The Mysterius Fate of Stars (Past, Present and Future of the Universe)

The research on the collapse of stars, due to Gravity, after the depletion of the fusion fuel, engaged a number of famous guys as Eddington, Chandrasekhar, Schwarzschild and Oppenheimer in the years around 1910-1050. During this period, Einstein was writing his field equation of general relativity (1923), Fermi, in a famous letter to Pauli, proposed the neutrino in beta decay theory (1930), Chadwick found the neutron, that granted him the Nobel price (1935) and Hubble (1929) proved that the Universe was expanding. As a result of that golden age, we remain with a lot of unsolved questions, due to the poor knowledge of the nature of the strong Nuclear Interaction of Gravity that controls the whole Universe. We have made an investigation on the nature of nuclear bond and gravitational attraction on the basis of available data and as a follow-up of Fermi famous research on Neutrino. Using this background, we hope to be able to explain or give some light to the evolution of stars, to the strange objects and phenomena captured or perceived by astronomers in the sky and speculated by theoretical physicists.

The Nuclear Clock Correction for Universal Gravitation

Science is losing some fixed references shifting from universality to relativity: time and space become space time, the meter is related to the velocity of light and the second is fixed by the ticketing of a Cesium atom. In the case of Gravity, Nature was so friendly to Newton to allow him the writing of the Universal Gravitational Law, that changed the view of the Universe for the last three centuries. However, the way matter generates Gravity was unknown to Newton and the problem is still nowadays ignored by most scientists and remains the ultimate question mark of physics. We paid attention to the ticketing of all existing nuclides and found that the parameters of the neutronproton transformations are so precise, in describing these reactions, that can be considered universal constants. Instead, the emitted neutrino flux Fo is almost constant with a mean value of 6.668E20 neutrino per gram and second over the wide range of all nuclides with some deviation for lighter nuclei. This is the reason why Newton was able to find his Universal Gravitational Law and allows us today to state a relation of this flux with the Gauss constant G on the basis of nuclear properties. Moreover, it explains the mechanism that bodies use for their mutual attraction with a simplification of the three-body problem in celestial bodies computation. We have to remember that Newton model, with a fixed gravitational Gauss constant G, or the equivalent with a fixed neutrino flux Fo, have been used for the determination of the mass of the celestial bodies in motion with the implicit assumption that the gravitational and inertial mass are the same. In this paper we recognize the big difference in composition of the Sun and the gaseous planets compared to the terrestrial ones and show how the relatively small difference of the neutrino flux can change our vision of the Universe.

Generating Baikal-GVD high energy cascade-like neutrino events with a GEANT4-based simulation toolkit

Using the GEANT4 and Cosmic Ray Monte Carlo(CRMC)software packages,we developed a new simulation toolkit for astrophysical neutrino telescopes.By configuring the Baikal-GVD detector and comparing the vertex position and direction of incident particles,as well as the channel-by-channel signals,to the events detected by Baikal-GVD,we successfully generated 13 high-energy cascade neutrino events with the toolkit.Our analysis revealed a systematic offset between the reconstructed shower position and the true interaction position,with a distance close to the scale of the shower maximum of−0.54±1.29 m.We achieved a good linear relationship between the photoelectron number of neutrino events obtained by simulation and the real data measured by Baikal-GVD.The simulation toolkit could serve as a reliable basis for studying the performance of astrophysical neutrino telescopes.

宇宙线天体物理中的几个重要问题

宇宙线是来自宇宙空间的高能粒子流，研究宇宙线的起源、加速、传播机制及其所涉及的天体物理和宇宙学过程是宇宙线天体物理研究的重要内容。本文介绍并讨论其中几个涉及物理学一些基本问题的重要课题的研究现状及前景，其中包括极高能宇宙线的观测研究，太阳中微子能谱的实时测量，宇宙线中新粒子的搜寻等。

Exploring the Dynamic X-ray Universe:Scientific Opportunities for the Einstein Probe Mission

Time-domain astrophysics will enter a golden era towards the end of this decade with the advent of major facilities across the electromagnetic spectrum and in the multi-messenger realms of gravitational wave and neutrino.In the soft X-ray regime,the novel micro-pore lobster-eye optics provides a promising technology to realise,for the first time,focusing X-ray optics for wide-angle monitors to achieve a good combination of sensitivity and wide field of view.In this context Einstein Probe,a soft X-ray all-sky monitor mission,was proposed and selected as a candidate mission of priority in the space science programme of the Chinese Academy of Sciences.This paper reviews the most important science developments and key questions in this field towards 2020 and beyond,and how to achieve them technologically.It also introduces the Einstein Probe mission,including its key science goals and mission definition,as well as some of the key technological issues.

中微子天文学和X射线天文学的诞生

本文介绍了 2 0 0 2年诺贝尔物理学奖的两项研究成果 :捕获了宇宙中微子 ;发现了宇宙X射线源 .

超新星(续)

超新星爆炸是发生在宇宙空间中极为壮观、丰富多彩和引人入胜的重要现象,涉及许多有趣的、尚待探索的物理学研究领域和天体物理学及宇宙学若干相关分支的重要应用.本文试图描述超新星现象研究在各方面的重要意义,提供基本观测事实和理论框架信息以及介绍我们正在从事的部分相关研究工作.

