A Pre-explosion Effervescent Zone for the Circumstellar Material in SN 2023ixf

I present the effervescent zone model to account for the compact dense circumstellar material(CSM)around the progenitor of the core collapse supernova(CCSN)SN 2023ixf.The effervescent zone is composed of bound dense clumps that are lifted by stellar pulsation and envelope convection to distances of≈tens×au,and then fall back.The dense clumps provide most of the compact CSM mass and exist alongside the regular(escaping)wind.I crudely estimate that for a compact CSM within R_(CSM)≈30 au that contains M_(CSM)≈0.01 M_(⊙),the density of each clump is k_(b)≳3000 times the density of the regular wind at the same radius and that the total volume filling factor of the clumps is several percent.The clumps might cover only a small fraction of the CCSN photosphere in the first days post-explosion,accounting for the lack of strong narrow absorption lines.The long-lived effervescent zone is compatible with no evidence for outbursts in the years prior to the SN 2023ixf explosion and the large-amplitude pulsations of its progenitor,and it is an alternative to the CSM scenario of several-years-long high mass loss rate wind.

The Guest Star of AD185 must have been a Supernova

The ＂guest star＂ of AD185, recorded in the ancient Chinese history the Houhanshu, has been widely regarded as a supernova. However, some authors have suggested that the guest star might have been a comet. It has also been proposed that the record is the concatenation of a nova with a comet made by an early compiler. We have checked the record of the guest star, comparing it with records of comets in the same history. We find that most descriptions of comets clearly indicate motion, whereas the record of the guest star does not. We further argue that the term ＂yan＂ used to describe the star＇s ＂size＂ might be short for yanchuang （seat bed）, and ＂half a yan＂ would be simply as an imaginary figuration of the ancient observer. Moreover, we show that the term ＂hou -year＂ （hou-nian） most probably means the year after next. We argue that the asterism Southern Gate consisted of the stars α andβ Cen. We conclude that the record describing the guest star of AD 185 is completely different from any comet record in the same history, and that it almost certainly was a supernova.

利用SNS平台开展个性化思想政治教育的策略

SNS平台是目前大学生广泛应用的网络平台,在传播方式、呈现方式、交往方式等方面表现出个性化的特点,能够成为高校个性化思想政治教育的有效载体。高校思想政治教育工作应从尊重大学生网络主体、塑造教育者个性化的网络形象、注重教育者与学生的网络交往、坚持网络舆论的社会主义核心价值导向等方面着手,促进高校个性化思想政治教育的发展。

基于SNS的专业技术人员继续教育发展模式初探

SNS与专业技术人员继续教育结合发展优势明显,值得推广和深入研究。尽管这种新型专业技术人员继续教育发展模式具有多样性,但初期发展模式可概括为政府或教育管理部门主导型、行业协会或教育机构主导型和企事业或个体主导型发展模式。基于上述模式,对专业技术人员继续教育提出了发展建议。

SN 2009ip and SN 2010mc as dual-shock Quark-Novae

In recent years a number of double-humped supernovae （SNe） have been discovered. This is a feature predicted by the dual-shock Quark-Nova （QN） model where an SN explosion is followed （a few days to a few weeks later） by a QN explo- sion. SN 2009ip and SN 2010mc are the best observed examples of double-humped SNe. Here, we show that the dual-shock QN model naturally explains their light curves including the late time emission, which we attribute to the interaction between the mixed SN and QN ejecta and the surrounding circumstellar matter. Our model applies to any star （O-stars, luminous blue variables, Wolf-Rayet stars, etc.） provided that the mass involved in the SN explosion is ~ 20 Mo which provides good conditions for forming a QN.

Optical observations of the broad-lined type Ic supernova SN 2012ap

Abstract The optical observations of the type Ic supernova （SN lc） SN 2012ap in NGC 1729 are presented. A comparison with other SNe Ic indicates that SN 2012ap is highly reddened （with E（B - V）host-0.8 mag） and may represent one of the most luminous SNe Ic ever observed, with an absolute V-band peak magnitude of - 19.3±0.5 mag after extinction correction. The near-maximum-light spectrum shows wide spectral features that are typical of broad-lined SNe Ic. One interesting feature in the spectrum is the appearance of some narrow absorption features that can be at- tributed to the diffuse interstellar bands, consistent with the large reddening inferred from the photometric method. Based on the light curves and the spectral data, we esti- mate that SN 2012ap produced a 56Ni mass of - 0.3 -b 0.1M in the explosion, with an ejecta mass of 2.4^＋0.7 -0.7M and a kinetic energy of EK=1.1^＋0.4 -0.4×10^52 erg. The properties of its progenitor are also briefly discussed.

