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1
Nomoto, Ken'ichi. « Core Collapse Supernova Models and Nucleosynthesis ». Proceedings of the International Astronomical Union 9, S296 (janvier 2013) : 27–36. http://dx.doi.org/10.1017/s1743921313009198.
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AbstractAfter the Big Bang, production of heavy elements in the early Universe takes place in the first stars and their supernova explosions. The nature of the first supernovae, however, has not been well understood. The signature of nucleosynthesis yields of the first supernovae can be seen in the elemental abundance patterns observed in extremely metal-poor stars. Interestingly, those abundance patterns show some peculiarities relative to the solar abundance pattern, which should provide important clues to understanding the nature of early generations of supernovae. We review the recent results of the nucleosynthesis yields of massive stars. We examine how those yields are affected by some hydrodynamical effects during the supernova explosions, namely, explosion energies from those of hypernovae to faint supernovae, mixing and fallback of processed materials, asphericity, etc. Those parameters in the supernova nucleosynthesis models are constrained from observational data of supernovae and metal-poor stars.
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Jones, Samuel, Raphael Hirschi, Falk Herwig, Bill Paxton, Francis X. Timmes et Ken'ichi Nomoto. « Progenitors of electron-capture supernovae ». Proceedings of the International Astronomical Union 7, S279 (avril 2011) : 341–42. http://dx.doi.org/10.1017/s1743921312013257.
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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.
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Nomoto, Ken'ichi, et Tomoharu Suzuki. « Supernova Yields for Chemical Evolution Modeling ». Proceedings of the International Astronomical Union 9, S298 (mai 2013) : 154–66. http://dx.doi.org/10.1017/s1743921313006327.
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AbstractWe review the recent results of the nucleosynthesis yields of massive stars. We examine how those yields are affected by some hydrodynamical effects during the supernova explosions, namely, explosion energies from those of hypernovae to faint supernovae, mixing and fallback of processed materials, asphericity, etc. Those parameters in the supernova nucleosynthesis models are constrained from observational data of supernovae and metal-poor stars. The elemental abundance patterns observed in extremely metal-poor stars show some peculiarities relative to the solar abundance pattern, which suggests the important contributions of hypernovae and faint supernovae in the early chemical enrichment of galaxies. These constraints on supernova nucleosynthesis are taken into account in the latest yield table for chemical evolution modeling.
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Maund, Justyn R., Paul A. Crowther, Hans-Thomas Janka et Norbert Langer. « Bridging the gap : from massive stars to supernovae ». Philosophical Transactions of the Royal Society A : Mathematical, Physical and Engineering Sciences 375, no 2105 (18 septembre 2017) : 20170025. http://dx.doi.org/10.1098/rsta.2017.0025.
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Almost since the beginning, massive stars and their resultant supernovae have played a crucial role in the Universe. These objects produce tremendous amounts of energy and new, heavy elements that enrich galaxies, encourage new stars to form and sculpt the shapes of galaxies that we see today. The end of millions of years of massive star evolution and the beginning of hundreds or thousands of years of supernova evolution are separated by a matter of a few seconds, in which some of the most extreme physics found in the Universe causes the explosive and terminal disruption of the star. Key questions remain unanswered in both the studies of how massive stars evolve and the behaviour of supernovae, and it appears the solutions may not lie on just one side of the explosion or the other or in just the domain of the stellar evolution or the supernova astrophysics communities. The need to view massive star evolution and supernovae as continuous phases in a single narrative motivated the Theo Murphy international scientific meeting ‘Bridging the gap: from massive stars to supernovae’ at Chicheley Hall, UK, in June 2016, with the specific purpose of simultaneously addressing the scientific connections between theoretical and observational studies of massive stars and their supernovae, through engaging astronomers from both communities. This article is part of the themed issue ‘Bridging the gap: from massive stars to supernovae’.
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Nomoto, K., T. Shigeyama et T. Tsujimoto. « Supernova Abundance Generation ». Symposium - International Astronomical Union 145 (1991) : 21–38. http://dx.doi.org/10.1017/s007418090022723x.
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Theoretical models of supernova explosions of various types are reviewed to obtain heavy element yields from supernovae. We focus on new models for SN 1987A, and Type Ia, Ib, and Ic supernovae. Maximum brightness and decline rate of their light curves suggest that 12–18 M⊙ stars produce larger amount of 56Ni than more massive stars. We discuss relative roles of various types of supernovae in the chemical evolution of galaxies.
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Waldman, Roni. « Around the Pair Instability Valley – Massive SN Progenitors ». Proceedings of the International Astronomical Union 4, S252 (avril 2008) : 329–32. http://dx.doi.org/10.1017/s1743921308023120.
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AbstractThe discovery of the extremely luminous supernova SN 2006gy, possibly interpreted as a pair instability supernova, renewed the interest in very massive stars. We explore the evolution of these objects, which end their life as pair instability supernovae or as core collapse supernovae with relatively massive iron cores, up to about 3 M⊙.
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Magg, Mattis, Anna T. P. Schauer, Ralf S. Klessen, Simon C. O. Glover, Robin G. Tress et Ondrej Jaura. « Metal Mixing in Minihalos : The Descendants of Pair-instability Supernovae ». Astrophysical Journal 929, no 2 (1 avril 2022) : 119. http://dx.doi.org/10.3847/1538-4357/ac5aac.
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Abstract The lack of observations of abundance patterns originating in pair-instability supernovae has been a long-standing problem in relation to the first stars. This class of supernovae is expected to have an abundance pattern with a strong odd–even effect, making it substantially different from present-day supernovae. In this study, we use a cosmological radiation hydrodynamics simulation to model such supernovae and the subsequent formation of the second generation of stars. We incorporate streaming velocities for the first time. There are 14 star-forming minihalos in our 1 cMpc h −1 box, leading to 14 supernovae occurring before redshift z = 19.5, where we start reducing the complexity of the simulation. Following the explosions, extremely metal-poor stars form in 10 halos via internal and external enrichment, which makes it the most common outcome. Only one halo does not recollapse during the simulations. This result is at variance with the current (lack of) observations of metal-poor stars with pair-instability supernova abundance patterns, suggesting that these very massive stars might be rare even in the early universe. The results from this simulation also give us insights into what drives different modes of recollapse and what determines the mixing behavior of metals after very energetic supernovae.
