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Quenched Galaxies are Important Host Candidates of Binary Black Hole and Binary Neutron Star Mergers

Research in Astronomy and Astrophysics 2023年第9期23卷 29-44页

作者： Xiaobo Gong Feng-Hui Zhang Xiaoyu Kang Lifang Li Yunnan Observatories Chinese Academy of SciencesKunming 650216China Key Laboratory for the Structure and Evolution of Celestial Objects Chinese Academy of SciencesKunming 650216China University of Chinese Academy of Sciences Beijing 100049China International Centre of Supernovae Yunnan Key LaboratoryKunming 650216China

In this work,we present the probabilities of mergers of binary black holes(BBHs)and binary neutron stars(BNSs)as functions of stellar mass,metallicity,specific star formation rate(sSFR),and age for galaxies with redshift z≤*** the binary-star evolution(BSE)code and some fitting formulae,we construct a phenomenological model of cosmic gravitational wave(GW)merger *** using the Bayesian analysis method and the observations from Advanced LIGO and Virgo,we obtain the relevant parameters of the phenomenological model(such as the maximum black hole mass is 93_(-22)^(+73)M_(⊙)).Combining the above model results with the galaxy catalog given by the EMERGE empirical galaxy model,we find the normalized probability of occurrence of a merger event varying with log10 sSFR yr(-1)for galaxies with z≤0.1 is different from that in previous studies,that is,two peaks exist in this work while there is only one peak(log_(10)(sSFR/yr^(−1))=−10)in the previous *** sSFR value corresponding to the new peak is log_(10)(sSFR/yr^(−1))=−12 and in line with the value(log_(10)(sSFR yr^-1)=-12.65_(-0.66)^(+0.44)of NGC 4493,the host galaxy of BNS merger event *** new peak is caused by today’s quenched galaxies,which give a large contribution to the total SFR at high redshift in the EMERGE empirical galaxy ***,we find that the BNS mergers are most likely detected in galaxies with age∼11 Gyr,which is greater than previous results(6−8Gyr)and close to the age of NGC 4993,13.2_(-0.9)^(+0.5)Gyr.

关键词： stars black holes–stars massive–gravitational waves–galaxies evolution

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Decametric Solar Radio Spectrometer Based on 4-element Beamforming Array and Initial Observational Results

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Research in Astronomy and Astrophysics 2023年第8期23卷 82-91页

作者： Shao-Jie Guo Guan-Nan Gao Fa-Xin Shen Feng-Hui Yang Liang Dong Min Wang Yunnan Observatories Chinese Academy of SciencesKunming 650216China University of Chinese Academy of Sciences Beijing 100049China Yunnan Key Laboratory of the Solar Physics and Space Science Kunming 650216China Key Laboratory for the Structure and Evolution of Celestial Objects Chinese Academy of SciencesKunming 650216China

The dynamic spectral observation at decametric wavelength is important to study solar radio physics and space ***,the observing system is difficult to observe with high sensitivity at this band due to the fact that the system temperature is dominated by the sky background noise and the antenna is difficult to design with high *** effective solution to improve the sensitivity is constructing an antenna array based on the beamforming ***,we develop a decametric solar radio spectrometer system based on a 4-element beamforming *** system consists of four antennas,an 8-channel analog receiver and a digital *** use the true time delay to implement the beamformer and the classical FFT method to perform spectrum analysis in the digital *** at a frequency range of 25–65 MHz with dual-circular polarizations,the system provides high resolution dynamic spectrum with spectral resolution of~12 kHz and temporal resolution of~5.3 ms(typical).Tens of solar radio bursts have been observed successfully during the period of the trial observation,demonstrating the system's ability to detect fine structures with high spectral and temporal *** this article,we present the design,implementation,and initial observational results of the decametric solar radio spectrometer system in detail.

