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Chinese Physics B 2024年第4期33卷 129-134页

作者：张雅芃姚嘉文刘正东马作霖仲佳勇 department of astronomy Beijing Normal UniversityBeijing 100875China Institute for Frontiers in astronomy and astrophysics Beijing Normal UniversityBeijing 102206China

Magnetic reconnection of the self-generated magnetic fields in laser-plasma interaction is an important laboratory method for modeling high-energy density astronomical and astrophysical *** use the Martin-Puplett interferometer(MPI)polarimeter to probe the peripheral magnetic fields generated in the common magnetic reconnection configuration,two separated coplanar plane targets,in laser-target *** introduce a new method that can obtain polarization information from the interference pattern instead of the sinusoidal function fitting of the intensity.A bidirectional magnetic field is observed from the side view,which is consistent with the magneto-hydro-dynamical(MHD)simulation results of self-generated magnetic field *** find that the cancellation of reverse magnetic fields after averaging and integration along the observing direction could reduce the magnetic field strength by one to two orders of *** indicates that imaging resolution can significantly affect the accuracy of measured magnetic field strength.

关键词： laser-plasma experiment polarimeter self-generated magnetic field magnetic reconnection

Cosmological constraints from the joint analysis of clustering and lensing with the DESI Legacy Imaging Surveys

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Science China(Physics,Mechanics & astronomy) 2024年第3期67卷 169-170页

作者： Surhud More Inter-University Centre for astronomy and astrophysics Pune 411007India

The comparison between the amplitude of density fluctuations in matter today as inferred from the observations of the Cosmic Microwave background by the Planck collaboration [1] to that from the observations of the late Universe,is a stringent test of the concordance cosmological model. A joint analysis of the clustering of galaxies and their galaxygalaxy lensing signal is a unique way to constrain cosmological parameters.

关键词： galaxy parameters. galaxies

Probing turbulence in galaxies with fast radio burst scintillation

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Science China(Physics,Mechanics & astronomy) 2024年第1期67卷 177-178页

作者： James M.Cordes department of astronomy the Cornell Center for Astrophysics and Planetary ScienceCornell UniversityIthaca NY 14853USA

Interstellar scintillation(ISS)is a well-known phenomenon observed from pulsars in the Milky *** comprises intensity variations *** and frequency caused by constructive and destructive interference from multipath propagation,which is due to diffraction from fluctuations in electron density in the interstellar medium(ISM)on scales as small as~100 *** density fluctuations appear to be part of a turbulence process combined with discrete structures in electron density from other astrophysical processes;together these fluctuations extend to scales of pc or larger.

关键词： scales galaxies turbulence

Scintillation Arc from FRB 20220912A

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Science China(Physics,Mechanics & astronomy) 2024年第1期67卷 134-142页

作者： Zi-Wei Wu Robert AMain Wei-Wei Zhu Bing Zhang Peng Jiang Jia-Rui Niu Jin-Lin Han Di Li Ke-Jia Lee Dong-Zi Li Yuan-Pei Yang Fa-Yin Wang Rui Luo Pei Wang Chen-Hui Niu Heng Xu Bo-Jun Wang Wei-Yang Wang Yong-Kun Zhang Yi Feng De-Jiang Zhou Yong-Hua Xu Can-Min Deng Yu-Hao Zhu National Astronomical Observatories Chinese Academy of SciencesBeijing 100101China Max-Planck-Institut für Radioastronomie Bonn 53121Germany Institute for Frontier in astronomy and astrophysics Beijing Normal UniversityBeijing 102206China Nevada Center for astrophysics and department of Physics and astronomy University of NevadaLas VegasNV 89154USA CAS Key Laboratory of FAST National Astronomical ObservatoriesChinese Academy of SciencesBeijing 100101China School of astronomy University of Chinese Academy of SciencesBeijing 100049China NAOC-UKZN Computational astrophysics Centre University of KwaZulu-NatalDurban 4000South Africa department of astronomy Peking UniversityBeijing 100871China Kavli Institute for astronomy and astrophysics Peking UniversityBeijing 100871China Cahill Center for astronomy and astrophysics California Institute of TechnologyPasadena 91125USA South-Western Institute For astronomy Research Yunnan UniversityKunming 650504China School of astronomy and Space Science Nanjing UniversityNanjing 210093China Key Laboratory of Modern astronomy and astrophysics(Nanjing University) Ministry of EducationNanjing 210023China CSIRO Space and astronomy Epping 1710Australia department of astronomy School of Physics and Materials ScienceGuangzhou UniversityGuangzhou 510006China Research Center for Intelligent Computing Platforms Zhejiang LaboratoryHangzhou 311100China Yunnan Observatories Chinese Academy of SciencesKunming 650011China Guangxi Key Laboratory for Relativistic astrophysics Department of PhysicsGuangxi UniversityNanning 530004China

We present the interstellar scintillation analysis of fast radio burst(FRB)20220912A during its extremely active episode in 2022using data from the Five-hundred-meter Aperture Spherical Radio Telescope(FAST).We detect a scintillation arc in the FRB’s secondary spectrum,which describes the power in terms of the scattered FRB signals’time delay and Doppler *** arc indicates that the scintillation is caused by a highly localized *** analysis favors a Milky Way origin of the ionized interstellar medium(IISM)for the localized scattering medium but cannot rule out a host galaxy *** present our method for detecting the scintillation arc,which can be applied generally to sources with irregularly spaced bursts or *** methods could help shed light on the complex interstellar environment surrounding the FRBs and in our Galaxy.

