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Revisiting the event rate of short GRBs and estimating their detectable number within the Advanced LIGO horizon

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Research in Astronomy and Astrophysics 2019年第8期19卷 123-130页

作者： Hao-Yang Liu yun-wei yu Institute of Astrophysics Central China Normal University

The redshift and luminosity distributions of 36 Swift short gamma-ray bursts(GRBs) are fitted by connecting their event rates with cosmic star formation rates using power-law distributed delay times f(τ) ∝τ-1, where a broken-power-law luminosity function is assumed and some empirical observational selection effects are taken into account. As a result, the most-likely model parameters are constrained to be ν1 = 0.91, ν2 = 1.66 as power-law indices, with a break at Lb= 2.51 × 1051 erg s-1 for the luminosity function and τc= 6.0 Gyr for a typical gravitational wave decay timescale of the binary orbit. The corresponding local rate of short GRBs is found to be 3-4 Gpc-3 yr-1. With these parameters, the detectable numbers of short GRBs are estimated within the horizon of Advanced LIGO.

关键词： gamma-ray burst:general luminosity function stars:neutron

Observational signature of a wind bubble environment for double neutron star mergers

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Research in Astronomy and Astrophysics 2019年第8期19卷 93-98页

作者： Yong-Sen Li Aming Chen yun-wei yu Institute of Astrophysics Central China Normal UniversityWuhan430079China Key Laboratory of Quark and Lepton Physics Central China Normal UniversityWuhan430079China

During the in-spiral stage of a compact binary, a wind bubble could be blown into the interstellar medium, if electromagnetic radiation due to the binary orbital motion is strong enough. Therefore, shortduration gamma-ray bursts(SGRBs) due to double neutron star mergers would in principle happen in a wind bubble environment, which can influence the propagation of the SGRB jet and consequent afterglow emission. By calculating the dynamics and synchrotron radiation of the jet-driven external shock, we reveal that an abrupt jump could appear in the afterglow light curves of SGRBs and the observational time of the jump is dependent on the viewing angle. This light curve jump provides an observational signature to constrain the radius of the wind bubble and thus the power of the electromagnetic radiation of the binary,by combining with gravitational wave detection.

关键词： gamma ray bursts:general gravitational waves

SN 1054: A pulsar-powered supernova?

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Research in Astronomy and Astrophysics 2015年第11期15卷 1823-1831页

作者： Shao-Ze Li yun-wei yu Yan Huang Institute of Astrophysics Central China Normal University

The famous ancient supernova SN 1054 could have been too bright to be explained in the “standard” radioactive-powered supernova scenario. As an alternative attempt, we demonstrate that the spin-down of the newly born Crab pulsar could provide a sufficient energy supply to make SN 1054 visible at daytime for 23 days and at night for 653 days, where a one-zone semi-analytical model is employed. Our results indicate that SN 1054 could be a “normal” cousin of magnetar-powered superluminous supernovae. Therefore, SN 1054-like supernovae could be a probe to uncover the properties of newly born neutron stars, which provide initial conditions for studies on neutron star evolutions.

关键词： scenario powered neutron gamma bright ancient luminosity attempt radioactive stars

Modeling the high-energy emission from the gamma-ray binary 1FGL J1018.6–5856

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Research in Astronomy and Astrophysics 2021年第8期21卷 46-58页

作者： A-Ming Chen Chowing Ng Jumpei Takata yun-wei yu School of physics Huazhong University of Science and TechnologyWuhan 430074China Department of Physics The University of Hong KongPokfulam RoadHong KongChina College of Physical Science and Technology Central China Normal UniversityWuhan 430079China

1FGL J1018.6–5856 is a high mass gamma-ray binary containing a compact object orbiting around a massive star with a period of 16.544 *** the compact object is a pulsar,non-thermal emissions are likely produced by electrons accelerated at the termination shock,and may also originate from the magnetosphere and the un-shocked wind of the *** this paper,we investigate the non-thermal emissions from the wind and the shock with different viewing geometries and study the multi-wavelength emissions from 1FGL J1018.6–*** present the analysis results of the Fermi/LAT using nearly 10 years of *** phase-resolved spectra indicate that the Ge V emissions comprise a rather steady component that does not vary with orbital motion and a modulated component that shows flux maximum around inferior *** ke V/Te V light curves of 1FGL J1018.6–5856 also exhibit a sharp peak around inferior conjunction,which are attributed to the boosted emission from the shock,while the broad sinusoidal modulations could be originating from the deflected shock tail at a larger *** modulations of Ge V flux are likely caused by the boosted synchrotron emission from the shock and the IC emission from the unshocked pulsar wind,while the steady component comes from the outer gap of the pulsar ***,we discuss the similarities and differences of 1FGL J1018.6–5856 with other binaries,like LS 5039.

