Type Ia supernovae (SNe Ia) can be used as the standard candlelight to determine the cosmological distances because they are thought to have a uniform fuel amount. Recent observations of several overluminous SNe Ia suggest that the white dwarf masses at supernova explosion may significantly exceed the canonical Chandrasekhar mass limit. These massive white dwarfs may be supported by rapid differential rotation. Based on single degenerate model and the assumption that the white dwarf would differentially rotate when the accretion rate $\dot{M}>3\times10^{-7}M_{\odot}\rm yr^{-1}$, we have calculated the evolutions of close binaries consisting of a white dwarf and a normal companion. To include the effect of rotation, we introduce an effective mass $M_{\rm eff}$ for white dwarfs. For the donor stars with two different metallicities $Z=0.02$ and 0.001, we present the distribution of the initial donor star masses and the orbital periods of the progenitors of super-Chandrasekhar mass SNe Ia. The calculation results indicate that, for an initial massive white dwarf of $1.2M_{\odot}$, a considerable fraction of SNe Ia may result from super-Chandresekhar mass white dwarfs, but very massive ($>1.7 M_{\sun}$) white dwarfs are difficult to form, and none of them could be found in old populations. However, super-Chandrasekhar mass SNe Ia are very rare when the initial mass of white dwarfs is $1.0M_{\odot}$. Additionally, SNe Ia in low metallicity environment are more likely to be homogeneous.
The precise progenitor system of type Ia supernovae (SNe Ia), whether it is a white dwarf (WD) close to the Chandrasekhar limit or substantially less massive, has been a matter of debate for decades. Recent research by our group on the accretion and simmering phases preceding the explosion of a massive WD has shown that the central density at thermal runaway lies in the range $(3.6-6.3)\times10^9$ g cm$^{-3}$ for reasonable choices of accretion rate onto the WD and progenitor metallicity. In this work, we have computed one-dimensional simulations of the explosion of such WDs, with special emph…
Observational Predictions for Sub-Chandrasekhar Mass Explosions: Further Evidence for Multiple Progenitor Systems for Type Ia Supernovae
本文介绍了亚阿布拉塞卡质量白矮星（WD）爆炸的数值参数测量。碳-氧WDs吸积氦壳层有可能在亚克拉塞卡质量状态下爆炸。以往的研究表明，氦壳层的点火既可以直接点燃核壳界面处的WD，也可以将冲击波传播到核中，引起中心点火。我们研究了0.6 - 1.2 M $_\odot$的WD与0.01，0.05和0.08 M $_\odot$的氦壳层的爆炸。不同的观测签名的sub-Brachasekhar质量WD爆炸预测两类壳的大小。较厚的壳层模型显示出早期的通量过剩，这是由于氦壳层的灰烬中存在放射性物质造成的，并且由于这些灰烬在紫外线中通过光谱的蓝色部分产生了显着的线覆盖而导致红色。薄壳模型再现了几个典型的Ia型超新星特征。我们确定了硅II速度和光度之间的关系，这是第一次，确定了一个子类的观察到的超新星是符合这些模型。这一亚类的大气层中不含碳元素。我们认为，高速和正常速度的Ia型超新星之间的选择性完全消光比的差异不是由于这些事件周围的尘埃的性质的差异，而是一个人工制品的应用一个单一的消光校正两个本质上不同的超新星种群。
The recently observed diversity of Type Ia supernovae (SNe Ia) has motivated us to conduct the theoretical modeling of SNe Ia for a wide parameter range. In particular, the origin of Type Iax supernovae (SNe Iax) has been obscure. Following our earlier work on the parameter dependence of SN Ia models, we focus on SNe Iax in the present study. For a model of SNe Iax, we adopt the currently leading model of pure turbulent deflagration (PTD) of near-Chandrasekhar mass C+O white dwarfs (WDs). We carry out 2-dimensional hydrodynamical simulations of the propagation of deflagration wave, which leave…