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Eldridge, John J. « Massive stars in their death throes ». Philosophical Transactions of the Royal Society A : Mathematical, Physical and Engineering Sciences 366, no 1884 (23 septembre 2008) : 4441–52. http://dx.doi.org/10.1098/rsta.2008.0160.
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The study of the stars that explode as supernovae used to be a forensic study, working backwards from the remnants of the star. This changed in 1987 when the first progenitor star was identified in pre-explosion images. Currently, there are eight detected progenitors with another 21 non-detections, for which only a limit on the pre-explosion luminosity can be placed. This new avenue of supernova research has led to many interesting conclusions, most importantly that the progenitors of the most common supernovae, type IIP, are red supergiants, as theory has long predicted. However, no progenitors have been detected thus far for the hydrogen-free type Ib/c supernovae, which, given the expected progenitors, is an unlikely result. Also, observations have begun to show evidence that luminous blue variables, which are among the most massive stars, may directly explode as supernovae. These results contradict the current stellar evolution theory. This suggests that we may need to update our understanding.
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Chevalier, R. A. « Supernovae and Stellar Mass Loss ». Highlights of Astronomy 7 (1986) : 599–609. http://dx.doi.org/10.1017/s1539299600007000.
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AbstractType I supernovae can be modeled as the carbon deflagration of white dwarfs and Type II supernovae as the explosions of massive stars with hydrogen envelopes. The massive stars at the ends of their lives are expected to be red supergiants, which are observed to have slow, dense winds. The interaction of the supernova kinetic energy and radiation with the circumstellar gas gives rise to observational phenomena at a range of wavelengths. Additional phenomena, such as a scattered light echo, are predicted. While the light from a Type II supernova near maximum light is probably from energy deposited in the initial explosion, there is now good evidence that the radioactive decay of 56Co powers the emission at late times. It was been noted that the explosions of massive stars without hydrogen envelopes would be quite unlike normal Type II supernovae. There is now good evidence for such explosions – SN1985f and the class of peculiar Type I supernovae. It is suggested that these supernovae be called Type III with the spectroscopic definition of a) no H lines and b) broad [01] lines at late times. That not all very massive star explosions are of this type is indicated by SN1961v, which was probably a very massive explosion, but in which hydrogen was present.
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Neuhäuser, R., F. Gießler et V. V. Hambaryan. « A nearby recent supernova that ejected the runaway star ζ Oph, the pulsar PSR B1706−16, and 60Fe found on Earth ». Monthly Notices of the Royal Astronomical Society 498, no 1 (23 septembre 2019) : 899–917. http://dx.doi.org/10.1093/mnras/stz2629.
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ABSTRACT The detection of ∼1.5–3.2 Myr old 60Fe on Earth indicates recent nearby core-collapse supernovae. For supernovae in multiple stars, the primary stars may become neutron stars, while former companions may become unbound and become runaway stars. We wrote software for tracing back the space motion of runaway and neutron stars to young associations of massive stars. We apply it here to the nearby young Scorpius–Centaurus–Lupus groups, all known runaway stars possibly coming from there, and all 400 neutron stars with known transverse velocity. We find kinematic evidence that the runaway ζ Oph and the radio pulsar PSR B1706−16 were released by a supernova in a binary 1.78 ± 0.21 Myr ago at 107 ± 4 pc distance (for pulsar radial velocity 260 ± 43 km s−1); association age and flight time determine the progenitor mass (16–18 M⊙), which can constrain supernova nucleosynthesis yields and 60Fe uptake on Earth. In addition, we notice that the only high-mass X-ray binary in Scorpius–Centaurus–Lupus (1H11255−567 with μ1 and μ2 Cru) may include a neutron star formed in another SN, up to ∼1.8 Myr ago at 89−112 pc, i.e. also yielding 60Fe detectable on Earth. Our scenario links 60Fe found on Earth to one or two individual supernovae in multiple stars.
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Nomoto, Ken'ichi, Masaomi Tanaka, Yasuomi Kamiya, Nozomu Tominaga et Keiichi Maeda. « First Stars – Type Ib Supernovae Connection ». Proceedings of the International Astronomical Union 4, S255 (juin 2008) : 182–88. http://dx.doi.org/10.1017/s1743921308024794.
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AbstractThe very peculiar abundance patterns observed in extremely metal-poor (EMP) stars can not be explained by conventional normal supernova nucleosynthesis but can be well-reproduced by nucleosynthesis in hyper-energetic and hyper-aspherical explosions, i.e., Hypernovae (HNe). Previously, such HNe have been observed only as Type Ic supernovae. Here, we examine the properties of recent Type Ib supernovae (SNe Ib). In particular, SN Ib 2008D associated with the luminous X-ray transient 080109 is found to be a more energetic explosion than normal core-collapse supernovae. We estimate that the progenitor's main sequence mass is MMS = 20 − 25M⊙ with an explosion of kinetic energy of EK ~ 6.0 × 1051 erg. These properties are intermediate between those of normal SNe and hypernovae associated with gamma-ray bursts. Therefore, such energetic SNe Ib could also make an important contribution to the chemical enrichment in the early Universe.
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Nomoto, Ken’ichi. « First stars, hypernovae, and superluminous supernovae ». International Journal of Modern Physics D 25, no 10 (25 août 2016) : 1630025. http://dx.doi.org/10.1142/s0218271816300251.
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After the big bang, production of heavy elements in the early universe takes place starting from the formation of the first (Pop III) stars, their evolution, and explosion. The Pop III supernova (SN) explosions have strong dynamical, thermal, and chemical feedback on the formation of subsequent stars and evolution of galaxies. However, the nature of Pop III stars/supernovae (SNe) have not been well-understood. The signature of nucleosynthesis yields of the first SN can be seen in the elemental abundance patterns observed in extremely metal-poor (EMP) stars. We show that the abundance patterns of EMP stars, e.g. the excess of C, Co, Zn relative to Fe, are in better agreement with the yields of hyper-energetic explosions (Hypernovae, (HNe)) rather than normal supernovae. We note the large variation of the abundance patterns of EMP stars propose that such a variation is related to the diversity of the GRB-SNe and posssibly superluminous supernovae (SLSNe). For example, the carbon-enhanced metal-poor (CEMP) stars may be related to the faint SNe (or dark HNe), which could be the explosions induced by relativistic jets. Finally, we examine the various mechanisms of SLSNe.
