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Implications of the Stellar Mass Density of High-z Massive Galaxies from JWST on Warm Dark Matter

Research in Astronomy and Astrophysics 2024年第1期24卷 128-134页

作者： Hengjie Lin Yan Gong Bin Yue Xuelei Chen National Astronomical Observatories Chinese Academy of SciencesBeijing 100101China University of Chinese Academy of Sciences Beijing 100049China Science Center for China Space Station Telescope National Astronomical ObservatoriesChinese Academy of SciencesBeijing 100101China Department of Physics College of SciencesNortheastern UniversityShenyang 110819China Center for High Energy Physics Peking UniversityBeijing 100871China

A significant excess of the stellar mass density at high redshift has been discovered from the early data release of James Webb Space Telescope(JWST),and it may require a high star formation ***,this will lead to large number density of ionizing photons in the epoch of reionization(EoR),so that the reionization history will be changed,which can arise tension with the current EoR *** dark matter(WDM),via the free streaming effect,can suppress the formation of small-scale structure as well as low-mass *** provides an effective way to decrease the ionizing photons when considering a large star formation efficiency in high-z massive galaxies without altering the cosmic reionization *** the other hand,the constraints on the properties of WDM can be derived from the JWST *** this work,we study WDM as a possible solution to reconcile the JWST stellar mass density of high-z massive galaxies and reionization *** find that,the JWST high-z comoving cumulative stellar mass density alone has no significant preference for either CDM or WDM *** using the observational data of other stellar mass density measurements and reionization history,we obtain that the WDM particle mass with mw=0.51_(-0.12)^(+0.22) keV and star formation efficiency parameter f_(*)^(0)> 0.39 in 2σ confidence level can match both the JWST high-z comoving cumulative stellar mass density and the reionization history.

关键词： Cosmology (cosmology:)dark matter (cosmology:)large-scale structure of universe

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VLBI with SKA:Possible Arrays and Astrometric Science

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Research in Astronomy and Astrophysics 2024年第7期24卷 1-33页

作者： Yingjie Li Ye Xu Jingjing Li Shuaibo Bian Zehao Lin Chaojie Hao Dejian Liu Purple Mountain Observatory Chinese Academy of SciencesNanjing 210023China University of Science and Technology of China Hefei 230026China

The next generation of very long baseline interferometry(VLBI)is stepping into the era of microarcsecond(μas)astronomy,and pushing astronomy,especially astrometry,to new *** with the Square Kilometre Array(SKA),SKA-VLBI,will increase current sensitivity by an order of magnitude,and reach astrometric precision routinely below 10μas,even challenging 1μ*** advancement allows precise parallax and proper motion measurements of various celestial *** improvements can be used to study objects(including isolated objects,and binary or multiple systems)in different stellar stages(such as star formation,main-sequence stars,asymptotic giant branch stars,pulsars,black holes,white dwarfs,etc.),unveil the structure and evolution of complex systems(such as the Milky Way),benchmark the international celestial reference frame,and reveal cosmic ***,the theory of general relativity can also be tested with SKA-VLBI using precise measurements of light deflection under the gravitational fields of different solar system objects and the perihelion precession of solar system objects.

关键词： astrometry-parallaxes-stars kinematics and dynamics-ISM kinematics and dynamics-Galaxy kinematics and dynamics-galaxies kinematics and dynamics-gravitation

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Variable Stars in the 50BiN Open Cluster Survey.Ⅲ.NGC 884

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Research in Astronomy and Astrophysics 2024年第2期24卷 36-45页

作者： Lin-Hong Wang Qian-Heng Nie Kun Wang Xiao-Dian Chen Chun-Guang Zhang Li-Cai Deng Xiao-Bin Zhang Tian-Lu Chen Department of Physics College of ScienceTibet UniversityLhasa 850000China Key Laboratory of Cosmic Rays Tibet UniversityMinistry of EducationLhasa 850000China Key Laboratory of Optical Astronomy National Astronomical ObservatoriesChinese Academy of SciencesBeijing 100101China School of Astronomy and Space Science University of Chinese Academy of SciencesBeijing 100049China Middlesex School ConcordMassachusettsUnited States of America School of Physics and Astronomy China West Normal UniversityNanchong 637002China