关键词： binaries:close gamma rays:stars X-rays:binaries radiation mechanisms:non-thermal

Merging strangeon stars

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Research in Astronomy and Astrophysics 2018年第2期18卷 125-134页

作者： Xiao-yu Lai yun-wei yu En-Ping Zhou yun-Yang Li Ren-Xin Xu School of Physics and Mechanical & Electrical Engineering Hubei University of Education Xinjiang Astronomical Observatory Chinese Academy of Sciences Institute of Astrophysics Central China Normal University School of Physics Peking University Kavli Institute for Astronomy and Astrophysics Peking University

The state of supranuclear matter in compact stars remains puzzling, and it is argued that pul- sars could be strangeon stars. What would happen if binary strangeon stars merge？ This kind of merger could result in the formation of a hyper-massive strangeon star, accompanied by bursts of gravitational waves and electromagnetic radiation （and even a strangeon kilonova explained in the paper）. The tidal polarizability of binary strangeon stars is different from that of binary neutron stars, because a strangeon star is self-bound on the surface by the fundamental strong force while a neutron star by the gravity, and their equations of state are different. Our calculation shows that the tidal polarizability of merging bi- nary strangeon stars is favored by GW170817. Three kinds of kilonovae （i.e., of neutron, quark and strangeon） are discussed, and the light curve of the kilonova AT 2017gfo following GW170817 could be explained by considering the decaying strangeon nuggets and remnant star spin-down. Additionally, the energy ejected to the fireball around the nascent remnant strangeon star, being manifested as a gamma-ray burst, is calculated. It is found that, after a prompt burst, an X-ray plateau could follow in a timescale of 102 - 103 s. Certainly, the results could be tested also by further observational synergies between gravitational wave detectors （e.g., Advanced LIGO） and X-ray telescopes （e.g., the Chinese HXMT satellite and eXTP mission）, and especially if the detected gravitational wave form is checked by peculiar equations of state provided by the numerical relativistical simulation.

关键词： stars: neutron -- pulsars: general -- X-rays: stars -- gravitational waves

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

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Research in Astronomy and Astrophysics 2021年第8期21卷 167-172页

作者： Jian-He Zheng yun-wei yu Institute of Astrophysics Central China Normal UniversityWuhan 430079China Key Laboratory of Quark and Lepton Physics(Central China Normal University) Ministry of EducationWuhan 430079China

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 ***2019 bkc/ATLAS19 dqr is one of the fastest detected FOTs so far and,meanwhile,it was found to be unassociated with a host *** discoveries provide a good chance to explore the possible origins of ***,we model the light curves of SN 2019 bkc in *** 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 could be a spinning-down millisecond magnetar or a fallback accretion onto a compact *** 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.

关键词： stars:supernovae stars:individual(SN 2019bkc)

Long-term evolution and gravitational wave radiation of neutron stars with differential rotation induced by r-modes

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Research in Astronomy and Astrophysics 2009年第9期9卷 1024-1034页

作者： yun-wei yu Xiao-Feng Cao Xiao-Ping Zheng Institute of Astrophysics Huazhong Normal University Wuhan 430079 China

In a second-order r-mode theory, Sa and Tome found that the r-mode oscillation in neutron stars （NSs） could induce stellar differential rotation, which naturally leads to a saturated state of the oscillation. Based on a consideration of the coupling of the r-modes and the stellar spin and thermal evolution, we carefully investigate the influences of the differential rotation on the long-term evolution of isolated NSs and NSs in low-mass X-ray binaries, where the viscous damping of the r-modes and its resultant effects are taken into account. The numerical results show that, for both kinds of NSs, the differential rotation can significantly prolong the duration of the r-modes. As a result, the stars can keep nearly a constant temperature and constant angular velocity for over a thousand years. Moreover, the persistent radiation of a quasi-monochromatic gravitational wave would also be predicted due to the long-term steady r-mode oscillation and stellar rotation. This increases the detectability of gravitational waves from both young isolated and old accreting NSs.