The Relativistic Three-Dimensional Evolution of SN 1987A

The high velocities observed in supernovae require a relativistic treatment for the equation of motion in the presence of gradients in the density of the interstellar medium. The adopted theory is that of the thin layer approximation. The chosen medium is auto-gravitating with respect to an equatorial plane. The differential equation which governs the relativistic conservation of momentum is solved numerically and by recursion. The asymmetric field of relativistic velocities as well the time dilation is plotted at the age of 1 yr for SN 1987A.

Three Dimensional Evolution of SN 1987A in a Self-Gravitating Disk

The introduction of an exponential or power law gradient in the interstellar medium (ISM) allows to produce an asymmetric evolution of the supernova remnant (SNR) when the framework of the thin layer approximation is adopted. Unfortunately both the exponential and power law gradients for the ISM do not have a well defined physical meaning. The physics conversely is well represented by an isothermal self-gravitating disk of particles whose velocity is everywhere Maxwellian. We derived a law of motion in the framework of the thin layer approximation with a control parameter of the swept mass. The photon’s losses, which are often neglected in the thin layer approximation, are modeled trough velocity dependence. The developed framework is applied to SNR 1987A and the three observed rings are simulated.

Modeling the fast optical transient SN 2019bkc/ATLAS19dqr with a central engine and implication for its origin

Modern wide-field high-cadence surveys have revealed the significant diversity of optical transient phenomena in their luminosity and timescale distributions,which led to the discovery of some mysterious fast optical transients(FOTs).These FOTs can usually rise and decline remarkably in a timescale of a few days to weeks,which are obviously much rapider than ordinary supernovae.SN2019 bkc/ATLAS19 dqr is one of the fastest detected FOTs so far and,meanwhile,it was found to be unassociated with a host galaxy.These discoveries provide a good chance to explore the possible origins of FOTs.So,we model the light curves of SN 2019 bkc in details.It is found that SN 2019 bkc can be well explained by the thermal emission of an explosion ejecta that is powered by a long-lasting central engine.The engine could be a spinning-down millisecond magnetar or a fallback accretion onto a compact object.Combining the engine property,the mass of the ejecta,and the hostlessness of SN 2019 bkc,we suggest that this FOT is likely to originate from a merger of a white dwarf and a neutron star.

Study the Radial Expansion of SN 1987A Using Counting Pixels Method

Physical properties of supernova 1987A were investigated including: Expansion velocity;Current mass;Radius;Temperature and the Rate of the expansion by applying Counting Pixels Method (CPM) in comparison with the application of the Povida and Self-Similar Solution theoretical models which in forced the idea for adopting such a model to be applied for supernova type II. Then tow results are found to be in a good agreement with the Self-Similar solution model rather than that of Povida model. The high density of the region that surrounded the exploding system acting as decelerating parameter and down the expansion velocity of the supernova from 3900 km·s-1 to 1200 km·s-1 during the past 23 years from the explosion, with a current size equal 0.39 pc, and with an expansion rate of 0.41 per a year.

The peculiar case of the “double-humped” super-luminous supernova SN 2006oz

SN 2006oz is a super-luminous supernova with a mysterious bright precursor that has resisted explanation in standard models.However,such a precursor has been predicted in the dual-shock quark nova model of super-luminous supernovae–the precursor is the supernova event while the main light curve of the super-luminous supernova is powered by the Quark-Nova（explosive transition of the neutron star to a quark star）.As the supernova is fading,the Quark-Nova re-energizes the supernova ejecta,producing a＂double-humped＂light curve.We show that the quark nova model successfully reproduces the observed light curve of SN 2006oz.

心理学视角下社交网络用户个体行为分析

以社交网络的典型代表Facebook为例,以社交网络用户个体行为为着眼点,从个体使用社交网络的动机、社交网络用户个体行为的主要表现及其影响因素和结果变量四个方面,梳理国外心理学领域有关社交网络的最新研究成果。今后研究可以在社交网络用户个体行为的测量、样本代表性、线上和线下社交网络的交互作用、具体人格特质变量的预测作用以及对社交网络功能的动态考察等方面推进已有研究。

社交网络大数据商业化开发利用中的个人隐私保护

社交网络大数据商业化开发利用主要有五种模式,文章针对各种模式中个人隐私泄露的主要原因,提出保护策略:每位社交网络用户要高度重视,规范网络社交行为,提高安防技能;尽快制定专门法律并完善现有法律;社交网络服务提供商应遵守行业安全规范,加强自律;尽快出台社交软件安全开发规范,强化安全测评,加强信息安全技术应用研究;尽快制定社会信息伦理道德规范,提高公民信息素养;设立网络安全监控警察,防范非法攻击。

南岭某些钨锡铍矿床中单个流体包裹体成分初步研究

使用激光拉曼光谱测定了南岭三个典型钨锡铍矿床的水晶、绿柱石、锡石和香花石中单个流体包裹体气、液相的成分,除H2O外,气、液相中均含有大量的CO2,烃类普遍存在,其中以丙烯最重要。南岭W-Sn矿床成矿流体可能是花岗质岩浆在岩浆-热液过渡阶段不混溶的流体分离形成的。在成矿晚期,围岩热接触变质释放出的N2连同循环的大气水进入成矿流体。