NEUTRINO BEAM LINES AT HIGH-ENERGY PROTON SYNCHROTRONS

Revised September 2013 with numbers verified by representatives of the synchrotrons （contact C.-J. Lin, LBNL）. For existing （future） neutrino beam lines the latest achieved （design） values are given.

Dynamical Behavior of Core ^3He Nuclear Reaction-Diffusion Systems and Sun＇s Gravitational Field

The coupling of the sun's gravitational field with processes of diffusion and convection exerts a significant influence on the dynamical behavior of the core 3He nuclear reaction-diffusion system. Stability analyses of the system are made in this paper by using the theory of nonequilibrium dynamics. It is showed that, in the nuclear reaction regions extending from the center to about 0.38 times of the radius of the sun, the gravitational field enables the core 3He nuclear reaction-diffusion system to become unstable and, after the instability, new states to appear in the system have characteristic of time oscillation. This may change the production rates of both 7Be and 8B neutrinos.

Neutrino astronomy： An update

Detecting neutrinos associated with the still enigmatic sources of cosmic rays has reached a new watershed with the completion of IceCube, the first detector with sensitivity to the anticipated fluxes. In this review, we will briefly revisit the rationale for constructing kilometer-scale neutrino detectors and summarize the status of the field.

Implication from GRB 221009A:Can TeV emission come from the GRB prompt phase?

Recently,the B.O.A.T.(“brightest of all time”)gamma-ray burst,dubbed GRB 221009A,was detected by various instruments.Unprecedentedly,the GRB presented very-high-energy(VHE,energy above 0.1 Te V)gamma-ray emission with energy extending above 10 Te V,as reported by the Large High Altitude Air Shower Observatory(LHAASO).We here demonstrate that the VHE and especially>10 Te V emission may originate from the internal hadronic dissipation of the GRB,without the need of invoking any exotic processes as suggested by some previous studies.The possible prompt origin of LHAASO photons may imply the first detection of the GRB prompt phase in the VHE regime.We also discuss the constraints on the properties of the GRB ejecta from multiwavelength and multi-messenger observations,which favors a magnetically dominated GRB ejecta.The suggested Poynting-flux-dominated GRB ejecta in this work supports the Blandford&Znajek(BZ)mechanism as the possible central engine model of GRB,as well as the possible strong magnetic dissipation and acceleration.

原子核天体物理简介

文章对原子核天体物理这一门重要交叉学科作了简单的介绍,并以一批获得诺贝尔物理奖的成果为线索,重点描述了大爆炸宇宙学、太阳中微子、恒星演化及其终点以及原子核物理与元素的起源等方面的进展与挑战。

河外极高能宇宙线的起源

由于大型宇宙线探测器Pierre Auger,Telescope Array等的观测,极高能宇宙线(能量大于1018 e V的宇宙线)的研究取得了很大进展,包括探测到高能能谱变陡,与河外天体源的可能相关性,以及化学成分组成等.然而这些宇宙线的起源天体仍未知.本文将评述河外极高能宇宙线起源的候选天体,包括伽玛射线暴,活动星系核,巨超新星等.同时我们从多信使角度(包括高能中微子,伽玛光子的观测),探讨这些天体是河外极高能宇宙线起源天体的可能性.

TeV astronomy

With the successful realization of the current-generation of ground-based detectors, TeV Astronomy has entered into a new era. We review recent advances in VHE astronomy, focusing on the potential of Imaging Atmospheric Cherenkov Telescopes （IACTs）, and highlight astrophysical implications of the results obtained within recent years.

双中子星并合的中微子信号

2017年8月17日,LIGO/Virgo首次探测到了双中子星并合事件的引力波信号,随后多波段的跟进观测获得了GW170817事件的多波段"全息"图像并确认源头在40 Mpc外的NGC4993星系,但颇为遗憾的是(尽管与理论预期符合)当时全球运行中的中微子探测器都没有探测到与GW170817相关联的中微子。普遍认为,热中微子在双星引力潮汐撕裂绕行阶段就会产生,在并合事件后的十几毫秒内达到峰值;若并合中心产物为伽马射线暴或者稳定的磁星,还会在并合的即刻至数天内产生超高能中微子。因此,中微子信号不仅可以辅助研究并合后的产物环境,还可以在天文尺度上研究中微子的基本性质和寻找粒子物理标准模型之外的新物理。即使只探测到一个热中微子事件,也可以获得热中微子的能谱标度信息和诊断并合后十几毫秒内星体本身和周围环境的物理参数。另外,因为引力波以光速传播,通过热中微子信号相对引力波信号的时延,可限制中微子的绝对质量。若探测到延迟的高能中微子信号,除了可以清楚地证明双中子星并合的中心产物是磁星,还可以研究并合产物附近的磁场环境和宇宙射线加速机制。

Some highlights of the Gamma-ray first four years of the Fermi Space Telescope

The Fermi Gamma-ray Space Telescope, formerly called GLAST, measures the cosmic gamma-ray flux in the energy range 8 keV to 〉 300 GeV. In addition to breakthrough capabilities in energy coverage and localization, the very large field of view enables observations of 20~ of the sky at any instant, and the entire sky on a timescale of a few hours. With its launch in 2008, Fermi opens a new and important window on a wide variety of phenomena, including pulsars, black holes and active galactic nuclei, gamma-ray bursts, supernova remnants and the origins of cosmic rays, and searches for hypothetical new phenomena such as particle dark matter annihilations. A brief overview and selected science highlights from the first four years are provided.