关键词： stars: neutron -- stars: evolution -- stars: rotation -- gravitational waves

Merging strangeon stars Ⅱ:the ejecta and light curves

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Research in Astronomy and Astrophysics 2021年第10期21卷 86-96页

作者： Xiao-yu Lai Cheng-Jun Xia) yun-wei yu Ren-Xin Xu Department of Physics and Astronomy Hubei University of EducationWuhan 430205China Research Center for Astronomy Hubei University of EducationWuhan 430205China School of Information Science and Engineering NingboTech UniversityNingbo 315100China Institute of Astrophysics Central China Normal UniversityWuhan 430079China School of Physics Peking UniversityBeijing 100871China Kavli Institute for Astronomy and Astrophysics Peking UniversityBeijing 100871China

The state of supranuclear matter in compact stars remains puzzling,and it is argued that pulsars could be strangeon *** consequences of merging double strangeon stars are worth exploring,especially in the new era of multi-messenger *** develop the"strangeon kilonova"scenario proposed in Paper I,we make a qualitative description about the evolution of ejecta and light curves for merging double strangeon *** the hot environment of the merger,the strangeon nuggets ejected by tidal disruption and hydrodynamical squeezing would suffer from evaporation,in which process particles,such as strangeons,neutrons and protons,are *** into account both the evaporation of strangeon nuggets and the decay of strangeons,most of the strangeon nuggets would turn into neutrons and protons,within dozens of milliseconds after being *** evaporation rates of different particles depend on temperature,and we find that the ejecta could end up with two components,with high and low opacity *** high opacity component would be in the directions around the equatorial plane,and the low opacity component would be in a broad range of angular *** bolometric light curves show that the spin-down power of the long-lived remnant would account for the whole emission of kilonova AT2017gfo associated with GW170817,if the total ejected mass 10^(-3)M⊙.The detailed picture of merging double strangeon stars is expected to be tested by future numerical simulations.

关键词： dense matter equation of state pulsars:general

HLA-G expression in the peripheral blood of live kidney transplant recipients

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Chinese Medical Journal 2013年第14期126卷 2652-2655页

作者： XIAO Li ZHOU Wen-qiang SHI Bing-yi FENG Kai HE Xiu-yun wei yu-xiang GAO yu MENG Xiao-yun XIAO wei Beijing Key Laboratory of Immunology Regulatory and Organ Transplantation Basic Research Lab of Organ Transplant Institue 309th Hospital of the People's Liberation Army Beijing 100091 China

Background The human leukocyte antigen-G （HLA-G） has been considered to be an important tolerogeneic molecule playing an essential role in maternal-fetal tolerance, upregulated in the context of transplantation, malignancy, and inflammation, and has been correlated with various clinical outcomes. The aim of this study was to investigate the clinical relevance of the expression of membrane HLA-G （mHLA-G）, intracellular HLA-G （iHLA-G）, and soluble HLA-G （sHLA-G） in the peripheral blood of live kidney transplant recipients. Methods We compared the expression of the three HLA-G isoforms in three groups, healthy donors （n=20）, recipients with acute rejection （n=19）, and functioning transplants （n=30）. Flow cytometry was used to detect the expression of mHLA-G and iHLA-G in the T lymphocytes of peripheral blood from subjects in the three groups. Enzyme-linked immunosorbent assays were used to detect sHLA-G in the plasma from the three groups. Results There were no significant differences in mHLA-G and intracellular HLA-G among the three groups, but the sHLA-G plasma level was higher in the functioning group than in the acute rejection or healthy group. We found a subset of CD4＊HLA-G~ and CD8~HLA-G＋T lymphocytes with low rates of mHLA-G expression in the peripheral blood of kidney transplantation recipients. Intracellular expression of HLA-G was detected in T lymphocytes. However, there was no correlation between acute rejection and the mHLA-G or intracellular HLA-G expression. Conclusion sHLA-G was the major isoform in the peripheral blood of live kidney transplant recipients and high sHLA-G levels were associated with allograft acceptance.

关键词： HLA-G kidney transplantation