no helium or hydrogen lines in their spectra. Their progenitors are thought to be bare carbon–oxygen cores formed during the evolution of massive stars that are stripped of their hydrogen and helium envelopes sometime before collapse. SNe Ic present a range of luminosities and spectral properties, from luminous GRB-SNe with broad-lined spectra to less luminous events with narrow-line spectra. Modelling SNe Ic reveals a wide range of both kinetic energies, ejecta masses, and 56Ni masses. To explore this diversity and how it comes about, light curves and spectra are computed from the ejecta following the explosion of an initially 22 M⊙ progenitor that was artificially stripped of its hydrogen and helium shells, producing a bare CO core of ∼5 M⊙, resulting in an ejected mass of ∼4 M⊙, which is an average value for SNe Ic. Four different explosion energies are used that cover a range of observed SNe. Finally, 56Ni and other elements are artificially mixed in the ejecta using two approximations to determine how element distribution affects light curves and spectra. The combination of different explosion energy and degree of mixing produces spectra that roughly replicate the distribution of near-peak spectroscopic features of SNe Ic. High explosion energies combined with extensive mixing can produce red, broad-lined spectra, while minimal mixing and a lower explosion energy produce bluer, narrow-lined spectra.

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Progenitor for Type Ic Supernova 2007bi

Proceedings of the International Astronomical Union ◽

10.1017/s1743921312013671 ◽

2011 ◽

Vol 7 (S279) ◽

pp. 427-428

Author(s):

Takashi Yoshida ◽

Hideyuki Umeda

Keyword(s):

Light Curve ◽

Mass Loss ◽

Loss Rate ◽

Main Sequence ◽

Massive Stars ◽

Mass Loss Rate ◽

Mass Range ◽

Stellar Mass ◽

Core Collapse ◽

Core Collapse Supernova

AbstractWe investigate the evolution of very massive stars with Z = 0.2 Z⊙ to constrain the progenitor of the extremely luminous Type Ic SN 2007bi. In order to reproduce the 56Ni amount produced in SN 2007bi, the range of the stellar mass at the zero-age main-sequence is expected to be 515 - 575M⊙ for pair-instability supernova and 110 - 280M⊙ for core-collapse supernova. Uncertainty in the mass loss rate affects the mass range appropriate for the explosion of SN 2007bi. A core-collapse supernova of a WO star evolved from a 110 M⊙ star produces sufficient radioactive 56Ni to reproduce the light curve of SN 2007bi.

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Recent Observations of GRB-Supernovae

Proceedings of the International Astronomical Union ◽

10.1017/s1743921312012732 ◽

2011 ◽

Vol 7 (S279) ◽

pp. 83-90

Author(s):

Bethany Elisa Cobb

Keyword(s):

Massive Stars ◽

Core Collapse ◽

X Ray ◽

The Core ◽

Long Duration

AbstractThe GRB-SNe connection has been strengthened since 2008 by the detection of 6 additional GRB-SNe at both local and cosmological redshifts. This review summarizes the recent observations of SNe associated with GRBs 081007, 090618, 091127, 100316D, 101219B and 111211A, as well as the observations of SN 2008D, which was associated with a bright X-ray flash (XRF 080109) and may represent a link between “plain” SN and GRB-SNe. It is now clear that most – if not all – long-duration GRBs are produced by the core collapse of massive stars.

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Pre-supernova activity as a possible explanation of the peculiar properties of Type IIP supernova 2009kf

Monthly Notices of the Royal Astronomical Society ◽

10.1093/mnras/staa2527 ◽

2020 ◽

Vol 500 (2) ◽

pp. 1889-1894

Author(s):

Ryoma Ouchi ◽

Keiichi Maeda

Keyword(s):

Observational Data ◽

Explosion Energy ◽

Core Collapse ◽

Plateau Phase ◽

The Core ◽

V Band ◽

Constant Rate

ABSTRACT SN 2009kf is an exceptionally bright Type IIP supernova (SN IIP) discovered by the Pan-STARRS 1 survey. The V-band magnitude in the plateau phase is MV = −18.4 mag, which is much brighter than that for typical SNe IIP. We propose that its unusual properties can be naturally explained if we assume that there was a super-Eddington energy injection into the envelope in the last few years of the evolution before the SN explosion. Using a progenitor model with such a pre-SN energy injection, we can fit the observational data of SN 2009kf with a reasonable explosion energy of Eexp = 2.8 × 1051 erg and 56Ni mass of 0.25 M⊙. Specifically, we injected the energy into the envelope at a constant rate of 3.0 × 1039 erg s−1 in the last 3.0 yr of evolution before the core collapse. We propose that some unusually bright SNe IIP might result from pre-SN energy injection into the envelope.