关键词： fast radio burst scintillation FRB 20220912A

Pulsar Glitch Activities:The Spin Parameters Approach

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Research in astronomy and astrophysics 2024年第6期24卷 334-357页

作者： Innocent Okwudili Eya Evaristus Uzochukwu Iyida Physics/Electronics Technique—department of Science Laboratory Technology University of NigeriaNsukkaNigeria department of Physics and astronomy University of NigeriaNsukkaNigeria astronomy and astrophysics Research Lab University of NigeriaNsukkaNigeria

Glitch activity refers to the mean increase in pulsar spin frequency per year due to rotational *** is an important tool for studying super-nuclear matter using neutron star interiors as *** events are typically observed in the spin frequency(ν) and frequency derivative( ν) of *** rate of glitch recurrence decreases as the pulsar ages,and the activity parameter is usually measured by linear regression of cumulative glitches over a given *** method is effective for pulsars with multiple regular glitch ***,due to the scarcity of glitch events and the difficulty of monitoring all known pulsars,only a few have multiple records of glitch *** limits the use of the activity parameter in studying neutron star interiors with multiple *** this study,we examined the relationship between the activity parameters and pulsar spin parameters(spin frequency,frequency derivative,and pulsar characteristic age).We found that a quadratic function provides a better fit for the relationship between activity parameters and spin parameters than the commonly used linear *** this information,we were able to estimate the activity parameters of other pulsars that do not have records of *** analysis shows that the relationship between the estimated activity parameters and pulsar spin parameters is consistent with that of the observed activity parameters in the ensemble of pulsars.

关键词： stars:neutron (stars:)pulsars:general methods:statistical

Microlensing bias on the detection of strong lensing gravitational wave

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Science China(Physics,Mechanics & astronomy) 2024年第6期67卷 156-165页

作者： Xikai Shan Xuechun Chen Bin Hu Guoliang Li Institute for Frontier in astronomy and astrophysics Beijing Normal UniversityBeijing 102206China department of astronomy Beijing Normal UniversityBeijing 100875China Purple Mountain Observatory Chinese Academy of SciencesNanjing 210023China

Identifying strong lensing gravitational wave(SLGW)events is of utmost importance in astrophysics as we approach the historic first detection of SLGW amidst the growing number of gravitational wave(GW)***,one crucial method for identifying SLGW signals involves assessing the overlap of parameters between two ***,the distribution of discrete matter,such as stars and sub-halos,within the strong lensing galaxy can imprint a wave optical(WO)effect on the SLGW *** frequency dependent imprints introduce biases in parameter estimation and impact SLGW *** this study,we assess the influence of the stellar microlensing field embedded in a strong lensing *** findings demonstrate that the WO effect reduces the detection efficiency of SLGW by 5%-50%for various false alarm probabilities per pair(FAPper pair).Specifically,at an FAPper pairof 10^(-5),the detection efficiency decreases from~10%to~5%.Consequently,the presence of the microlensing field can result in missing half of the strong lensing ***,the microlensing WO effect introduces a noticeable bias in intrinsic parameters,particularly for chirp mass and mass ***,it has tiny influence on extrinsic *** all parameters,~30%of events exhibit a 1σparameter bias,~12%exhibit a 2σparameter bias,and~5%exhibit a 3σparameter bias.

关键词： gravitational wave gravitational strong lensing gravitational micro lensing wave optical effect

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Summary of a Life in Observational Ultraviolet/Optical astronomy

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Research in astronomy and astrophysics 2024年第1期24卷 1-43页

作者： Donald G.York department of astronomy and astrophysics The University of Chicago5801 South Ellis Ave.Chicago 60637ILUSA

I reminisce on my early life in Section 1;on my education in Sections 2 and 3;on the years at Princeton as a research astronomer in Section 4;on the years on the faculty at Chicago in Section 5;on research on Diffuse Interstellar Bands(DIBs) in Section 6;on construction of the 3.5 m telescope at Apache Point Observatory(APO)in Section 7;on work on the Sloan Digital Sky Survey(SDSS) in Section 8;on work in public education in Chicago in Section 9;and on my travels in Section 10. My main science research is of an observational nature,concerning Galactic and intergalactic interstellar gas. Highlights for me included my work on the orbiting telescope Copernicus, including the discovery of interstellar deuterium;early observations of absorption associated with fivetimes ionized oxygen;and discoveries concerning the phases of gas in the local interstellar medium, based on previously unobservable interstellar UV spectral lines. With other instruments and collaborations, I extended interstellar UV studies to the intergalactic cool gas using quasi-stellar object QSO absorption lines redshifted to the optical part of the spectrum;provided a better definition of the emission and morphological character of the source of absorption lines in QSO spectra;and pursued the identification of the unidentified DIBs. For several of these topics, extensive collaborations with many scientists were essential over many years. The conclusions developed slowly, as I moved from being a graduate student at Chicago, to a research scientist position at Princeton and then to a faculty position at Chicago. At each stage of life, I was exposed to new technologies adaptable to my science and to subsequent projects. From high school days, I encountered several management opportunities which were formative. I have been extremely fortunate both in scientific mentors I had and in experimental opportunities I encountered.