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Nomoto, Ken'ichi, Shinya Wanajo, Yasuomi Kamiya, Nozomu Tominaga et Hideyuki Umeda. « Chemical Yields from Supernovae and Hypernovae ». Proceedings of the International Astronomical Union 4, S254 (juin 2008) : 355–68. http://dx.doi.org/10.1017/s1743921308027816.
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AbstractWe review the final stages of stellar evolution, supernova properties, and chemical yields as a function of the progenitor's mass. (1) 8 - 10 M⊙ stars are super-AGB stars when the O+Ne+Mg core collapses due to electron capture. These AGB-supernovae may constitute an SN 2008S-like sub-class of Type IIn supernovae. These stars produce little α-elements and Fe-peak elements, but are important sources of Zn and light p-nuclei. (2) 10 - 90 M⊙ stars undergo Fe-core collapse. Nucleosynthesis in aspherical explosions is important, as it can well reproduce the abundance patterns observed in extremely metal-poor stars. (3) 90 - 140 M⊙ stars undergo pulsational nuclear instabilities at various nuclear burning stages, including O and Si-burning. (4) Very massive stars with M ≳ 140 M⊙ either become pair-instability SNe, or undergo core-collapse to form intermediate mass black holes if the mass loss is small enough.
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Leibundgut, Bruno. « Light Curves of Supernovae ». International Astronomical Union Colloquium 145 (1996) : 11–18. http://dx.doi.org/10.1017/s0252921100007867.
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Although emerging from a range of progenitor stars and the product of different explosion mechanisms the light curves of the various supernova types are shaped mainly by radioactive power. Core-collapse supernovae have in addition early peaks from shock breakout with a subsequent cooling phase and massive extended stars a recombination (plateau) phase. Variations occur mostly due to differences of the progenitor stars. While there appears to be a fair understanding of the light curves of SNell, new wrinkles are emerging for SNela. The photometry of SNe lb and SNe Ic remains unsatisfactory.
15
Chen, Ke-Jung. « Supernovae at the Extremes ». Proceedings of the International Astronomical Union 11, A29B (août 2015) : 218–19. http://dx.doi.org/10.1017/s1743921316004981.
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AbstractDuring a supernova explosion, fluid instabilities are generated because the star is in a hydrodynamically unstable situation, which is like the effects of stirring a fire or blowing air into a hot grill. The resulting mixing of the supernova ejecta may be observable. Here, we briefly discuss the multidimensional simulations of supernovae from very massive stars.
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Velusamy, T. « Guest Stars : Historical Supernovae and Remnants ». International Astronomical Union Colloquium 91 (1987) : 265–70. http://dx.doi.org/10.1017/s0252921100106153.
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Supernova explosions occur in massive stars in their final stages of stellar evolution. The explosion leaves behind a collapsed object, usually a neutron star observable as a pulsar, and an expanding outer envelope of the star observable as a supernova remnant (SNR). Because of the large amount of energy in the range of 1050 −1052 ergs released in the explosion, the energy radiated by the exploded star is equivalent to that of millions of normal stars. Thus a "new star" seems to appear and is easily visible to the naked eye for several months. Astronomers have estimated that in our galaxy such supernova explosions occur once about every 50 years. In ancient times, the occurrence of supernova might have been noticed as appearance of a bright new star which faded away into obscruity after a few months. Thus the ‘guest stars’ in the ancient records are indeed possible occurrences of supernova explosions in the galaxy. The guest star of 1054 A.D., well recorded by Chinese and Japanese astronomers is the best known historic supernova (Brecher et al. 1983; and references therein); today its remnants the Crab Nebula and the pulsar are observable over the entire electromagnetic spectrum from radio to γ-rays. Of the 150 SNRs known in our galaxy, only about 10 have been identified with guest stars of historical supernovae.
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Langer, Norbert, et Alexander Heger. « Evolution and explosion of Wolf-Rayet stars ». Symposium - International Astronomical Union 193 (1999) : 187–95. http://dx.doi.org/10.1017/s0074180900205299.
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We investigate the pre-supernova evolution of Wolf-Rayet stars. We discuss whether the separation of hydrogen-free, core collapse supernovae into Type Ic and Type Ib supernovae is related to the occurrence of ‘Case BB mass transfer’ in massive close binaries, especially since the new, smaller WR mass loss rates do not favor helium-poor progenitor models from massive single stars. We also discuss the influence of rotation on the formation, evolution and explosion of WR stars using new models for rotating massive stars that have been computed from zero age to core collapse. We compute the spin-down of (non-magnetic) WR stars due to their strong mass loss, and compare pulsar spin rates with our predictions. Finally, we discuss implications of our results for the rotation rate of Type Ib/c supernova progenitors in general, and for SN 1998bw and the ‘collapsar’ model for γ-ray bursts in particular.
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Nomoto, Ken'ichi, Takashi Moriya et Nozomu Tominaga. « Nucleosynthesis of the Elements in Faint Supernovae and Hypernovae ». Proceedings of the International Astronomical Union 5, S265 (août 2009) : 34–41. http://dx.doi.org/10.1017/s1743921310000128.
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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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Woosley, S. E., et Thomas A. Weaver. « The Physics of Supernovae ». International Astronomical Union Colloquium 89 (1986) : 90–120. http://dx.doi.org/10.1017/s0252921100086048.
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AbstractPresupernova models of massive stars are presented and their explosion by “delayed neutrino transport” examined. A new form of long duration Type II supernova model is also explored based upon repeated encounter with the electron-positron pair instability in stars heavier than about 60 M⊙. Carbon deflagration in white dwarfs is discussed as the probable explanation of Type I supernovae and special attention is paid to the physical processes whereby a nuclear flame propagates through degenerate carbon.
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Kokaia, Giorgi, et Melvyn B. Davies. « Stellar encounters with giant molecular clouds ». Monthly Notices of the Royal Astronomical Society 489, no 4 (10 avril 2019) : 5165–80. http://dx.doi.org/10.1093/mnras/stz813.
