scholarly journals The γ-ray deposition histories of core-collapse supernovae

2020 ◽  
Vol 496 (4) ◽  
pp. 4517-4545 ◽  
Author(s):  
Amir Sharon ◽  
Doron Kushnir
Keyword(s):  
Negative Correlation ◽  
Radiation Transfer ◽  
Mass Range ◽  
Light Curves ◽  
Initial Mass ◽  
Core Collapse ◽  
Type Ia ◽  
Γ Ray ◽  
Integrated Luminosity

ABSTRACT The γ-ray deposition history in an expanding supernova (SN) ejecta has been mostly used to constrain models for Type Ia SN. Here we expand this methodology to core-collapse SNe, including stripped envelope (SE; Type Ib/Ic/IIb) and Type IIP SNe. We construct bolometric light curves using photometry from the literature and we use the Katz integral to extract the γ-ray deposition history. We recover the tight range of γ-ray escape times, $t_0\approx 30\!-\!45\, \textrm {d}$, for Type Ia SNe, and we find a new tight range $t_0\approx 80\!-\!140\, \textrm {d}$, for SE SNe. Type IIP SNe are clearly separated from other SNe types with $t_0\gtrsim 400\, \textrm {d}$, and there is a possible negative correlation between t0 and the synthesized 56Ni mass. We find that the typical masses of the synthesized 56Ni in SE SNe are larger than those in Type IIP SNe, in agreement with the results of Kushnir. This disfavours progenitors with the same initial mass range for these explosions. We recover the observed values of ET, the time-weighted integrated luminosity from cooling emission, for Type IIP, and we find hints of non-zero ET values in some SE SNe. We apply a simple γ-ray radiation transfer code to calculate the γ-ray deposition histories of models from the literature, and we show that the observed histories are a powerful tool for constraining models.

scholarly journals Synthetic observables for electron-capture supernovae and low-mass core collapse supernovae

2021 ◽  
Vol 503 (1) ◽  
pp. 797-814
Author(s):  
Alexandra Kozyreva ◽  
Petr Baklanov ◽  
Samuel Jones ◽  
Georg Stockinger ◽  
Hans-Thomas Janka
Keyword(s):  
Radiative Transfer ◽  
Light Curve ◽  
Electron Capture ◽  
Mass Range ◽  
Light Curves ◽  
Initial Mass ◽  
Core Collapse ◽  
Initial Composition ◽  
Solar Metallicity ◽  
Low Mass

ABSTRACT Stars in the mass range from 8 M⊙ to 10 M⊙ are expected to produce one of two types of supernovae (SNe), either electron-capture supernovae (ECSNe) or core-collapse supernovae (CCSNe), depending on their previous evolution. Either of the associated progenitors retain extended and massive hydrogen-rich envelopes and the observables of these SNe are, therefore, expected to be similar. In this study, we explore the differences in these two types of SNe. Specifically, we investigate three different progenitor models: a solar-metallicity ECSN progenitor with an initial mass of 8.8 M⊙, a zero-metallicity progenitor with 9.6 M⊙, and a solar-metallicity progenitor with 9 M⊙, carrying out radiative transfer simulations for these progenitors. We present the resulting light curves for these models. The models exhibit very low photospheric velocity variations of about 2000 km s−1; therefore, this may serve as a convenient indicator of low-mass SNe. The ECSN has very unique light curves in broad-bands, especially the U band, and does not resemble any currently observed SN. This ECSN progenitor being part of a binary will lose its envelope for which reason the light curve becomes short and undetectable. The SN from the 9.6 M⊙ progenitor exhibits also quite an unusual light curve, explained by the absence of metals in the initial composition. The artificially iron-polluted 9.6 M⊙ model demonstrates light curves closer to normal SNe IIP. The SN from the 9 M⊙ progenitor remains the best candidate for so-called low-luminosity SNe IIP like SN 1999br and SN 2005cs.

scholarly journals Type Ia supernovae from non-accreting progenitors

2020 ◽  
Vol 635 ◽  
pp. A72 ◽  
Author(s):  
J. Antoniadis ◽  
S. Chanlaridis ◽  
G. Gräfener ◽  
N. Langer
Keyword(s):  
Nuclear Energy ◽  
Mass Range ◽  
Type Ia Supernovae ◽  
Core Collapse ◽  
Star Forming ◽  
Helium Stars ◽  
Type Ia ◽  
Complete Disruption ◽  
Ia Supernovae ◽  
Thermonuclear Runaway