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Radiation hydrodynamical simulations of eruptive mass loss from progenitors of Type Ibn/IIn supernovae

Astronomy and Astrophysics ◽

10.1051/0004-6361/201937226 ◽

2020 ◽

Vol 635 ◽

pp. A127 ◽

Cited By ~ 2

Author(s):

Naoto Kuriyama ◽

Toshikazu Shigeyama

Keyword(s):

Mass Loss ◽

Massive Star ◽

Massive Stars ◽

Circumstellar Matter ◽

Core Collapse ◽

The Core ◽

Actual Mechanism ◽

Nuclear Burning ◽

Hydrodynamical Simulations ◽

Extract Information

Context. Observations suggest that some massive stars experience violent and eruptive mass loss associated with significant brightening that cannot be explained by hydrostatic stellar models. This event seemingly forms dense circumstellar matter (CSM). The mechanism of eruptive mass loss has not been fully explained. We focus on the fact that the timescale of nuclear burning gets shorter than the dynamical timescale of the envelope a few years before core collapse for some massive stars. Aims. To reveal the properties of the eruptive mass loss, we investigate its relation to the energy injection at the bottom of the envelope supplied by nuclear burning taking place inside the core. In this study, we do not specify the actual mechanism for transporting energy from the site of nuclear burning to the bottom of the envelope. Instead, we parameterize the amount of injected energy and the injection time and try to extract information on these parameters from comparisons with observations. Methods. We carried out 1D radiation hydrodynamical simulations for progenitors of red, yellow, and blue supergiants, and Wolf–Rayet stars. We calculated the evolution of the progenitors with a public stellar evolution code. Results. We obtain the light curve associated with the eruption, the amount of ejected mass, and the CSM distribution at the time of core-collapse. Conclusions. The energy injection at the bottom of the envelope of a massive star within a period shorter than the dynamical timescale of the envelope could reproduce some observed optical outbursts prior to the core-collapse and form the CSM, which can power an interaction supernova classified as Type IIn.

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Nucleosynthesis of the Elements in Faint Supernovae and Hypernovae

Proceedings of the International Astronomical Union ◽

10.1017/s1743921310000128 ◽

2009 ◽

Vol 5 (S265) ◽

pp. 34-41

Author(s):

Ken'ichi Nomoto ◽

Takashi Moriya ◽

Nozomu Tominaga

Keyword(s):

Black Holes ◽

Neutron Stars ◽

Electron Capture ◽

Massive Stars ◽

Core Collapse ◽

Agb Stars ◽

Intermediate Mass ◽

Normal Core ◽

Intermediate Mass Black Holes

AbstractWe review the properties of supernovae (SNe) as a function of the progenitor's mass M. (1) Mup - 10 M⊙ stars are super-AGB stars and resultant electron capture SNe may be Faint supernovae like Type IIn SN 2008S. (2) 10 - 12 M⊙ stars undergo Fe-core collapse to form neutron stars (NSs) and Faint supernovae. (3) 12 M⊙ - MBN stars undergo Fe-core collapse to form NSs and normal core-collapse supernovae. (4) MBN - 90 M⊙ stars undergo Fe-core collapse to form Black Holes. Resultant supernovae are bifurcate into Hypernovae and Faint supernovae. The observed properties of SN 2008ha can be explained with this type of Faint supernovae. (5) 90 - 140 M⊙ stars produce Luminous SNe, like SNe 2007bi and 2006gy. (6) 140 - 300 M⊙ stars become pair-instability supernovae which could be Luminous supernovae (SNe 2007bi and 2006gy). (7) Very massive stars with M ≳ 300 M⊙ undergo core-collapse to form intermediate mass black holes. Some SNe could be more Luminous supernovae (like SN 2006gy).

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PTF11rka: an interacting supernova at the crossroads of stripped-envelope and H-poor superluminous stellar core collapses

Monthly Notices of the Royal Astronomical Society ◽

10.1093/mnras/staa2191 ◽

2020 ◽

Vol 497 (3) ◽

pp. 3542-3556

Author(s):

E Pian ◽

P A Mazzali ◽

T J Moriya ◽

A Rubin ◽

A Gal-Yam ◽

...

Keyword(s):

Kinetic Energy ◽

Light Curve ◽

Lower Energy ◽

Rest Frame ◽

Main Sequence ◽

Gamma Ray ◽

Core Collapse ◽

Curve Shape ◽

Maximum Brightness ◽

The Core

ABSTRACT The hydrogen-poor supernova (SN) PTF11rka (z = 0.0744), reported by the Palomar Transient Factory, was observed with various telescopes starting a few days after the estimated explosion time of 2011 December 5 UT and up to 432 rest-frame days thereafter. The rising part of the light curve was monitored only in the RPTF filter band, and maximum in this band was reached ∼30 rest-frame days after the estimated explosion time. The light curve and spectra of PTF11rka are consistent with the core-collapse explosion of a ∼10 M⊙ carbon–oxygen core evolved from a progenitor of main-sequence mass 25–40 M⊙, that liberated a kinetic energy Ek≈4 × 1051 erg, expelled ∼8 M⊙ of ejecta, and synthesized ∼0.5 M⊙ of 56Ni. The photospheric spectra of PTF11rka are characterized by narrow absorption lines that point to suppression of the highest ejecta velocities (≳ 15 000 km s−1). This would be expected if the ejecta impacted a dense, clumpy circumstellar medium. This in turn caused them to lose a fraction of their energy (∼5 × 1050 erg), less than 2 per cent of which was converted into radiation that sustained the light curve before maximum brightness. This is reminiscent of the superluminous SN 2007bi, the light-curve shape and spectra of which are very similar to those of PTF11rka, although the latter is a factor of 10 less luminous and evolves faster in time. PTF11rka is in fact more similar to gamma-ray burst SNe in luminosity, although it has a lower energy and a lower Ek/Mej ratio.

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