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ABSTRACTGiant molecular clouds (GMCs) are believed to affect the biospheres of planets as their host star passes through them. We simulate the trajectories of stars and GMCs in the Galaxy and determine how often stars pass through GMCs. We find a strong decreasing dependence with Galactocentric radius, and with the velocity perpendicular to the Galactic plane, V$\mathrm{ z}$. The XY-component of the kinematic heating of stars was shown to not affect the GMC hit rate, unlike the Z-dependence (V$\mathrm{ z}$) implies that stars hit fewer GMCs as they age. GMCs are locations of star formation, therefore we also determine how often stars pass near supernovae. For the supernovae the decrease with V$\mathrm{ z}$ is steeper as how fast the star passes through the GMC determines the probability of a supernova encounter. We then integrate a set of Sun-like trajectories to see the implications for the Sun. We find that the Sun hits 1.6 ± 1.3 GMCs per Gyr which results in 1.5 ± 1.1 or (with correction for clustering) 0.8 ± 0.6 supernova closer than 10 pc per Gyr. The different the supernova frequencies are from whether one considers multiple supernovae per GMC crossing (few Myr) as separate events. We then discuss the effect of the GMC hits on the Oort cloud, and the Earth’s climate due to accretion, we also discuss the records of distant supernova. Finally, we determine Galactic Habitable Zone using our model. For the thin disc, we find it to lie between 5.8 and 8.7 kpc and for the thick disc to lie between 4.5 and 7.7 kpc.
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Smith, Nathan. « Episodic Mass Loss and Pre-SN Circumstellar Envelopes ». Proceedings of the International Astronomical Union 3, S250 (décembre 2007) : 193–200. http://dx.doi.org/10.1017/s1743921308020498.
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AbstractI discuss observational clues concerning episodic mass-loss properties of massive stars in the time before the final supernova explosion. In particular, I will focus on the mounting evidence that LBVs and related stars are candidates for supernova progenitors, even though current paradigms place them at the end of core-H burning. Namely, conditions in the immediate circumstellar environment within a few 102 AU of Type IIn supernovae require very high progenitor mass-loss rates. Those rates are so high that the only known stars that come close are LBVs during rare giant eruptions. I will highlight evidence from observations of some recent extraordinary supernovae suggesting that explosive or episodic mass loss (a.k.a. LBV eruptions like the 19th century eruption of Eta Car) occur in the 5-10 years immediately preceding the SN. Finally, I will discuss some implications for stellar evolution from these SNe, the most important of which is the observational fact that the most massive stars can indeed make it to the ends of their lives with substantial H envelopes intact, even at Solar metallicity.
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Fraser, Morgan. « Supernovae and transients with circumstellar interaction ». Royal Society Open Science 7, no 7 (juillet 2020) : 200467. http://dx.doi.org/10.1098/rsos.200467.
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It is 30 years since the characteristic signatures of interaction with circumstellar material (CSM) were first observed in a core-collapse supernova. Since then, CSM interaction has been observed and inferred across a range of transients, from the low-energy explosions of low-mass stars as likely electron-capture supernovae, through to the brightest superluminous supernovae. In this review, I present a brief overview of some of the interacting supernovae and transients that have been observed to date, and attempt to classify and group them together in a phenomenological framework.
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Nomoto, K. « Explosions of Helium Stars and Type IB/IC/IIB Supernovae ». Symposium - International Astronomical Union 143 (1991) : 515–28. http://dx.doi.org/10.1017/s0074180900045691.
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Theoretical models of supernova explosions of helium stars with various masses are reviewed to examine possible connections between Wolf-Rayet stars and Type Ib/Ic/IIb supernovae. Nucleosynthesis, Rayleigh-Taylor instabilities, and light curves are compared with observations. Maximum brightness and the fast decline of the light curves of typical SNe Ib/Ic can be well accounted for by the helium star models if the helium star mass is as low as 3-5 M⊙. These low mass helium stars can form from stars of 12-18 M⊙ after Roche-lobe overflow in close binary systems. Probably progenitors of typical SNe Ib/Ic are not classified as Wolf-Rayet stars.
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Moriya, Takashi J. « Light-curve and spectral properties of ultra-stripped core-collapse supernovae ». Proceedings of the International Astronomical Union 12, S329 (novembre 2016) : 426. http://dx.doi.org/10.1017/s1743921317000187.
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AbstractWe discuss light-curve and spectral properties of ultra-stripped core-collapse supernovae. Ultra-stripped supernovae are supernovae with ejecta masses of only ~0.1M⊙ whose progenitors lose their envelopes due to binary interactions with their compact companion stars. We follow the evolution of an ultra-stripped supernova progenitor until core collapse and perform explosive nucleosynthesis calculations. We then synthesize light curves and spectra of ultra-stripped supernovae based on the nucleosynthesis results. We show that ultra-stripped supernovae synthesize ~0.01M⊙ of the radioactive 56Ni, and their typical peak luminosity is around 1042 erg s−1 or −16 mag. Their typical rise time is 5 − 10 days. By comparing synthesized and observed spectra, we find that SN 2005ek and some of so-called calcium-rich gap transients like PTF10iuv may be related to ultra-stripped supernovae.
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Raddi, R., M. A. Hollands, D. Koester, J. J. Hermes, B. T. Gänsicke, U. Heber, K. J. Shen et al. « Partly burnt runaway stellar remnants from peculiar thermonuclear supernovae ». Monthly Notices of the Royal Astronomical Society 489, no 2 (21 juin 2019) : 1489–508. http://dx.doi.org/10.1093/mnras/stz1618.
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Abstract We report the discovery of three stars that, along with the prototype LP 40−365, form a distinct class of chemically peculiar runaway stars that are the survivors of thermonuclear explosions. Spectroscopy of the four confirmed LP 40−365 stars finds ONe-dominated atmospheres enriched with remarkably similar amounts of nuclear ashes of partial O- and Si-burning. Kinematic evidence is consistent with ejection from a binary supernova progenitor; at least two stars have rest-frame velocities indicating they are unbound to the Galaxy. With masses and radii ranging between 0.20 and 0.28 M$\odot$ and between 0.16 and 0.60 R$\odot$, respectively, we speculate these inflated white dwarfs are the partly burnt remnants of either peculiar Type Iax or electron-capture supernovae. Adopting supernova rates from the literature, we estimate that ∼20 LP 40−365 stars brighter than 19 mag should be detectable within 2 kpc from the Sun at the end of the Gaia mission. We suggest that as they cool, these stars will evolve in their spectroscopic appearance, and eventually become peculiar O-rich white dwarfs. Finally, we stress that the discovery of new LP 40−365 stars will be useful to further constrain their evolution, supplying key boundary conditions to the modelling of explosion mechanisms, supernova rates, and nucleosynthetic yields of peculiar thermonuclear explosions.