关键词： instrumentation spectrographs-methods observational-Sun radio radiation-radiation dynamics

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Correcting the Contamination of Second-order Spectra:Improving HαMeasurements in Reverberation Mapping Campaigns

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Research in Astronomy and Astrophysics 2023年第12期23卷 242-251页

作者： Wen-Zhe Xi Kai-Xing Lu Hai-Cheng Feng Sha-Sha Li Jin-Ming Bai Rui-Lei Zhou Hong-Tao Liu Jian-Guo Wang Yunnan Observatories Chinese Academy of SciencesKunming 650011China University of Chinese Academy of Sciences Beijing 100049China Key Laboratory for the Structure and Evolution of Celestial Objects Chinese Academy of SciencesKunming 650011China CAS Key Laboratory of FAST National FASTNational Astronomical ObservatoriesChinese Academy of SciencesBeijing 100101China

Long-term spectroscopic monitoring campaigns on active galactic nuclei(AGNs)provide a wealth of information about its interior structure and ***,a number of the observations suffer from the contamination of second-order spectra(SOS)which will introduce some undesirable uncertainties at the red side of the *** this paper,we test the effect of SOS and propose a method to correct it in the time domain spectroscopic data using the simultaneously observed comparison *** on the reverberation mapping(RM)data of NGC 5548 in2019,one of the most intensively monitored AGNs by the Lijiang 2.4 m telescope,we find that the scientific object,comparison star,and spectrophotometric standard star can jointly introduce up to~30%SOS for Grism *** irregular but smooth SOS significantly affects the flux density and profile of the emission line,while having little effect on the light *** applying our method to each spectrum,we find that the SOS can be corrected *** deviation between corrected and intrinsic spectra is~2%,and the impact of SOS on time lag is very *** method makes it possible to obtain the HαRM measurements from archival data provided that the spectral shape of the AGN under investigation does not have a large change.

关键词： techniques spectroscopic-methods data analysis-galaxies individual(NGC 5548)-(galaxies:)quasars emission lines

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Machine Learning to Search for Accreting Neutron Star Binary Candidates Using Chinese Space Station Telescope Photometric System

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Research in Astronomy and Astrophysics 2022年第12期22卷 322-334页

作者： Shun-Yi Lan Kai-Fan Ji Xiang-Cun Meng Yunnan Observatories Chinese Academy of SciencesKunming 650216China Key Laboratory for the Structure and Evolution of Celestial Objects Chinese Academy of SciencesKunming 650216China University of Chinese Academy of Sciences Beijing 100049China

Accreting neutron star binary(ANSB)systems can provide some important information about neutron stars(NSs),especially on the structure and the equation of state of ***,only a few ANSBs are known so *** upcoming Chinese Space Station Telescope(CSST)provides an opportunity to search for a large number of ANSB *** aim to investigate whether or not a machine learning method may efficiently search for ANSBs based on CSST photometric *** this paper,we generate some ANSBs and normal binaries under CSST photometric system by binary evolution and binary population synthesis method and use a machine learning method to train a classification *** consider the classical multi-color disk and the irradiated accretion disk,then compare their effects on the classification *** find that no matter whether the X-ray reprocessing effect is included or not,the machine learning classification accuracy is always very high,i.e.,higher than 96%.If a significant magnitude difference exists between the accretion disk and the companion of an ANSB,machine learning may not distinguish it from some normal stars such as massive main sequence stars,white dwarf binaries,*** classifications of the ANSBs and the normal stars highly overlap in a color–color *** results indicate that machine learning would be a powerful way to search for potential ANSB candidates from the CSST survey.