Open clusters are the basic building blocks that serve as a laboratory for the study of young stellar populations in the Milky *** stars in open clusters provide a unique way to accurately probe the internal structure,temporal and dynamical evolutionary stages of individual stars and the host *** most powerful tool for such studies is time-domain photometric *** paper follows the route of our previous work,concentrating on a photometric search for variable stars in NGC *** target cluster is the companion of NGC869,forming the well-known double cluster system that is gravitationally *** the observation run in 2016 November,a total of 9247 B-band CCD images and 8218Ⅴ-band CCD images were *** detected a total of 15 stars with variability in visual brightness,including five Be stars,three eclipsing binaries,and seven of unknown *** new variable stars were discovered in this *** also compared the variable star content of NGC 884 with its companion NGC 869.

关键词： stars variables general-(Galaxy:)open clusters and associations individual(…,…)-(stars:)binaries general

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Dynamical Dark Energy in Light of Cosmic Distance Measurements.Ⅰ.A Demonstration Using Simulated Datasets

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Research in Astronomy and Astrophysics 2024年第6期24卷 7-14页

作者： Gan Gu Xiaoma Wang Xiaoyong Mu Shuo Yuan Gong-Bo Zhao National Astronomical Observatories Chinese Academy of SciencesBeijing 100101China University of Chinese Academy of Sciences Beijing 100049China Institute for Frontiers in Astronomy and Astrophysics Beijing Normal UniversityBeijing 102206China

We develop methods to extract key dark energy information from cosmic distance measurements including the BAO scales and supernova(SN) luminosity *** using simulated data sets of the complete DESI,LSST and Roman surveys designed for BAO and SN distance measurements,we show that using our method,the dynamical behavior of the energy,pressure,equation of state(with its time derivative) of dark energy and the cosmic deceleration function can all be accurately recovered from high-quality data,which allows for robust diagnostic tests for dark energy models.

关键词： (cosmology:)dark energy (cosmology:)large scale structure of universe (cosmology:)cosmic background radiation (cosmology:)cosmological parameters

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Astronomical Knowledge Entity Extraction in Astrophysics Journal Articles via Large Language Models

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Research in Astronomy and Astrophysics 2024年第6期24卷 140-155页

作者： Wujun Shao Rui Zhang Pengli Ji Dongwei Fan Yaohua Hu Xiaoran Yan Chenzhou Cui Yihan Tao Linying Mi Lang Chen National Astronomical Observatories Chinese Academy of SciencesBeijing 100101China University of Chinese Academy of Sciences Beijing 100049China National Astronomical Data Center Beijing 100101China Research Institute of Artificial Intelligence Zhejiang LabHangzhou 311100China Guilin University Guangxi 541006China Xidian University Xi’an 710126China

Astronomical knowledge entities,such as celestial object identifiers,are crucial for literature retrieval and knowledge graph construction,and other research and applications in the field of *** methods of extracting knowledge entities from texts face numerous challenging obstacles that are difficult to ***,there is a pressing need for improved methods to efficiently extract *** study explores the potential of pre-trained Large Language Models(LLMs)to perform astronomical knowledge entity extraction(KEE)task from astrophysical journal articles using *** propose a prompting strategy called PromptKEE,which includes five prompt elements,and design eight combination prompts based on *** select four representative LLMs(Llama-2-70B,GPT-3.5,GPT-4,and Claude 2)and attempt to extract the most typical astronomical knowledge entities,celestial object identifiers and telescope names,from astronomical journal articles using these eight combination *** accommodate their token limitations,we construct two data sets:the full texts and paragraph collections of 30 *** the eight prompts,we test on full texts with GPT-4and Claude 2,on paragraph collections with all *** experimental results demonstrate that pre-trained LLMs show significant potential in performing KEE tasks,but their performance varies on the two data ***,we analyze some important factors that influence the performance of LLMs in entity extraction and provide insights for future KEE tasks in astrophysical articles using ***,compared to other methods of KEE,LLMs exhibit strong competitiveness in multiple aspects.