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LUGONES, GERMÁN, et JORGE E. HORVATH. « SUPERNOVAE, PROTONEUTRON STARS AND RELATED HIGH ENERGY PHENOMENA ». International Journal of Modern Physics D 13, no 07 (août 2004) : 1287–92. http://dx.doi.org/10.1142/s0218271804005432.
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We present a brief review of the present status of the standard model of core collapse supernovae and neutron star formation outlining the basic concepts and paying attention to the possibility of a transition to quark matter. We evaluate the consequences of this transition on the whole explosion mechanism, analyze the possible generation of beamed gamma ray bursts, and discuss the nature of the compact star born as a result of the supernova explosion.
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Wang, Zhenru. « Historical Supernovae and Supernova Remnants ». International Astronomical Union Colloquium 145 (1996) : 323–31. http://dx.doi.org/10.1017/s0252921100008174.
Texte intégralRésumé :
The oldest historical supernova (SN), recorded by ancient Chinese in 14th Century B.C. on pieces of tortoise shells or bones, is identified with the aid of modern space γ-ray observations. Hard X-rays with energy up to 20 keV were observed from IC 443 by the X-ray satellite Ginga. We infer from these observations the age of IC 443 is ∼ 1000 — 1400 yrs. The result supports the hypothesis that IC 443 is the remnant of the historical SN 837 that occurred during the Tang Dynasty. The association between the supernova remnant (SNR) CTB 80 and SN 1408 has been hotly debated for about ten years and is briefly reviewed and discussed here. A new picture is presented to explain this association. High energy emission from historical SNRs can persist in a multiphase interstellar medium (ISM). As a result, the study of the relationship between SNRs and ancient guest stars has gained new vitality.
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Nomoto, K., K. Iwamoto, T. Suzuki, O. R. Pols, H. Yamaoka, M. Hashimoto, P. Höflich et E. P. J. Van Den Heuvel. « The Origin of Type Ib-Ic-IIb-IIL Supernovae and Binary Star Evolution ». Symposium - International Astronomical Union 165 (1996) : 119–34. http://dx.doi.org/10.1017/s0074180900055613.
Texte intégralRésumé :
Supernovae are classified as type I and type II and further subdivided into Ia, Ib, Ic, II-P, II-L, and IIb. The origin of this observational diversity has not been well understood. The recent nearby supernovae SN 1993J and SN 1994I have provided particularly useful material to clarify the supernova — progenitor connection. For a progenitor of type IIb supernova 1993J, we propose that merging of two stars in a close binary is responsible for the formation of a thin H-rich envelope. As a progenitor of type Ic supernova 1994I, we propose a bare C+O star that has lost both its H and He envelope after a common-envelope phase. By generalizing these scenarios, we show that common-envelope evolution in massive close binary stars leads to various degrees of stripping off of the envelope of a massive star. This naturally leads to an explanation of the origin of type II-L, IIn, IIb, Ib, and Ic in a unified manner. The binary hypothesis to explain the diversity of supernovae can be substantiated with new information on SN IIb 1993J and SN Ic 1994I. Model light curves are compared with observations. Since extensive mass loss is essential for the binary scenario, circumstellar interactions are examined for comparison with X-ray observations.
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Kotak, Rubina. « Core-Collapse Supernovae as Dust Producers ». Proceedings of the International Astronomical Union 3, S250 (décembre 2007) : 437–42. http://dx.doi.org/10.1017/s1743921308020802.
Texte intégralRésumé :
AbstractAlthough it has long been hypothesised that core-collapse supernovae may produce large quantities of dust, interest in this problem has recently been rekindled given the enormous dust masses inferred at very high redshifts (z ≳ 6), when conventional low-mass dust-producing stars would fail to contribute significantly to the universal dust budget. Emission due to warm dust peaks at mid-IR wavelengths. However, with the notable exception of SN 1987A, supernova studies in the mid-IR have been virtually non-existent until the advent of the Spitzer Space Telescope. On behalf of the Mid-Infrared Supernova Consortium, I briefly discuss recent exciting results from mid-IR studies of core-collapse supernovae using Spitzer and attempt to put the role of supernovae as major dust producers into perspective.
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Nomoto, K., K. Maeda, H. Umeda et N. Tominaga. « Nucleosynthesis in Population III Supernovae ». Highlights of Astronomy 13 (2005) : 560–65. http://dx.doi.org/10.1017/s1539299600016580.
Texte intégralRésumé :
AbstractStars more massive than ~ 20–25 M⊙ form a black hole at the end of their evolution. Stars with non-rotating black holes are likely to collapse ”quietly” ejecting a small amount of heavy elements (Faint supernovae). In contrast, stars with rotating black holes are likely to give rise to very energetic supernovae (Hypernovae). Nucleosynthesis in Hypernovae is characterized by larger abundance ratios (Zn,Co,V,Ti)/Fe and smaller (Mn,Cr)/Fe than normal supernovae, which can explain the observed trend of these ratios in extremely metal-poor stars. Nucleosynthesis in Faint supernovae is characterized by a large amount of fall-back. We show that the abundance pattern of the recently discovered most Fe-poor star, HE0107-5240, and other extremely metal-poor carbon-rich stars are in good accord with those of black-hole-forming supernovae, but not pair-instability supernovae. This suggests that black-hole-forming supernovae made important contributions to the early Galactic (and cosmic) chemical evolution as the First (Pop III) Supernovae.
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Nomoto, Ken'ichi. « Final Fates of Massive Stars ». Proceedings of the International Astronomical Union 7, S279 (avril 2011) : 1–8. http://dx.doi.org/10.1017/s1743921312012604.
Texte intégralRésumé :
AbstractMassive stars are thought to play important roles in the early evolution of the Universe. In this paper, we first classify the final fates of massive stars into 7 cases according to their mass ranges. These variations of the final fate may correspond to the observed large diversities of supernova properties, such as extremely faint and extremely luminous (superluminous) supernovae, and the extremely energetic hypernovae. We then focus on the properties of the peculiar superluminous Type Ic supernova 1999as. We examine radioactive decay models, magnetar models, and circumstellar interaction models for the light curve of SN 1999as. We find that these models are not quite successful, and thus it is crucially important to improve these models to clarify the final fates of massive stars.
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Nomoto, K., K. Maeda, H. Umeda, N. Tominaga, T. Ohkubo, J. Deng et P. A. Mazzali. « Nucleosynthesis in Black-Hole-Forming Supernovae ». International Astronomical Union Colloquium 192 (2005) : 287–96. http://dx.doi.org/10.1017/s0252921100009313.