Type Ia supernovae (SNe Ia) are manifestations of stars that are deficient in hydrogen and helium, and disrupt in a thermonuclear runaway. While explosions of carbon-oxygen white dwarfs are thought to account for the majority of events, part of the observed diversity may be due to varied progenitor channels. We demonstrate that helium stars with masses between ∼1.8 and 2.5 M⊙ may evolve into highly degenerate cores with near-Chandrasekhar mass and helium-free envelopes that subsequently ignite carbon and oxygen explosively at densities of ∼(1.8−5.9) × 109 g cm−3. This occurs either due to core growth from shell burning (when the core has a hybrid CO/NeO composition), or following ignition of residual carbon triggered by exothermic electron captures on 24Mg (for a NeOMg-dominated composition). We argue that the resulting thermonuclear runaway is likely to prevent core collapse, leading to the complete disruption of the star. The available nuclear energy at the onset of explosive oxygen burning suffices to create ejecta with a kinetic energy of ∼1051 erg, as in typical SNe Ia. Conversely, if these runaways result in partial disruptions, the corresponding transients would resemble SN Iax events similar to SN 2002cx. If helium stars in this mass range indeed explode as SNe Ia, then the frequency of events would be comparable to the observed SN Ib/c rates, thereby sufficing to account for the majority of SNe Ia in star-forming galaxies.

scholarly journals Identifying Supernova Progenitors and Constraining the Explosion Channels

2011 ◽  
Vol 7 (S279) ◽  
pp. 110-117
Author(s):  
Schuyler D. Van Dyk
Keyword(s):  
Massive Star ◽  
Mass Range ◽  
Initial Mass ◽  
Current Status ◽  
Core Collapse ◽  
Evolutionary Models ◽  
Direct Identification ◽  
Star Evolution ◽  
Red Supergiants ◽  
Massive Star Evolution

AbstractConnecting the endpoints of massive star evolution with the various types of core-collapse supernovae (SNe) is ultimately the fundamental puzzle to be explored and solved. We can assemble clues indirectly, e.g., from information about the environments in which stars explode and establish constraints on the evolutionary phases of these stars. However, this is best accomplished through direct identification of the actual star that has exploded in pre-supernova imaging, preferably in more than one photometric band, where color and luminosity for the star can be precisely measured. We can then interpret the star's properties in light of expectations from the latest massive stellar evolutionary models, to attempt to assign an initial mass to the progenitor. So far, this has been done most successfully for SNe II-P, for which we now know that red supergiants in a relatively limited initial mass range are responsible. More recently, we have limited examples of the progenitors of SNe II-L, IIn, and IIb. The progenitors of SNe Ib and Ic, however, have been elusive so far; I will discuss the current status of our knowledge of this particular channel.

scholarly journals Core-Collapse Supernovae in the Early Universe: Radiation Hydrodynamics Simulations of Multicolor Light Curves

2016 ◽  
Vol 12 (S329) ◽  
pp. 451-451
Author(s):  
Alexey Tolstov ◽  
Ken’ichi Nomoto ◽  
Nozomu Tominaga ◽  
Miho Ishigaki ◽  
Sergei Blinnikov ◽  
...  
Keyword(s):  
First Generation ◽  
Supernova Explosion ◽  
Mass Range ◽  
Light Curves ◽  
Core Collapse ◽  
Solar Mass ◽  
Metal Free ◽  
Abundance Patterns ◽  
Detection And Identification ◽  
Hydrodynamic Code

AbstractThe properties of the first generation of stars and their supernova (SN) explosions remain unknown due to the lack of their actual observations. Pop III stars may have been very massive and predicted to be exploded as pair-instability SNe, but the observed metal-poor stars show the abundance patterns which are more consistent with yields of core-collapse SNe. We study the multicolor light curves for a metal-free core-collapse SN models (massive stars of 25-100 solar mass range) to determine the indicators for the detection and identification of first generation SNe. We use mixing-fallback supernova explosion models which explain the observed abundance patterns of metal poor stars. Numerical calculations of the multicolor light curves are performed using the multigroup radiation hydrodynamic code STELLA. The calculated light curves of metal-free SNe are compared with our calculations of non-zero metallicity models and observed SNe.

