Chinese Astronomy and Astrophysics最新文献

英文中文

Observations of Ion Cyclotron Waves Upstream from the Martian Bow Shock

Q4 Physics and Astronomy

Chinese Astronomy and Astrophysics

Pub Date : 2025-01-01 DOI: 10.1016/j.chinastron.2025.03.007

Li Jia-wei , Yang Lei , Wu De-jin , Dai Cun-li , Li Jian-ping , Xiang Liang , Luo Qing-yu , Cheng Zheng-wei

Ion cyclotron waves are widely present upstream from the Martian bow shock, with frequencies near the local proton cyclotron frequency in the spacecraft frame. The waves propagate quasi-parallel to the background magnetic field, and are associated with the solar wind picking up newly-ionized hydrogen from the Martian exosphere. In this work, a typical ion cyclotron wave event was observed by MAVEN (Mars Atmosphere and Volatile Evolution) probe upstream from the Martian bow shock. The further MVA (minimum variance analysis) results for this event show that the magnetic field perturbations are left-handed polarized and propagate quasi-parallel (the propagation angle

θ

= 12.37

^{\circ}

) to the background magnetic field. The relationship between the plasma perturbations and magnetic field perturbations is theoretically derived for slow magnetosonic, Alfv{'e}n, and fast magnetosonic waves based on the magnetohydrodynamic theory. If we take the wave propagation angle

θ

= 12.37

^{\circ}

estimated from the MVA method, the theoretically expected density perturbation and velocity perturbation along the background magnetic field are in serious disagreement with the MAVEN data. Through fitting the plasma density perturbation, velocity perturbation, and magnetic field perturbation, it is found that the ion cyclotron wave event can be explained by the superposition of oblique fast magnetosonic waves with a propagation angle of 63

^{\circ}

relative to the background magnetic field and parallel propagating Alfv{'e}n waves. The results are helpful to further understand the physical nature of the observed ion cyclotron wave-related perturbations upstream from the Martian bow shock, and have guiding implications for the re-modeling and numerical simulation of the plasma physical processes therein.

{"title":"Observations of Ion Cyclotron Waves Upstream from the Martian Bow Shock","authors":"Li Jia-wei , Yang Lei , Wu De-jin , Dai Cun-li , Li Jian-ping , Xiang Liang , Luo Qing-yu , Cheng Zheng-wei","doi":"10.1016/j.chinastron.2025.03.007","DOIUrl":"10.1016/j.chinastron.2025.03.007","url":null,"abstract":"<div><div>Ion cyclotron waves are widely present upstream from the Martian bow shock, with frequencies near the local proton cyclotron frequency in the spacecraft frame. The waves propagate quasi-parallel to the background magnetic field, and are associated with the solar wind picking up newly-ionized hydrogen from the Martian exosphere. In this work, a typical ion cyclotron wave event was observed by MAVEN (Mars Atmosphere and Volatile Evolution) probe upstream from the Martian bow shock. The further MVA (minimum variance analysis) results for this event show that the magnetic field perturbations are left-handed polarized and propagate quasi-parallel (the propagation angle <span><math><mi>θ</mi></math></span> = 12.37<span><math><msup><mrow></mrow><mo>∘</mo></msup></math></span>) to the background magnetic field. The relationship between the plasma perturbations and magnetic field perturbations is theoretically derived for slow magnetosonic, Alfv{'e}n, and fast magnetosonic waves based on the magnetohydrodynamic theory. If we take the wave propagation angle <span><math><mi>θ</mi></math></span> = 12.37<span><math><msup><mrow></mrow><mo>∘</mo></msup></math></span> estimated from the MVA method, the theoretically expected density perturbation and velocity perturbation along the background magnetic field are in serious disagreement with the MAVEN data. Through fitting the plasma density perturbation, velocity perturbation, and magnetic field perturbation, it is found that the ion cyclotron wave event can be explained by the superposition of oblique fast magnetosonic waves with a propagation angle of 63<span><math><msup><mrow></mrow><mo>∘</mo></msup></math></span> relative to the background magnetic field and parallel propagating Alfv{'e}n waves. The results are helpful to further understand the physical nature of the observed ion cyclotron wave-related perturbations upstream from the Martian bow shock, and have guiding implications for the re-modeling and numerical simulation of the plasma physical processes therein.</div></div>","PeriodicalId":35730,"journal":{"name":"Chinese Astronomy and Astrophysics","volume":"49 1","pages":"Pages 175-192"},"PeriodicalIF":0.0,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143627863","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Multi-epochs Spectral Variability Analysis of Broad Absorption Lines in QSO SDSS J142225.03+535901.7