Texte intégralRésumé :
SummaryStars more massive than ~ 20 − 25 M⊙ form a black hole at the end of their evolution. Stars with non-rotating black holes are likely to collapse “quietly” ejecting a small amount of heavy elements (faint supernovae). In contrast, stars with rotating black holes are likely to give rise to very energetic supernovae (hypernovae). We present distinct nucleosynthesis features of these two types of “black-hole-forming” supernovae. Nucleosynthesis in hypernovae is characterized by larger abundance ratios (Zn, Co, V, Ti)/Fe and smaller (Mn, Cr)/Fe than normal supernovae, which can explain the observed trend of these ratios in extremely metal-poor stars. Nucleosynthesis in faint supernovae is characterized by a large amount of fall-back. We show that the abundance pattern of the recently discovered most Fe-poor star, HE0107-5240, and other extremely metal-poor carbon-rich stars are in good accord with those of black-hole-forming supernovae, but not pair-instability supernovae. This suggests that black-hole-forming supernovae made important contributions to the early Galactic (and cosmic) chemical evolution. Finally we discuss the nature of first (Pop III) Stars.
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Wheeler, J. Craig. « Luminous Content of Galaxies : Inferences from Supernovae ». Symposium - International Astronomical Union 116 (1986) : 467–76. http://dx.doi.org/10.1017/s0074180900149423.
Texte intégralRésumé :
Some luminous stars undoubtedly explode as supernovae, but it is not yet certain that fate awaits them all. The connection between luminous stars and supernovae is reviewed in terms of the statistical rates of supernovae and pulsars, the constraints of nucleosynthesis, and the various classifications of supernovae by their spectra and light curves, including a newly confirmed class of peculiar Type I supernovae.
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Woosley, S. E., T. A. Weaver et R. G. Eastman. « Progenitors and Hydrodynamics of Type II and lb Supernovae ». International Astronomical Union Colloquium 145 (1996) : 137–47. http://dx.doi.org/10.1017/s0252921100008009.
Texte intégralRésumé :
We review critical physics affecting the observational characteristics of those supernovae that occur in massive stars. Particular emphasis is given to 1) how mass loss, either to a binary companion or by a radiatively driven wind, affects the type and light curve of the supernova, and 2) the interaction of the outgoing supernova shock with regions of increasing pr3 in the stellar mantle. One conclusion is that Type II-L supernovae may occur in mass exchanging binaries very similar to the one that produced SN 1993J, but with slightly larger initial separations and residual hydrogen envelopes (∼1 Mʘ and radius ∼ several AU). The shock interaction, on the other hand, has important implications for the formation of black holes in explosions that are, near peak light, observationally indistinguishable from ordinary Type II-p and lb supernovae.
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Dwarkadas, Vikram V. « Massive star mass-loss revealed by X-ray observations of young supernovae ». Proceedings of the International Astronomical Union 14, S346 (août 2018) : 83–87. http://dx.doi.org/10.1017/s1743921318008438.
Texte intégralRésumé :
AbstractMassive stars lose a considerable amount of mass during their lifetime. When the star explodes as a supernova (SN), the resulting shock wave expands in the medium created by the stellar mass-loss. Thermal X-ray emission from the SN depends on the square of the density of the ambient medium, which in turn depends on the mass-loss rate (and velocity) of the progenitor wind. The emission can therefore be used to probe the stellar mass-loss in the decades or centuries before the star’s death.We have aggregated together data available in the literature, or analysed by us, to compute the X-ray lightcurves of almost all young supernovae detectable in X-rays. We use this database to explore the mass-loss rates of massive stars that collapse to form supernovae. Mass-loss rates are lowest for the common Type IIP supernovae, but increase by several orders of magnitude for the highest luminosity X-ray SNe.
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Howell, Andrew. « Determining the progenitors of supernovae with early robotic observations ». Proceedings of the International Astronomical Union 11, A29B (août 2015) : 222. http://dx.doi.org/10.1017/s1743921316005007.
Texte intégralRésumé :
AbstractWe present results from the LCOGT Supernova Key Project, a three year program to obtain lightcurves and spectra of 600 supernovae. The Las Cumbres Observatory Global Telescope Network is a network of eleven robotic 1m and 2m telescopes located at 5 sites around the world. With this facility long term monitoring of transient phenomena is possible, as are nearly instantaneous observations. We report on both core-collapse and thermonuclear supernovae observed within days of explosion, allowing insight into their progenitor stars.
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Zinner, Ernst. « Stardust in the Laboratory ». Publications of the Astronomical Society of Australia 25, no 1 (2008) : 7–17. http://dx.doi.org/10.1071/as07039.
Texte intégralRésumé :
AbstractPrimitive meteorites and interplanetary dust particles contain small grains that originated in stellar outflows and supernova explosions. These μm- and sub-μm-sized presolar grains can be isolated and studied for their isotopic compositions in the laboratory. They are recognised as stardust by their isotopic compositions, which are completely different from those of the Solar System. They provide new information on stellar evolution, nucleosynthesis, mixing processes in asymptotic giant branch (AGB) stars and supernovae, and Galactic chemical evolution. Red giants, AGB stars, Type II supernovae and possibly novae have been identified as stellar sources of the grains. Of the eight nuclear processes proposed by Burbidge et al. (1957), signatures of all except the r-process can be found in presolar dust grains.
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Kos, Janez, Joss Bland-Hawthorn, Sven Buder, Thomas Nordlander, Lorenzo Spina, Kevin L. Beeson, Karin Lind et al. « The GALAH survey : Chemical homogeneity of the Orion complex ». Monthly Notices of the Royal Astronomical Society 506, no 3 (28 juin 2021) : 4232–50. http://dx.doi.org/10.1093/mnras/stab1767.