Energy Conservation in the Thin Layer Approximation: I. The Spherical Classic Case for Supernovae Remnants

The thin layer approximation applied to the expansion of a supernova remnant assumes that all the swept mass resides in a thin shell. The law of motion in the thin layer approximation is therefore found using the conservation of momentum. Here we instead introduce the conservation of energy in the framework of the thin layer approximation. The first case to be analysed is that of an interstellar medium with constant density and the second case is that of 7 profiles of decreasing density with respect to the centre of the explosion. The analytical and numerical results are applied to 4 supernova remnants: Tycho, Cas A, Cygnus loop, and SN 1006. The back reaction due to the radiative losses for the law of motion is evaluated in the case of constant density of the interstellar medium.

社交网络中个体价值分析

社交网络中个体价值分析,就是利用网络爬虫抓取社交网络中数据,对数据过滤分析,抽象成图结构,发现排名最高的节点(个体)。本文基于Page Rank算法模型,应用"黄金分割线"方法和"二八定律"对其进行改进,并用在社交网络中,定义以人为核心的个体价值,这样Page Rank模型就有了新的应用领域,同时也有了一个新的名字"People Rank"。本文将复杂的社交网络抽象成一种图结构,图中节点代表用户,图中边的链入链出代表了用户之间的"粉丝"和"关注"关系。利用"People Rank"模型,构建矩阵,对矩阵进行迭代计算,最后得到一个收敛的结果,根据结果的大小确定在社交网络中个体的重要性。

Energy Conservation in the Thin Layer Approximation: IV. The Light Curve for Supernovae

The light curves (LC) for Supernova (SN) can be modeled adopting the conversion of the flux of kinetic energy into radiation. This conversion requires an analytical or a numerical law of motion for the expanding radius of the SN. In the framework of conservation of energy for the thin layer approximation, we present a classical trajectory based on a power law profile for the density, a relativistic trajectory based on the Navarro-Frenk-White profile for the density, and a relativistic trajectory based on a power law behaviour for the swept mass. A detailed simulation of the LC requires the evaluation of the optical depth as a function of time. We modeled the LC of SN 1993J in different astronomical bands, the LC of GRB 050814 and the LC GRB 060729 in the keV region. The time dependence of the magnetic field of equipartition is derived from the theoretical formula for the luminosity.

Relativistic Motion with Viscosity: II Stokes’s Law of Resistance

The deduction of a relativistic and mildly relativistic equation of motion in the presence of a drag force proportional to the velocity is presented. The obtained results are used to model the trajectory of the supernova SN1993J and the light curves of gamma-ray bursts.

Energy Conservation in the Thin Layer Approximation: III. The Spherical Relativistic Case for Supernovae

The theory of the conservation of energy in the thin layer approximation has been extended to special relativity. Four models for the density of the circumstellar medium are analyzed, which are represented by constant, power law, exponential and Emden (n = 5) profile for density. The astrophysical results are presented in a numerical way, except for a Taylor expansion of the four trajectories in the surrounding of the origin. The free parameters of the models are particularized for SN1993j, for which the radius versus time is known. Some evaluations on the time dilation are presented.

The surviving companions in type Ia supernova remnants

The single-degenerate(SD)model is one of the most popular progenitor models of type Ia supernovae(SNe Ia),in which the companion star can survive after an SN Ia explosion and show peculiar properties.Therefore,searching for the surviving companion in type Ia supernova remnants(SNRs)is a potential method to verify the SD model.In the SN 1604 remnant(Kepler’s SNR),although Chandra X-ray observation suggests that the progenitor is most likely a WD+AGB system,the surviving companion has not been found.One possible reason is rapid rotation of the white dwarf(WD),causing explosion of the WD to be delayed for a spin-down timescale,and then the companion evolved into a WD before the supernova explosion,so the companion is too dim to be detected.We aim to verify this possible explanation by carrying out binary evolution calculations.In this paper,we use Eggleton’s stellar evolution code to calculate the evolution of binaries consisting of a WD+red giant(RG).We assume that the rapidly rotating WD can continuously increase its mass when its mass exceeds the Chandrasekhar mass limit(MCh=1.378 M_⊙)until the mass-transfer rate decreases to be lower than a critical value.Eventually,we obtain the final masses of a WD in the range 1.378 M_⊙ to 2.707 M_⊙.We also show that if the spin-down time is less than 10~6yr,the companion star will be very bright and easily observed;but if the spin-down time is as long as^10~7 yr,the luminosities of the surviving companion would be lower than the detection limit.Our simulation provides guidance in hunting for the surviving companion stars in SNRs,and the fact that no surviving companion has been found in Kepler’s SNR may not be definite evidence disfavoring the SD origin of Kepler’s SN.