Q4 Physics and Astronomy

Chinese Astronomy and Astrophysics

Pub Date : 2025-01-01 DOI: 10.1016/j.chinastron.2025.03.003

He Dong-xu, He Zhi-cheng, Liu Gui-lin, Fang Wen-juan, Shen Lu, Zhu Dan-lei, Chen Ya-qi, Duan Bin

Broad absorption lines (BALs) in quasars are among the most compelling observational evidence for the presence of outflows. BALs commonly exhibit spectral variability, and analyzing such variations helps to constrain the physical models of these outflows. Variations in the ionizing continuum from the central engine of quasars are thought to be the primary mechanism driving most BAL variability. If the BAL absorption troughs in a quasar simultaneously vary (either weakening or strengthening) at different velocities in the same direction, it is highly likely that BAL variability is primarily induced by variations in the ionizing continuum. The quasar SDSS (Sloan Digital Sky Survey) J142225.03+535901.7, with 55 epochs of high signal-to-noise spectra, displays BAL variability. There is a significant anticorrelation (Spearman's correlation test, with a non-correlation probability

p

-value less than 0.05) between the equivalent widths of various velocity components of the BAL and the continuum luminosity. There is no significant anticorrelation between the equivalent widths of these components and the spectral index of the continuum, ruling out that the potential negative correlation between equivalent width and continuum luminosity is caused by the vertical motion of dusty gas along the line of sight. Therefore, it can be inferred that the BAL variability in this source is primarily driven by changes in the ionizing continuum.

{"title":"Multi-epochs Spectral Variability Analysis of Broad Absorption Lines in QSO SDSS J142225.03+535901.7","authors":"He Dong-xu, He Zhi-cheng, Liu Gui-lin, Fang Wen-juan, Shen Lu, Zhu Dan-lei, Chen Ya-qi, Duan Bin","doi":"10.1016/j.chinastron.2025.03.003","DOIUrl":"10.1016/j.chinastron.2025.03.003","url":null,"abstract":"<div><div>Broad absorption lines (BALs) in quasars are among the most compelling observational evidence for the presence of outflows. BALs commonly exhibit spectral variability, and analyzing such variations helps to constrain the physical models of these outflows. Variations in the ionizing continuum from the central engine of quasars are thought to be the primary mechanism driving most BAL variability. If the BAL absorption troughs in a quasar simultaneously vary (either weakening or strengthening) at different velocities in the same direction, it is highly likely that BAL variability is primarily induced by variations in the ionizing continuum. The quasar SDSS (Sloan Digital Sky Survey) J142225.03+535901.7, with 55 epochs of high signal-to-noise spectra, displays BAL variability. There is a significant anticorrelation (Spearman's correlation test, with a non-correlation probability <span><math><mi>p</mi></math></span>-value less than 0.05) between the equivalent widths of various velocity components of the BAL and the continuum luminosity. There is no significant anticorrelation between the equivalent widths of these components and the spectral index of the continuum, ruling out that the potential negative correlation between equivalent width and continuum luminosity is caused by the vertical motion of dusty gas along the line of sight. Therefore, it can be inferred that the BAL variability in this source is primarily driven by changes in the ionizing continuum.</div></div>","PeriodicalId":35730,"journal":{"name":"Chinese Astronomy and Astrophysics","volume":"49 1","pages":"Pages 81-98"},"PeriodicalIF":0.0,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143627858","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Observation Simulation and Orbital Retrieval of the CHES Satellite