We use non-local thermal equilibrium radiative transport modeling to examine observational signatures of sub-Chandrasekhar mass double detonation explosions in the nebular phase. Results range from spectra that look like typical and subluminous Type Ia supernovae (SNe) for higher mass progenitors to spectra that look like Ca-rich transients for lower mass progenitors. This ignition mechanism produces an inherent relationship between emission features and the progenitor mass as the ratio of the nebular [Ca II]/[Fe III] emission lines increases with decreasing white dwarf mass. Examining the [Ca…
Supernova Ia are bright explosive events that can be used to estimate cosmological distances, allowing us to study the expansion of the Universe. They are understood to result from a thermonuclear detonation in a white dwarf that formed from the exhausted core of a star more massive than the Sun. However, the possible progenitor channels leading to an explosion are a long-standing debate, limiting the precision and accuracy of supernova Ia as distance indicators. Here we present HD265435, a binary system with an orbital period of less than a hundred minutes, consisting of a white dwarf and a h…
First-Principles Turbulence-Driven Deflagration-to-Detonation Transition Mechanism for Near-Chandrasekhar Mass White Dwarf Progenitors
University of Massachusetts Dartmouth（麻省大学达特茅斯分校）；University of Connecticut, School of Mechanical, Aerospace, and Manufacturing Engineering（康涅狄格大学机械、航空航天与制造工程学院）；Naval Research Laboratory, Laboratories for Computational Physics & Fluid Dynamics（海军研究实验室计算物理与流体动力学实验室）；University of Maryland, Physical Sciences Complex, Stadium Drive（马里兰大学）；Universität Heidelberg, Zentrum für Astronomie, Institut für Theoretische Astrophysik（海德堡大学天文学中心理论天体物理学研究所）
Chandrasekhar and sub-Chandrasekhar models for the X-ray emission of Type Ia supernova remnants (I): Bulk properties
Ia型超新星起源于双星系统中碳氧白矮星的爆炸，但其祖先的确切性质仍然难以捉摸。Ia型超新星遗迹的整体性质，如X射线谱中Fe K $α$混合物的半径和质心能量，是由超新星喷出物和周围介质的性质决定的。我们模拟Ia型超新星喷出物和一系列均匀的环境介质密度在一个维度上的年龄为5000年之间的相互作用的Brachasekhar和子Brachasekhar模型。我们从这些超新星遗迹模型中生成合成X射线光谱，并将它们在不同膨胀年龄下的体积性质与\textit{Chandra}和\textit{Suzaku}的X射线观测结果进行比较。我们发现，我们的模型可以成功地再现大多数观察到的残余物的散装性能，这表明Ia型SN祖细胞不修改他们的周围环境显着的几个PC的规模。环境介质密度和膨胀年龄是我们模型中体积性质多样性的主要贡献者。对于大块残留物的性质，克拉塞卡和亚克拉塞卡的祖先做出了类似的预测，但是对X射线光谱的详细拟合具有区分爆炸能量和祖先情景的能力。
Type Ia supernovae (SNe Ia) are likely the thermonuclear explosions of carbon-oxygen (CO) white-dwarf (WD) stars, but their progenitor systems remain elusive. Recently, Sharon & Kushnir (2022) used The Zwicky Transient Facility Bright Transient Survey to construct a synthesized $^{56}$Ni mass, $M_\text{Ni56}$, distribution of SNe Ia. They found that the rate of low-luminosity ($M_\text{Ni56}\approx0.15\,M_{\odot}$) SNe Ia is lower by a factor of $\sim10$ than the more common $M_\text{Ni56}\approx0.7\,M_{\odot}$ events. We here show that in order for the double-detonation model (DDM, in which a…
Modified Einstein's gravity to probe the sub- and super-Chandrasekhar limiting mass white dwarfs: a new perspective to unify under- and over-luminous type Ia supernovae
Due to the increasing number of observations Type Ia supernovae are nowadays regarded as a heterogeneous class of objects consisting of several subclasses. One of the largest of these is the class of Type Iax supernovae (SNe Iax) which have been suggested to originate from pure deflagrations in CO Chandrasekhar-mass white dwarfs (WDs). Although a few deflagration studies have been carried out, the full diversity of the class is not captured yet. We therefore present a parameter study of single-spot ignited deflagrations with varying ignition locations, central densities, metallicities and comp…