关键词： Interstellar Medium(ISM) Nebulae (galaxies:)quasars:absorption lines ultraviolet:stars

Probing the Kinematic Signatures of Planet Formation in the Gas Disk of MWC 480

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Research in astronomy and astrophysics 2024年第6期24卷 110-118页

作者： Min Zhao Haochuan Yu Zhengxiang Li department of astronomy Beijing Normal UniversityBeijing 100875China Sub-department of astrophysics Department of PhysicsUniversity of OxfordOxfordOX13RHUK

The disk around MWC 480 has shown multiple substructures in both dust and gas observations,possibly suggesting ongoing planet formation in *** this paper,we explore the gas kinematics of the MWC 480 disk by analyzing the archival Atacama Large Millimeter/submillimeter Array observations of^(12)CO(J=2-1),^(13)CO(J=2-1),and C^(18)O(J=2-1).By modeling the line-of-sight velocities,inferred from the Doppler shifts of the emission lines,we are able to decompose the three-dimensional(3D)velocity field of the disk into rotational,radial,and vertical *** analysis reveals the presence of large-scale gas flows in the(r,z)***,we identify potential meridional flows across various heights as traced by all three CO isotopologues in the 80–120 au region,possibly associated with ongoing planet formation activities in this ***,we find upward flows near 200 au for all three CO isotopologues,which may point to the presence of disk winds.

关键词： protoplanetary disks planet-disk interactions planet-star interactions

Detecting short-term gravitational waves from post-merger hyper-massive neutron stars with a kilohertz detector

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Chinese Physics B 2024年第8期33卷 222-228页

作者：陈奕康朱宗宏 Institute for Frontier in astronomy and astrophysics Beijing Normal UniversityBeijing 102206China department of astronomy Beijing Normal UniversityBeijing 100875China

Gravitational waves emanating from binary neutron star inspirals,alongside electromagnetic transients resulting from the aftermath of the GW170817 merger,have been successfully ***,the intricate post-merger dynamics that bridge these two sets of observables remain *** includes if,and when,the post-merger remnant star collapses to a black hole,and what are the necessary conditions to power a short gamma-ray burst,and other observed electromagnetic *** focus is on the detection of gravitational wave(GW)emissions from hyper-massive neutron stars(NSs)formed through binary neutron star(BNS)*** several kilohertz GW detectors,we simulate BNS mergers within the detection limits of LIGO-Virgo-KARGA *** objective is to ascertain the fraction of simulated sources that may emit detectable post-merger GW *** kilohertz detectors equipped with a new cavity design,we estimate that approximately 1.1%-32%of sources would emit a detectable post-merger GW *** fraction is contingent on the mass converted into gravitational wave energy,ranging from 0.01M_(sun)to 0.1M_(sun).Furthermore,by evaluating other well-regarded proposed kilohertz GW detectors,we anticipate that the fraction can increase to as much as 2.1%-61%under optimal performance conditions.

关键词： neutron star mergers gravitational waves

Toward a Direct Measurement of the Cosmic Acceleration: The Pilot Observation of HI 21 cm Absorption Line at FAST

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Research in astronomy and astrophysics 2024年第7期24卷 50-58页

作者： Jiangang Kang Chang-Zhi Lu Tong-Jie Zhang Ming Zhu Institute for Frontiers in astronomy and astrophysics Beijing Normal University School of Physics and astronomy Beijing Normal University National Astronomical Observatories Chinese Academy of Sciences

This study presents results on detecting neutral atomic hydrogen（H I） 21 cm absorption in the spectrum of PKS PKS1413+13 at redshift z = 0.24670041. The observation was conducted by FAST, with a spectral resolution of10 Hz, using 10 minutes of observing time. The global spectral profile is examined by modeling the absorption line using a single Gaussian function with a resolution of 10 kHz within a 2 MHz bandwidth. The goal is to determine the rate of the latest cosmic acceleration by directly measuring the redshift evolution of the H I 21 cm absorption line with Hubble flow toward a common background quasar over a decade or longer time span. This will serve as a detectable signal generated by the accelerated expansion of the Universe at redshift z < 1, referred to as redshift drift z（5） or the SL effect. The measured H I gas column density in this DLA system is approximately equivalent to the initial observation value, considering uncertainties of the spin temperature of a spiral host galaxy. The high signal-to-noise ratio of 57,obtained at a 10 kHz resolution, strongly supports the feasibility of using the H I 21 cm absorption line in DLA systems to accurately measure the redshift drift rate at a precision level of around 10-10per decade.

关键词： (cosmology:) cosmological parameters (cosmology:) dark energy cosmology: observations cosmology: theory ISM: clouds radio lines: galaxies radio lines: ISM