Q4 Physics and Astronomy

Chinese Astronomy and Astrophysics

Pub Date : 2025-01-01 DOI: 10.1016/j.chinastron.2025.03.001

Bao Chun-hui , Ji Jiang-hui , Tan Dong-jie , Jin Sheng , Huang Xiu-min , Wang Su , Chen Guo , Dong Yao , Liu Jia-cheng

So far, most of the exoplanets have been discovered with the radial velocity and transient methods. In comparison with these detection techniques, the astrometric method has unique advantages in the determination of planetary orbital parameters and masses. Closeby Habitable Exoplanet Survey (CHES) will search for terrestrial planets in the habitable zone around 100 sun-like stars in the solar system's neighbors (about 10 pc from the sun) using the micro-arcsecond space astrometry method, and further carry out a comprehensive census of nearby planetary systems to obtain the true mass of planets and three-dimensional orbital parameters to establish a complete database of the nearby planetary systems. Based on the observation mode and scientific objectives of the CHES satellite, this work conducted the simulated observations on Alpha Centauri A, a simulated solar system, 51 Peg, and the black hole Cyg X-1, and generated astrometric simulation data. Using two periodic spectra of Lomb-Scargle and BIC (Bayesian information criteria), the signal of the planetary orbit period is analyzed, and the orbit inversion of the planetary system is carried out with the Markov Chain Monte Carlo (MCMC) algorithm. In addition, this work further discusses the influence of the planets around the reference stars on the detection of habitable planets, and the BIC periodic spectrum can be used to identify the reference stars that may have planets around them.

{"title":"Observation Simulation and Orbital Retrieval of the CHES Satellite","authors":"Bao Chun-hui , Ji Jiang-hui , Tan Dong-jie , Jin Sheng , Huang Xiu-min , Wang Su , Chen Guo , Dong Yao , Liu Jia-cheng","doi":"10.1016/j.chinastron.2025.03.001","DOIUrl":"10.1016/j.chinastron.2025.03.001","url":null,"abstract":"<div><div>So far, most of the exoplanets have been discovered with the radial velocity and transient methods. In comparison with these detection techniques, the astrometric method has unique advantages in the determination of planetary orbital parameters and masses. Closeby Habitable Exoplanet Survey (CHES) will search for terrestrial planets in the habitable zone around 100 sun-like stars in the solar system's neighbors (about 10 pc from the sun) using the micro-arcsecond space astrometry method, and further carry out a comprehensive census of nearby planetary systems to obtain the true mass of planets and three-dimensional orbital parameters to establish a complete database of the nearby planetary systems. Based on the observation mode and scientific objectives of the CHES satellite, this work conducted the simulated observations on Alpha Centauri A, a simulated solar system, 51 Peg, and the black hole Cyg X-1, and generated astrometric simulation data. Using two periodic spectra of Lomb-Scargle and BIC (Bayesian information criteria), the signal of the planetary orbit period is analyzed, and the orbit inversion of the planetary system is carried out with the Markov Chain Monte Carlo (MCMC) algorithm. In addition, this work further discusses the influence of the planets around the reference stars on the detection of habitable planets, and the BIC periodic spectrum can be used to identify the reference stars that may have planets around them.</div></div>","PeriodicalId":35730,"journal":{"name":"Chinese Astronomy and Astrophysics","volume":"49 1","pages":"Pages 241-266"},"PeriodicalIF":0.0,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143627865","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Large-scale CO Multi-line Observations of the S187 HII Region