Study of the double detonation Type Ia supernova scenario, in which a helium shell detonation triggers a carbon core detonation in a sub-Chandrasekhar-mass white dwarf, has experienced a resurgence in the past decade. New evolutionary scenarios and a better understanding of which nuclear reactions are essential have allowed for successful explosions in white dwarfs with much thinner helium shells than in the original, decades-old incarnation of the double detonation scenario. In this paper, we present the first suite of light curves and spectra from multi-dimensional radiative transfer calcula…
The radiosotope $^{44}$Ti is produced through $α$-rich freezeout and explosive helium burning in type Ia supernovae (SNe Ia). In this paper, we discuss how the detection of $^{44}$Ti, either through late-time light curves of SNe Ia, or directly via gamma rays, can uniquely constrain the origin of SNe Ia. In particular, building upon recent advances in the hydrodynamical simulation of helium-ignited double white dwarf binaries, we demonstrate that the detection of $^{44}$Ti in a nearby SN Ia or in a young galactic supernova remnant (SNR) can discriminate between the double-detonation and double…
Off-centre ignition of sub-Chandrasekhar white dwarfs does not resolve the tension with the observed $t_0$-$M_{\rm{Ni}56}$ relation of type Ia supernovae
This paper presents a database of the spectroscopic- and photometric- spectral energy distributions (spec-SEDs and phot-SEDs) of the progenitors of core-collapse supernovae (CCSNe). Both binary- and single-star progenitors are included in the database. The database covers the initial metallicity ($Z$) range of 0.0001--0.03, mass range of 8--25 \dsm{}, binary mass ratio range of 0--1, and orbital period range of 0.1--10000\,days. The low-resolution spec-SEDs and phot-SEDs of single- and binary-star CCSN progenitors are included in the database. These data can be used for studying the basic para…
Stars in the mass range from 8 to 10 solar masses 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, 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 solar masses, …
Recent observational evidence has demonstrated that white dwarf (WD) mergers are a highly efficient mechanism for mass accretion onto WDs in the galaxy. In this paper, we show that WD mergers naturally produce highly-magnetized, uniformly-rotating WDs, including a substantial population within a narrow mass range close to the Chandrasekhar mass ($M_{\rm Ch}$). These near-$M_{\rm Ch}$ WD mergers subsequently undergo rapid spin up and compression on a $\sim 10^2$ yr timescale, either leading to central ignition and a normal SN Ia via the DDT mechanism, or alternatively to a failed detonation and…
We present nebular spectra of the Type Ia supernova (SN Ia) SN 2019yvq, which had a bright flash of blue and ultraviolet light after exploding, followed by a rise similar to other SNe Ia. Although SN 2019yvq displayed several other rare characteristics such as persistent high ejecta velocity near peak brightness, it was not especially peculiar and if the early "excess" emission were not observed, it would likely be included in cosmological samples. The excess flux can be explained by several different physical models linked to the details of the progenitor system and explosion mechanism. Each …