关键词： astronomical databases:miscellaneous virtual observatory tools methods:data analysis

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Low Surface Brightness Galaxies Selected by Different Model Fitting

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Research in Astronomy and Astrophysics 2024年第1期24卷 223-236页

作者： Bing-Qing Zhang Hong Wu Wei Du Pin-Song Zhao Min He Feng-Jie Lei Key Laboratory of Optical Astronomy National Astronomical ObservatoriesChinese Academy of SciencesBeijing 100101China School of Astronomy and Space Science University of Chinese Academy of SciencesBeijing 100049China

We present a study of low surface brightness galaxies(LSBGs) selected by fitting the images for all the galaxies inα.40 SDSS DR7 sample with two kinds of single-component models and two kinds of two-component models(disk+bulge):single exponential,single sersic,exponential+deVaucular(exp+deV),and exponential+sérsic(exp+ser).Under the criteria of the B band disk central surface brightness μ_(0,disk)(B)≥22.5 mag arcsec^(-2) and the axis ratio b/a> 0.3,we selected four none-edge-on LSBG samples from each of the models which contain 1105,1038,207,and 75 galaxies,*** are 756 galaxies in common between LSBGs selected by exponential and sersic models,corresponding to 68.42% of LSBGs selected by the exponential model and 72.83% of LSBGs selected by the sersic model,the rest of the discrepancy is due to the difference in obtaining μ_(0) between the exponential and sersic *** on the fitting,in the range of 0.5≤n≤1.5,the relation of μ_(0) from two models can be written as μ_(0,sérsic)-μ_(0,exp)=-1.34(n-1).The LSBGs selected by disk+bulge models(LSBG_(2)comps) are more massive than LSBGs selected by single-component models(LSBG_1comp),and also show a larger disk *** the bulges in the majority of our LSBG_(2)comps are not prominent,more than 60% of our LSBG_(2)comps will not be selected if we adopt a single-component model *** also identified 31 giant low surface brightness galaxies(gLSBGs) from LSBG_(2)*** are located at the same region in the color-magnitude diagram as other *** we compared different criteria of gLSBGs selection,we find that for gas-rich LSBGs,M_(*)> 10^(10)M_⊙ is the best to distinguish between gLSBGs and normal LSBGs with bulge.

关键词： catalogs galaxies:spiral galaxies:bulges methods:data analysis methods:statistical

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Slip rate and interseismic coupling along the Moxi-Shimian segment of the Xianshuihe fault, Eastern Qinghai-Xizang Plateau

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Geodesy and Geodynamics 2024年第4期15卷 338-351页

作者： Xinyu Zhao Gang Liu Zhaosheng Nie Wei Xiong Wei Chen Mu Lin Dijin Wang Qi Li Jiansheng Yu Dongzhen Wang Pengfei Yu Institute of Seismology China Earthquake AdministrationWuhan 430071China Key Laboratory of Earthquake Geodesy.China Earthquake Administration Wuhan 430071China State Key Laboratory of Geodesy and Earth's Dynamics Innovation Academy for Precision Measurement Science and TechnologyChinese Academy of SciencesWuhan 430077China