scholarly journals Progenitors of electron-capture supernovae

2011 ◽  
Vol 7 (S279) ◽  
pp. 341-342
Author(s):  
Samuel Jones ◽  
Raphael Hirschi ◽  
Falk Herwig ◽  
Bill Paxton ◽  
Francis X. Timmes ◽  
...  
Keyword(s):  
Electron Capture ◽  
Massive Star ◽  
Massive Stars ◽  
Large Fraction ◽  
Mass Range ◽  
Light Curves ◽  
Core Collapse ◽  
Type Ii ◽  
Agb Stars ◽  
Lower Edge

AbstractWe investigate the lowest mass stars that produce Type-II supernovae, motivated by recent results showing that a large fraction of type-II supernova progenitors for which there are direct detections display unexpectedly low luminosity (for a review see e.g. Smartt 2009). There are three potential evolutionary channels leading to this fate. Alongside the standard ‘massive star’ Fe-core collapse scenario we investigate the likelihood of electron capture supernovae (EC-SNe) from super-AGB (S-AGB) stars in their thermal pulse phase, from failed massive stars for which neon burning and other advanced burning stages fail to prevent the star from contracting to the critical densities required to initiate rapid electron-capture reactions and thus the star's collapse. We find it indeed possible that both of these relatively exotic evolutionary channels may be realised but it is currently unclear for what proportion of stars. Ultimately, the supernova light curves, explosion energies, remnant properties (see e.g. Knigge et al. 2011) and ejecta composition are the quantities desired to establish the role that these stars at the lower edge of the massive star mass range play.

scholarly journals Faint rapid red transients from neutron star–CO white dwarf mergers

2020 ◽  
Vol 493 (3) ◽  
pp. 3956-3965 ◽  
Author(s):  
Yossef Zenati ◽  
Alexey Bobrick ◽  
Hagai B Perets
Keyword(s):  
Adaptive Mesh Refinement ◽  
Radiation Transfer ◽  
Adaptive Mesh ◽  
Light Curves ◽  
Post Process ◽  
Type Ia ◽  
Particle Hydrodynamics ◽  
Smoothed Particle ◽  
Transient Events ◽  
Ia Supernovae

ABSTRACT Mergers of neutron stars (NS) and white dwarfs (WD) may give rise to observable explosive transient events. We use 3D hydrodynamical (smoothed particle hydrodynamics – SPH) simulations and 2D hydrodynamical–thermonuclear simulations (using the flash adaptive mesh refinement code) to model the disruption of CO-WDs by NSs, which produce faint transient events. We post-process the simulations using a large nuclear network and make use of the SuperNu radiation transfer code to predict the observational signatures and detailed properties of these transients. We calculate the light curves and spectra for five models of NS–CO-WD mergers. The small yields of 56Ni (few $\times 10^{-3}\, {\rm M_{\odot }}$) result in faint, rapidly evolving reddened transients (RRTs) with B(R) peak magnitudes of at most ∼−12 (−13) to ∼−13 (−15), much shorter and fainter than both regular and faint/peculiar Type Ia supernovae. These transients are likely to be accompanied by several months long, 1–2 mag dimmer red/infrared afterglows. We show that the spectra of RRTs share some similarities with rapidly evolving transients such as SN 2010X, although RRTs are significantly fainter, especially in the I/R bands, and show far stronger Si lines. We estimate that the upcoming Large Synoptic Survey Telescope could detect RRTs at a rate of up to ∼10–70 yr−1 through observations in the R/I bands. The qualitative agreement between the SPH and flash approaches supports the earlier hydrodynamical studies of these systems.

scholarly journals Spectrophotometric templates for core-collapse supernovae and their application in simulations of time-domain surveys

2019 ◽  
Vol 489 (4) ◽  
pp. 5802-5821 ◽  
Author(s):  
M Vincenzi ◽  
M Sullivan ◽  
R E Firth ◽  
C P Gutiérrez ◽  
C Frohmaier ◽  
...  
Keyword(s):  
Time Series ◽  
Time Domain ◽  
Light Curves ◽  
Host Galaxy ◽  
Core Collapse ◽  
Dust Extinction ◽  
Core Collapse Supernova ◽  
Near Ultraviolet ◽  
Luminosity Functions ◽  
Type Ia