What the progenitors of Type Ia supernovae (SNe Ia) are, whether they are near-Chandrasekhar mass or sub-Chandrasekhar mass white dwarfs, has been the matter of debate for decades. Various observational hints are supporting both models as the main progenitors. In this paper, we review the explosion physics and the chemical abundance patterns of SNe Ia from these two classes of progenitors. We will discuss how the observational data of SNe Ia, their remnants, the Milky Way Galaxy, and galactic clusters can help us to determine the essential features where numerical models of SNe Ia need to matc…
Erratum: Progenitor-explosion connection and remnant birth masses for neutrino-driven supernovae of iron-core progenitors (2012, ApJ, 757, 69)
对流体动力学结果的错误解释导致Ugliano等人（2012）对后备质量的错误确定，这也（在较小的水平上）影响了该论文中提供的中子星质量。Ertl et al.（2015）和Sukhbold et al.（2015）在后续工作中已经解决并纠正了这个问题。因此，建议读者使用后两篇出版物的新数据。在本勘误表的其余部分，我们详细介绍了新旧回退结果的差异，并解释了Ugliano等人（2012）原始分析中错误的起源。
Evidence for sub-Chandrasekhar-mass progenitors of Type Ia supernovae at the faint end of the width-luminosity relation
低光度Ia型超新星（SNe Ia）的光变曲线演化速度更快，这表明它们可能是由质量低于克拉塞卡质量（$M_{\rm Ch}$）的白矮星（WD）的祖先爆炸造成的。在这里，我们提出了一维非LTE时间相关的辐射传输模拟的纯中心爆炸的碳氧WD与质量（$M_\rm{tot}$）之间的0.88 M $_{\odot}$和1.15 M $_{\odot}$，和一个$^{56}\rm{Ni}$产率之间的0.08 M $_{\odot}$和0.84 M $_{\odot}$。与$M_{\rm Ch}$模型相比，它们较低的喷出物密度导致早期光度更快地增加，并增强了$γ$射线逃逸分数超过最大光。因此，它们的热光变曲线显示较短的上升时间和较大的最大后下降率。此外，在给定的$^{56}\rm{Ni}$质量下，较高的$M(^{56}\rm{Ni})/M_\rm{tot}$比率增强了发光度较低的模型的光谱形成区域中的温度和电离水平，从而在最大光下产生更蓝的颜色，并且$B-V$颜色的最大后演化更快。对于在峰值时比$M_B\approx -18.5$等暗的次$M_{\rm Ch}$模型，较大的热辐射衰减和较快的颜色演变导致较大的$B$带最大后衰减率$ΔM_{15}(B)$。特别是，我们以前发表的所有$M_{\rm Ch}$模型（标准和脉动延迟爆轰）都局限于$ΔM_{15}(B) < 1.4$等，而$M_\rm{tot…
Excavating the Explosion and Progenitor Properties of Type IIP Supernovae via Modelling of their Optical Lightcurves
IIP型超新星（SNe）的前身是红超巨星，但它们的性质还没有很好的确定。我们采用流体动力学模型研究了八个IIP型超新星的爆炸特征，以及它们的祖先星的性质。我们使用{ \sc MESA}恒星演化程序建立演化模型，将这些模型分解，并使用{ \sc STELLA}程序模拟光学光变曲线。我们拟合的光学光变曲线，Fe II 5169日冕速度，光球速度，观测数据。最近的研究表明，IIP SNe型的祖细胞具有不超过$\sim18$ M $_{\odot}$的零年龄主序列（ZAMS）质量。我们的拟合给出了7颗超新星的祖星ZAMS质量$\leq18$ M $_{\odot}$。在以前的祖质量估计存在，从各种来源，如流体动力学建模，多波长观测，或半分析计算，我们的建模一般倾向于较低的质量值。这一结果与以前的流体动力学模拟结果相反，但与使用广义相对论辐射流体动力学代码获得的结果一致。我们确实发现了一个事件，SN 2015 ba，有一个质量接近24 M $_{\odot}$的祖先，尽管我们无法很好地拟合它。我们还推导出再现光变曲线的尾部所需的$^{56}$ Ni的量，并发现值通常大于以前的估计。总的来说，我们发现很难用一个单一的参数来描述爆炸，需要一系列的参数。
We infer the progenitor mass distribution for 22 historic core-collapse supernovae (CCSNe) using a Bayesian hierarchical model. For this inference, we use the local star formation histories to estimate the age for each supernova (SN). These star formation histories often show multiple bursts of star formation; our model assumes that one burst is associated with the SN progenitor and the others are random bursts of star formation. The primary inference is the progenitor age distribution. Due to the limited number of historic SNe and highly uncertain star formation at young ages, we restrict our…
Recent observations of Type Ia supernovae (SNe Ia) have shown diversified properties of the explosion strength, light curves and chemical composition. To investigate possible origins of such diversities in SNe Ia, we have presented multi-dimensional hydrodynamical study of explosions and associated nucleosynthesis in the near Chandrasekhar mass carbon-oxygen (CO) white dwarfs (WDs) for a wide range of parameters (Leung and Nomoto 2018 ApJ). In the present paper, we extend our wide parameter survey of models to the explosions of sub-Chandrasekhar mass CO WDs. We take the double detonation model…