Texte intégralRésumé :
ABSTRACT Due to its proximity, the Orion star forming region is often used as a proxy to study processes related to star formation and to observe young stars in the environment they were born in. With the release of Gaia DR2, the distance measurements to the Orion complex are now good enough that the 3D structure of the complex can be explored. Here we test the hypothesis that, due to non-trivial structure and dynamics, and age spread in the Orion complex, the chemical enrichment of youngest stars by early core-collapse supernovae can be observed. We obtained spectra of 794 stars of the Orion complex with the HERMES spectrograph at the Anglo Australian telescope as a part of the GALAH and GALAH-related surveys. We use the spectra of ∼300 stars to derive precise atmospheric parameters and chemical abundances of 25 elements for 15 stellar clusters in the Orion complex. We demonstrate that the Orion complex is chemically homogeneous and that there was no self-pollution of young clusters by core-collapse supernovae from older clusters; with a precision of 0.02 dex in relative alpha-elements abundance and 0.06 dex in oxygen abundance we would have been able to detect pollution from a single supernova, given a fortunate location of the SN and favourable conditions for ISM mixing. We estimate that the supernova rate in the Orion complex was very low, possibly producing no supernova by the time the youngest stars of the observed population formed (from around 21 to 8 Myr ago).
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SUMIYOSHI, KOHSUKE. « EQUATION OF STATE OF DENSE MATTER FOR CORE-COLLAPSE SUPERNOVAE AND NEUTRINO BURSTS ». Modern Physics Letters A 23, no 27n30 (30 septembre 2008) : 2451–54. http://dx.doi.org/10.1142/s0217732308029563.
Texte intégralRésumé :
We report the recent developments on the tables of equation of state for dense matter and their influence on core-collapse supernovae and associated neutrino emissions. We study the gravitational collapse of massive stars by the numerical simulations with the tables of equation of state recently developed in relativistic many body frameworks. I discuss whether the equation of state of dense matter can be probed by the properties of neutrino signals from black hole forming supernovae, being different from ordinary neutrino bursts from supernova explosions.
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Leibundgut, Bruno. « Type Ib/c Supernovae and their Relation to Binary Stars ». Symposium - International Astronomical Union 165 (1996) : 107–18. http://dx.doi.org/10.1017/s0074180900055601.
Texte intégralRésumé :
The present understanding of type Ib/c supernovae and their connection to interacting binaries is reviewed. The problems of the classification and the lack of well-observed events exclude direct inference of progenitor characteristics. The absence of hydrogen lines in the observed spectrum, nevertheless, requires restricted evolutionary schemes to produce suitable progenitor stars for core collapse explosions with no hydrogen envelope. New relative statistics among the supernova types are presented which indicate that SN Ib/c are on average brighter than SN II, and with the dense sampling of supernova searches in nearby galaxies, a small intrinsic incidence of SN Ib/c is determined. The small rates might be in conflict with the observed ratio of massive stars in binaries in the Galaxy.
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Chevalier, R. A. « The Early Evolution of Supernova Remnants ». International Astronomical Union Colloquium 101 (1988) : 31–42. http://dx.doi.org/10.1017/s0252921100102076.
Texte intégralRésumé :
AbstractThe density distribution of the supernova ejecta and that of the surrounding medium are the most important parameters for the early evolution of supernova remnants. The distribution of the ejecta depends on the detailed hydrodynamics of the explosion, but the outer parts of a supernova can probably be represented by a steep power law density distribution with radius. Self-similar solutions are especially useful for modeling the interaction of a supernova with its surrounding. The supernova first interacts with mass loss from the progenitor star. Evidence for circumstellar interaction is present in a number of extragalactic supernovae, including SN1987a. The explosions of massive stars probably interact with circumstellar gas for a considerable time while Type Ia supernovae interact more directly with the interstellar medium. X-ray spectroscopy is a good diagnostic for the physical conditions in young supernova remnants and for the composition of the supernova gas.
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Chevalier, Roger A. « Supernovae and their Evolution in a Low Metallicity ISM ». Proceedings of the International Astronomical Union 4, S255 (juin 2008) : 175–81. http://dx.doi.org/10.1017/s1743921308024782.
Texte intégralRésumé :
AbstractObservations of core collapse supernovae and their progenitors generally support expectations of increasing mass loss with increasing initial mass. Mass loss rates are expected to decline at lower metallicity, and there are prospects for directly testing this for the red supergiant progenitors of Type IIP supernovae. However, there are indications that mass loss rates for high mass early type stars may be overestimated and that there are mass loss mechanisms that do not decline at lower metallicity. In this case, there may be supernova emission from strong circumstellar interaction even at low metallicity. Although there is evidence for dust formation in freely expanding ejecta of supernovae, the quantities are relatively small. Another promising site of dust formation is the circumstellar interaction region, but this should occur in only a fraction of supernovae.
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Wells, Azton I., et Michael L. Norman. « Connecting Primordial Star-forming Regions and Second-generation Star Formation in the Phoenix Simulations ». Astrophysical Journal 932, no 1 (1 juin 2022) : 71. http://dx.doi.org/10.3847/1538-4357/ac6c87.
Texte intégralRésumé :
Abstract We introduce the Phoenix Simulations, a suite of highly resolved cosmological simulations featuring hydrodynamics, primordial gas chemistry, primordial and enriched star formation and feedback, UV radiative transfer, and saved outputs with Δt = 200 kyr. We observe 73,523 individual primordial stars within 3313 distinct regions forming 2110 second-generation enriched star clusters by z ≥ 12 within a combined 177.25 Mpc3 volume across three simulations. The regions that lead to enriched star formation can contain ≳150 primordial stars, with 80% of regions having experienced combinations of primordial Type II, hypernovae, and/or pair-instability supernovae. Primordial supernovae enriched 0.8% of the volume, with 2% of enriched gas enriched by later-generation stars. We determine the extent of a primordial stellar region by its metal-rich or ionized hydrogen surrounding cloud; the metal-rich and ionized regions have time-dependent average radii r ≲ 3 kpc. 7 and 17% of regions have r > 7 kpc for metal-rich and ionized radii, respectively. We find that the metallicity distribution function of second-generation stars overlaps that of subsequent Population II star formation, spanning metal-deficient (∼7.94 × 10−8 Z ⊙) to supersolar (∼3.71 Z ⊙), and that 30.5% of second-generation stars have Z > 10−2 Z ⊙. We find that the metallicity of second-generation stars depends on progenitor configuration, with metals from pair-instability supernovae contributing to the most metal-rich clusters; these clusters form promptly after the supernova event. Finally, we create an interpretable regression model to predict the radius of the metal-rich influence of Population III star systems within the first 7–18 Myr after the first Population III stars form in the region.
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Mandel, Ilya, et Bernhard Müller. « Simple recipes for compact remnant masses and natal kicks ». Monthly Notices of the Royal Astronomical Society 499, no 3 (2 octobre 2020) : 3214–21. http://dx.doi.org/10.1093/mnras/staa3043.