ABSTRACT The design and analysis of time-domain sky surveys require the ability to simulate accurately realistic populations of core-collapse supernova (SN) events. We present a set of spectral time-series templates designed for this purpose, for both hydrogen-rich (Type II, IIn, and IIb) and stripped-envelope (Type Ib, Ic, and Ic-BL) core-collapse SNe. We use photometric and spectroscopic data for 67 core-collapse SNe from the literature, and for each generate a time-series spectral template. The techniques used to build the templates are fully data driven with no assumption of any parametric form or model for the light curves. The template-building code is open source, and can be applied to any transient for which well-sampled multiband photometry and multiple spectroscopic observations are available. We extend these spectral templates into the near-ultraviolet to λ ≃ 1600 Å using observer-frame ultraviolet photometry. We also provide a set of templates corrected for host galaxy dust extinction, and provide a set of luminosity functions that can be used with our spectral templates in simulations. We give an example of how these templates can be used by integrating them within the popular SN simulation package snana, and simulating core-collapse SNe in photometrically selected cosmological Type Ia SN samples, prone to contamination from core-collapse events.

scholarly journals The impact of asymmetric neutrino emissions on nucleosynthesis in core-collapse supernovae II – progenitor dependences

2021 ◽  
Vol 502 (2) ◽  
pp. 2319-2330
Author(s):  
Shin-ichiro Fujimoto ◽  
Hiroki Nagakura
Keyword(s):  
Mass Range ◽  
Mass Function ◽  
Abundance Ratio ◽  
Initial Mass Function ◽  
Core Collapse ◽  
Hydrodynamic Simulations ◽  
Type Ia ◽  
Solar Abundances ◽  
The Difference ◽  
The Impact

ABSTRACT We investigate the impact of asymmetric neutrino emissions on explosive nucleosynthesis in core-collapse supernovae (CCSNe) of progenitors with a mass range of 9.5–25 M⊙. We perform axisymmetric, hydrodynamic simulations of the CCSN explosion with a simplified neutrino transport, in which anticorrelated dipolar emissions of νe and ${\bar{\nu }}_{\rm e}$ are imposed. We then evaluate abundances and masses of the CCSN ejecta in a post-processing manner. We find that the asymmetric ν-emission leads to the abundant ejection of p- and n-rich matter in the high-νe and -${\bar{\nu }}_{\rm e}$ hemispheres, respectively. It substantially affects the abundances of the ejecta for elements heavier than Ni regardless of progenitors, although those elements lighter than Ca are less sensitive. Based on these results, we calculate the initial mass function-averaged abundances of the CCSN ejecta with taking into account the contribution from Type Ia SNe. For $m_{\rm asy} = 10/3{{\ \rm per\ cent}}$ and $10{{\ \rm per\ cent}}$, where masy denotes the asymmetric degree of the dipole components in the neutrino emissions, the averaged abundances for elements lighter than Y are comparable to those of the solar abundances, whereas those of elements heavier than Ge are overproduced in the case with $m_{\rm asy} \ge 30{{\ \rm per\ cent}}$. Our result also suggests that the effect of the asymmetric neutrino emissions is imprinted in the difference of abundance ratio of [Ni/Fe] and [Zn/Fe] between the high-νe and -${\bar{\nu }}_{\rm e}$ hemispheres, indicating that the future spectroscopic X-ray observations of a CCSN remnant will bring evidence of the asymmetric neutrino emissions if exist.

scholarly journals Gravitational Collapse versus Thermonuclear Explosion of Degenerate Stellar Cores

1994 ◽  
Vol 147 ◽  
pp. 186-213
Author(s):  
J. Isern ◽  
R. Canal
Keyword(s):  
Neutron Star ◽  
White Dwarfs ◽  
Light Curves ◽  
Type Ia Supernovae ◽  
Radioactive Elements ◽  
Border Line ◽  
Thermonuclear Explosion ◽  
Type Ia ◽  
Γ Rays ◽  
Ia Supernovae

AbstractIn this paper we review the behavior of growing stellar degenerate cores. It is shown that ONeMg white dwarfs and cold CO white dwarfs can collapse to form a neutron star. This collapse is completely silent since the total amount of radioactive elements that are expelled is very small and a burst of γ-rays is never produced. In the case of an explosion (always carbonoxygen cores), the outcome fits quite well the observed properties of Type Ia supernovae. Nevertheless, the light curves and the velocities measured at maximum are very homogeneous and the diversity introduced by igniting at different densities is not enough to account for the most extreme cases observed. It is also shown that a promising way out of this problem could be the He-induced detonation of white dwarfs with different masses. Finally, we outline that the location of the border line which separetes explosion from collapse strongly depends on the input physics adopted.

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