关键词： stars:neutron X-rays:binaries methods:analytical

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The Origin of The Soft X-Ray Excess in the Seyfert 1.5 Galaxy ESO 362-G18

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Research in Astronomy and Astrophysics 2022年第3期22卷 10-32页

作者： Xiao-Gu Zhong Jian-Cheng Wang Yunnan Observatories Chinese Academy of SciencesKunming 650216China Key Laboratory for the Structure and Evolution of Celestial Objects Chinese Academy of SciencesKunming 650216China University of Chinese Academy of Sciences Beijing 100049China

We review the Seyfert 1.5 Galaxy ESO 362-G18 for exploring the origin of the soft X-ray *** Warm Corona and Relativistic Reflection models are two main scenarios to interpret the soft X-ray excess in active galactic nuclei at *** use the simultaneous X-ray observation data of XMM-Newton and Nu STAR on2016 September 24 to perform spectral analysis in two ***,we analyze the time-average spectra by using Warm Corona and Relativistic Reflection ***,we also explore the Hybrid model,Double Reflection model and Double Warm Corona *** find that both the Warm Corona and Relativistic Reflection models can interpret the time-average spectra well but cannot be distinguished easily based on the time-averaged spectra fit ***,we add the rms and covariance spectra to perform the spectral analysis with time-average *** result shows that the warm corona could reproduce all of these spectra *** hot,optical thin corona and neutral distant reflection will increase their contribution with the temporal frequency,meaning that the corona responsible for X-ray continuum comes from the inner compact X-ray region and the neutral distant reflection is made of some moderate scale neutral clumps.

关键词： galaxies:active galaxies:individual(ESO 362-G18) galaxies:Seyfert

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An Exposure Meter of Lijiang Fiber-fed High-Resolution Spectrograph

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Research in Astronomy and Astrophysics 2023年第11期23卷 60-66页

作者： Xiao-Guang Yu Kai-Fan Ji Xi-Liang Zhang Liang Chang Yun-Fang Cai Ying Qin Zhen-Hong Shang Yunnan Observatories Chinese Academy of SciencesKunming 650011China Key Laboratory for the Structure and Evolution of Celestial Objects Chinese Academy of SciencesKunming 650216China University of Chinese Academy of Sciences Beijing 100049China Faculty of Information Engineering and Automation Kunming University of Science and TechnologyKunming 650500China

In 2016,an exposure meter was installed on the Lijiang Fiber-fed High-Resolution Spectrograph to monitor the coupling of starlight to the science fiber during *** on it,we investigated a method to estimate the exposure flux of the CCD in real time by using the counts of the photomultiplier tubes(PMT)of the exposure meter,and developed a piece of software to optimize the control of the exposure ***,by using flat-field lamp observations,we determined that there is a linear and proportional relationship between the total counts of the PMT and the exposure flux of the ***,using historical observations of different spectral types,the corresponding relational conversion factors were determined and obtained ***,the method was validated using actual observation data,which showed that all values of the coefficient of determination were greater than ***,software was developed to display the counts of the PMT and the estimated exposure flux of the CCD in real-time during the observation,providing a visual reference for optimizing the exposure time control.

关键词： telescopes instrumentation:spectrographs instrumentation:photometers

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Locating multiple roots of nonlinear equation systems via multi-strategy optimization algorithm with sequence quadratic program

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Science China(Information Sciences) 2022年第7期65卷 248-250页

作者： Jing LIANG Boyang QU Baolei LI Kunjie YU Caitong YUE School of Electrical Engineering Zhengzhou University School of Electronic and Information Engineering Zhongyuan University of Technology School of Physics and Electronic Engineering Nanyang Normal University Key Laboratory for the Structure and Evolution of Celestial Objects Chinese Academy of Sciences

Dear editor, Locating all the roots of a nonlinear equation system (NES) is not only of great significance for solving real-world problems but also one of the core problems of mathematics [1]. A NES can be defined by

关键词： multi-strategy optimization algorithm sequence quadratic program nonlinear equation system multimodal optimization multiple swarms optimization algorithm

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Detection of Gamma-Rays from the Protostellar Jet in the HH 80–81 System

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Research in Astronomy and Astrophysics 2022年第2期22卷 183-188页