Texte intégralRésumé :
ABSTRACT Based on recent results from three-dimensional supernova simulations and semi-analytical parametrized models, we develop analytical prescriptions for the dependence of the mass of neutron stars and black holes and the natal kicks, if any, on the pre-supernova carbon–oxygen core and helium shell masses. Our recipes are probabilistic rather than deterministic in order to account for the intrinsic stochasticity of stellar evolution and supernovae. We anticipate that these recipes will be particularly useful for rapid population synthesis, and we illustrate their application to distributions of remnant masses and kicks for a population of single stars.
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Gehrz, Robert D. « Sources of Stardust in the Galaxy ». Symposium - International Astronomical Union 135 (1989) : 445–53. http://dx.doi.org/10.1017/s0074180900125446.
Texte intégralRésumé :
Observed mass loss rates and Galactic stellar population distributions are used to estimate the rate of injection of stardust into the ISM. M stars and RLOH/IR Stars produce most of the silicates; most of the carbon and SiC comes from carbon stars. WR stars, novae, and supernovae may eject dust with chemical anomalies. There is little observational evidence for a major stellar source of hydrocarbon grains. The Galactic dust ecology considered by comparing stellar dust injection with depletion by star formation and supernova shocks suggests that dust grains are produced by accretion in molecular clouds at 1 to 5 times the stellar rate.
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Eldridge, John J., Robert G. Izzard et Christopher A. Tout. « The Effect of Massive Binaries on Stellar Populations and Supernova Progenitors ». Proceedings of the International Astronomical Union 3, S250 (décembre 2007) : 179–84. http://dx.doi.org/10.1017/s1743921308020474.
Texte intégralRésumé :
AbstractWe have calculated a large set of detailed binary models and used them to test the observed stellar population ratios that compare the relative populations of blue supergiants, red supergiants and Wolf-Rayet stars at different metallicities. We have also used our models to estimate the relative rate of type Ib/c to type II supernovae. We find, with an interacting binary fraction of about two thirds, that we obtain better agreement between our models and observations than with single stars. We discuss the use of models in determining the nature of supernova progenitors and show the surprising result that many type Ib/c supernova progenitors are less luminous and less massive in our models than the observed population of Wolf-Rayet stars.
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Lorimer, D. R., et R. Ramachandran. « Puzzling Pulsars and Supernova Remnants ». International Astronomical Union Colloquium 177 (2000) : 491–92. http://dx.doi.org/10.1017/s0252921100060383.
Texte intégralRésumé :
AbstractThe fact that the majority of the youngest radio pulsars are surrounded by expanding supernova remnants is strong evidence that neutron stars are produced in the supernovae of massive stars. In many cases, the pulsar appears significantly offset from the geometric centre of the supernova remnant, indicating that the neutron star has moved away from the site of the explosion with a substantial space velocity since birth. Here we show that the these offsets show an overwhelming preference for one sign in terms of Galactic longitude, a result that has important implications for the number of genuine associations. The origin of this statistically significant effect may lie in a differential Galactic rotational velocity between stars and gas in the interstellar medium.
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Ramos, Angelu, Jessica Schonhut-Stasik, Anna Payne et Keivan Stassun. « Identifying Habitable-zone Planet Systems Susceptible to Nearby Supernovae ». Research Notes of the AAS 7, no 2 (14 février 2023) : 21. http://dx.doi.org/10.3847/2515-5172/acbaf9.
Texte intégralRésumé :
Abstract We investigate whether any known candidate habitable-zone exoplanet systems could be imperiled by being sufficiently close to a future supernova. Using existing exoplanet databases, we identify 24 stars possessing at least one planet in the star’s habitable zone. We search the Gaia EDR3 catalog for possible core-collapse supernova progenitors within 150 lt-yr of each of these systems, using Pan-STARRS and Gaia EDR3/DR2 colors to identify neighboring stars that are likely to have masses ≥8M ⊙ (i.e., potential supernova Type II progenitors). Within, our sample, we find one instance of a habitable-zone planetary system within 150 lt-yr of a possible Type II supernova progenitor.
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Podsiadlowski, Philipp. « Binary Effects on Supernovae ». Proceedings of the International Astronomical Union 9, S296 (janvier 2013) : 45–52. http://dx.doi.org/10.1017/s1743921313009216.
Texte intégralRésumé :
AbstractHere we review how binary interactions affect the final pre-supernova structure of massive stars and the resulting supernova explosions. (1) Binary-induced mass loss and mass accretion determine the final envelope structure, the mass, radius and chemical composition, which are mainly responsible for the supernova appearance and supernova (sub-)type. (2) Mass loss can also drastically change the core evolution and hence the final fate of a star; specifically, around 10 M⊙, it determines whether a star explodes in a supernova or forms a white dwarf, while for larger masses it can dramatically increase the minimum main-sequence mass above which a star is expected to collapse to a black hole. (3) Mass loss before the supernova directly affects the circumstellar medium (CSM) which can affect the supernova spectrum (e.g. account for the IIn phenomenon), produce powerful radio emission and, in extreme cases, lead to a strong interaction with the supernova ejecta and thus strongly modify the lightcurve shape; it may even be responsible for some of the superluminous supernovae that have recently been discovered.
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Mirabel, I. F. « Stellar progenitors of black holes : insights from optical and infrared observations ». Proceedings of the International Astronomical Union 12, S324 (septembre 2016) : 27–30. http://dx.doi.org/10.1017/s1743921316012576.
Texte intégralRésumé :
AbstractHere are reviewed the insights from observations at optical and infrared wavelengths for low mass limits above which stars do not seem to end as luminous supernovae. These insights are: (1) the absence in archived images of nearby galaxies of stellar progenitors of core-collapse supernovae above 16-18 M⊙, (2) the identification of luminous-massive stars that quietly disappear without optically bright supernovae, (3) the absence in the nebular spectra of supernovae of type II-P of the nucleosynthetic products expected from progenitors above 20 M⊙, (4) the absence in color magnitude diagrams of stars in the environment of historic core-collapse supernovae of stars with ⩾20 M⊙. From the results in these different areas of observational astrophysics, and the recently confirmed dependence of black hole formation on metallicity and redshift of progenitors, it is concluded that a large fraction of massive stellar binaries in the universe end as binary black holes.