On September 5,2022,the Luding M6.8 earthquake occurred in the Moxi-Shimian segment of the Xianshuihe fault,coinciding with the historical ruptured zone of the 1786 Moxi *** seis-mogenic environment provides a foundation for comprehending the mechanism of the earthquake and its future *** the Moxi-Shimian segment,we establish a series of near-field Global Navigation Satellite Systems(GNsS)stations to enhance the spatial resolution of observational data for the inversion of the interseismic kinematic *** this study,with an elastic screw dislocation model con-strained by GNsS observations,the slip rate of the Moxi-Shimian segment is estimated to be 10.9±1.0 mm/yr,while the locking depth is 15.7±6.2 ***,we utilize a block-dislocation model to invert the interseismic fault coupling along the Kangding-Moxi-Shimian *** result indicates a gradual deepening of the locking depth along the section from Kangding to *** coseismic rupture of the 2022 event occurred within the high coupling regions in the Kangding-Moxi-Shimian segment,which indicates that the rupture kinematics in this event might be controlled by the interseismic *** seismic moment accumulated within the ruptured zone of the Luding earthquake since 1786 ranges in[1.42-3.40]×10^(19) N-m,which is significantly greater than the seismic moment released during the 2022 *** a result,we infer that the Luding earthquake released only a portion of the accumulated energy within the original rupture zone since 1786,indicating that the 2022 event has not caused a complete rupture in the Moxi-Shimian ***,there remains a substantial seismic hazard in this area.

关键词： Moxi-Shimian segment of Xianshuihe fault Luding earthquake Global positioning system Interseismic kinematic parameters

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Crystal structures of RNA-dependent RNA polymerases from Jingmen tick virus and Alongshan virus

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hLife 2024年第1期2卷 18-31页

作者： Zhenyang Liu Qi Peng Pu Han Lu Kuai Jianxun Qi Yi Shi cas Key Laboratory of Pathogen Microbiology and Immunology Institute of MicrobiologyChinese Academy of SciencesBeijingChina Beijing Life Science Academy BeijingChina International Institute of Vaccine Research and Innovation Savaid Medical SchoolUniversity of Chinese Academy of SciencesBeijingChina Center for Influenza Research and Early-warning CAS-TWAS Center of Excellence for Emerging Infectious DiseaseChinese Academy of SciencesBeijingChina Research Unit of Adaptive Evolution and Control of Emerging Viruses Chinese Academy of Medical SciencesBeijingChina

Jingmenviruses are a group of flavi-like viruses with segmented genome and have been found in various types of hosts,including humans,cattle,monkeys,bats,rodents,sheep,ticks,mosquitoes and ***,including the Jingmen tick virus(JMTV)and Alongshan virus(ALSV),have been associated with febrile illness and flu-like symptoms in *** polymerase plays critical roles in genome replication and transcription and is an ideal target for antiviral ***,we determined the crystal structures of RNA-dependent RNA polymerase(RdRp)domains of JMTV and ALSV at 2.6Åand 3.2Åresolutions,*** overall structures of JMTV and ALSV RdRp domains are similar to those from the typical unsegmented viruses in Flaviviridae family,especially the Flavivirus *** and ALSV RdRps can be divided into three subdomains and the catalytical Motif A-G are conserved like the typical flaviviruses,whereas the zinc-binding pockets are absent from the JMTV and ALSV *** 50-ends of jingmenvirus genomes are varied in length and sequence,and a highly conserved 8-nucleotide element located on the tip of stem loop A was identified and shown to be required for binding with RdRp and performing de novo replication *** findings provide important structural insights into RdRp of segmented flavivirus and reveal the key region of virus genome responsible for replication initiation,which would promote molecular understanding of segmented flavivirus replication and the structure-based design of antiviral drugs against flaviviruses.