作者： Da-Hai Yan Jia-Neng Zhou Peng-Fei Zhang Key Laboratory for the Structure and Evolution of Celestial Objects Yunnan ObservatoriesChinese Academy of SciencesKunming 650011China Shanghai Astronomical Observatory Chinese Academy of SciencesShanghai 200030China Department of Astronomy Key Laboratory of Astroparticle Physics of Yunnan ProvinceYunnan UniversityKunming 650091China

Considering that the existence of relativistic particles in the protostellar jet has been confirmed by the detection of linearly polarized radio emission from the HH 80–81 jet,we search for gamma-rays from the HH 80–81 system using ten-year Fermi-LAT observations.A significant point-likeγ-ray excess is found in the direction of the HH80–81 system with the Test-Statistic value>100,which is likely produced in the HH 80–81 ***γ-ray spectrum extends only to 1 Ge V with a photon index of *** significant variability is found in the gamma-ray *** is discussed that the properties of HH 80–81 jet suffice for producing the observedγ-rays.

关键词： gamma-rays:ISM-ISM:jets and outflows radiation mechanisms:non-thermal stars:protostars

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Transient Phenomena from Gas Erupting Neutron Stars

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Research in Astronomy and Astrophysics 2022年第1期22卷 189-191页

作者： Hui-Quan Li Jian-Cheng Wang Yunnan Observatories Chinese Academy of Sciences650216 KunmingChina Key Laboratory for the Structure and Evolution of Celestial Objects Chinese Academy of Sciences650216 KunmingChina Center for Astronomical Mega-Science Chinese Academy of Sciences100012 BeijingChina

Starquakes probably occur in rapidly spinning or ultra high field neutron stars. In this article, we argue that highly compressed gas containing electron–positron pairs could evaporate and erupt from inside the neutron star when a crack forms and then heals during a starquake. Under the influence of the existing oscillation modes of the star, the crack may have sufficiently large size and long lifetime. An appropriate amount of gas can erupt into the magnetosphere with relativistic and nearly uniform velocity, producing various transient and bursting phenomena.

关键词： stars:neutron stars:magnetars (stars:)pulsars:general

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Asteroseismology of 16 Kepler Solar-like Stars:Stellar Parameters and the Effects of Element Diffusion

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Research in Astronomy and Astrophysics 2023年第7期23卷 206-220页

作者： Shuai Wang Qian-Sheng Zhang Yunnan Observatories Chinese Academy of Sciences396 YangfangwangGuandu DistrictKunming 650216China University of Chinese Academy of Sciences Beijing 100049China Center for Astronomical Mega-Science Chinese Academy of SciencesBeijing 100101China Key Laboratory for the Structure and Evolution of Celestial Objects Chinese Academy of SciencesKunming 650216China International Centre of Supernovae Yunnan Key LaboratoryKunming 650216China

Element diffusion has small but significant effects on the structure of the stellar *** is interesting to investigate the effects of element diffusion using *** have constructed two grids of stellar models,one with diffusion and one without,for solar-like stars with masses between 0.9 and 1.4 solar masses,and varied initial helium abundance and *** oscillation frequencies of all stellar models have also been *** Hermite cubic polynomials are adopted to interpolate stellar p-mode frequencies at an arbitrary age on a stellar evolutionary *** have investigated 16 Kepler solar-like stars by comparing the model frequencies with *** suggested ranges of stellar parameters and some global variables are *** all stars,the best model reproduces the observational frequencies with aχ^(2)of the order of *** has been found that element diffusion is important in modeling solar-like *** diffusion,the best value of the initial helium abundance is below the primordial helium abundance from Big Bang *** diffusion is taken into account,the required initial helium abundance increases to be higher than the primordial *** also generally improves the frequency fitting results by reducing the minimum ofχ^(2).Investigation of the second difference of the oscillation frequencies on KIC 8694723 and KIC 10454113 indicates that the current model of element diffusion may underestimate the strength of settling.

关键词： asteroseismology diffusion stars:interiors stars:abundances

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