关键词： Jingmenviruses X-rays RNA-dependent RNA polymerase replication

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Observation of HⅠaround three Satellite Galaxies of M31 with FAST:AndromedaⅡ,NGC 205,and NGC 185

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Research in Astronomy and Astrophysics 2024年第8期24卷 52-59页

作者： Ziming Liu Jie Wang Yingjie Jing Chen Xu Tiantian Liang Qingze Chen Zerui Liu Zhipeng Hou Yougang Wang National Astronomical Observatories Chinese Academy of SciencesBeijing 100101China School of Astronomy and Space Science University of Chinese Academy of SciencesBeijing 100049China

With the exceptional sensitivity of the Five-hundred-meter Aperture Spherical radio Telescope,we conducted observations of the neutral hydrogen(HⅠ)in the circumgalactic medium of Andromeda’s(M31)satellite galaxies,specifically AndromedaⅡ,NGC 205,and NGC ***,three drift scans were executed for these satellites,with a detection limit of 4×10^(18)cm^(-2)(approximately 1.88×10^(3)M_Θof HⅠmass),followed by a more in-depth scan of a specific *** discovered a C-shaped HⅠarc structure sharing a position and line-of-sight velocity similar to a stellar ring structure around AndromedaⅡ,hinting at a potential connection with AndromedaⅡ.In the context of NGC 205,we identified two mass concentrations in the northeast direction,which could be indicative of tidal streams resulting from the interaction between this galaxy and *** new lumps discovered could be very helpful in solving the missing interstellar medium problem for NGC *** regarding NGC 185are consistent with previous studies,and we did not detect any additional HⅠmaterial around this *** observational results enhance our understanding of the evolution of these satellite galaxies and provide insight into their historical interactions with the galaxy M31.

关键词： ISM structure-(Galaxy)local interstellar matter-galaxies interactions-galaxies ISM-(galaxies)Local Group-radio lines ISM-radio lines galaxies

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All-sky Guide Star Catalog for CSST

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Research in Astronomy and Astrophysics 2024年第4期24卷 35-59页

作者： Hui-Mei Feng Zi-Huang Cao Man I Lam Ran Li Hao Tian Da-Yi Yin Yuan-Yu Yang Xin Zhang Dong-Wei Fan Yi-Qiao Dong Xin-Feng Li Wei Wang Long Li Hugh RAJones Yi-Han Tao Jia-Lu Nie Pei-Pei Wang Mao-Yuan Liu He-jun Yang Chao Liu Key Laboratory of Cosmic Rays(Tibet University) Ministry of EducationLhasa 850000China Institute for Frontiers in Astronomy and Astrophysics Beijing Normal UniversityBeijing 102206China National Astronomical Observatories Chinese Academy of SciencesBeijing 100101China University of ChineseAcademy of Sciences Beijing 100049China Shanghai Institute of Technical Physics Chinese Academy of SciencesShanghai200083China Technology and Engineering Center for Space Utilization.Chinese Academy of Sciences Beijing 100094China Changchun Institute of Optics Fine Mechanics and PhysicsChinese Academy of SciencesChangchun 130033China Centre for Astrophysics University of HertfordshireHatfieldUK Beijing University of Technology Beijing 100124China

The China Space Station Telescope(CSST)is a two-meter space telescope with multiple back-end *** Fine Guidance Sensor(FGS)is an essential subsystem of the CSST Precision Image Stability System to ensure the required absolute pointing accuracy and line-of-sight *** this study,we construct the Main Guide Star Catalog for *** accomplish this,we utilize the information about the FGS and object information from the Gaia Data Release *** provide an FGS instrument magnitude and exclude variables,binaries,and high proper motion stars from the catalog to ensure uniform FGS guidance ***,we generate a HEALPix index,which provides a hierarchical tessellation of the celestial sphere,and employ the Voronoi algorithm to achieve a homogeneous distribution of stars across the *** distribution ensures adequate coverage and sampling of the *** performance of the CSST guide star catalog was assessed by simulating the field of view of the FGS according to the CSST mock survey strategy *** analysis of the results indicates that this catalog provides adequate coverage and *** catalog's performance meets the FGS requirements,ensuring the functioning of the FGS and its guidance capabilities.

关键词： catalogs astrometry instrumentation:detectors

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