Q4 Physics and Astronomy

Chinese Astronomy and Astrophysics

Pub Date : 2025-01-01 DOI: 10.1016/j.chinastron.2025.03.008

Xu Xiao-yun , Chen Xue-peng , Zhang Shi-yu , Sun Yan

The strong feedback of massive stars profoundly affects the interstellar medium around them, and may trigger the formation of next-generation stars. S187 is a massive star formation region located in the second quadrant of the Milky Way, showing a “Collect and Collapse” triggered star formation pattern. Based on the

^{12} CO

^{13} CO

C^{18} O

(J=1-0, following J=1-0 is omitted for simplicity) spectra line data from the Milky Way Imaging Scroll Painting (MWISP) survey, the basic properties of the molecular cloud in the S187 region were studied, and the feedback of massive stars to molecular cloud was explored. Using GaussPy+ and clustering algorithm, 32 clouds were identified in this region, and the distances of eight of them were measured by combining the star extinction data of Gaia (Global Astrometric Interferometer for Astrophysics) satellite. The relatively dense gas content traced by

^{13} CO

and

C^{18} O

in S187 region is 1-2 orders of magnitude higher than that of molecular clouds in most regions of the second quadrant of the galactic plane. In the S187 region, 243

^{13} CO

and 98

C^{18} O

clumps were identified, among which 7

^{13} CO

and 5

C^{18} O

clumps had the potential to form massive stars. The results show that the feedback of massive stars has an obvious effect on the aggregation of molecular cloud around them, which provides conditions for the formation of the next-generation of massive stars.

{"title":"Large-scale CO Multi-line Observations of the S187 HII Region","authors":"Xu Xiao-yun , Chen Xue-peng , Zhang Shi-yu , Sun Yan","doi":"10.1016/j.chinastron.2025.03.008","DOIUrl":"10.1016/j.chinastron.2025.03.008","url":null,"abstract":"<div><div>The strong feedback of massive stars profoundly affects the interstellar medium around them, and may trigger the formation of next-generation stars. S187 is a massive star formation region located in the second quadrant of the Milky Way, showing a “Collect and Collapse” triggered star formation pattern. Based on the <span><math><mrow><msup><mrow></mrow><mn>12</mn></msup><mrow><mi>CO</mi></mrow></mrow></math></span>/<span><math><mrow><msup><mrow></mrow><mn>13</mn></msup><mrow><mi>CO</mi></mrow></mrow></math></span>/<span><math><mrow><msup><mrow><mi>C</mi></mrow><mn>18</mn></msup><mrow><mi>O</mi></mrow></mrow></math></span> (J=1-0, following J=1-0 is omitted for simplicity) spectra line data from the Milky Way Imaging Scroll Painting (MWISP) survey, the basic properties of the molecular cloud in the S187 region were studied, and the feedback of massive stars to molecular cloud was explored. Using GaussPy+ and clustering algorithm, 32 clouds were identified in this region, and the distances of eight of them were measured by combining the star extinction data of Gaia (Global Astrometric Interferometer for Astrophysics) satellite. The relatively dense gas content traced by <span><math><mrow><msup><mrow></mrow><mn>13</mn></msup><mrow><mi>CO</mi></mrow></mrow></math></span> and <span><math><mrow><msup><mrow><mi>C</mi></mrow><mn>18</mn></msup><mrow><mi>O</mi></mrow></mrow></math></span> in S187 region is 1-2 orders of magnitude higher than that of molecular clouds in most regions of the second quadrant of the galactic plane. In the S187 region, 243 <span><math><mrow><msup><mrow></mrow><mn>13</mn></msup><mrow><mi>CO</mi></mrow></mrow></math></span> and 98 <span><math><mrow><msup><mrow><mi>C</mi></mrow><mn>18</mn></msup><mrow><mi>O</mi></mrow></mrow></math></span> clumps were identified, among which 7 <span><math><mrow><msup><mrow></mrow><mn>13</mn></msup><mrow><mi>CO</mi></mrow></mrow></math></span> and 5 <span><math><mrow><msup><mrow><mi>C</mi></mrow><mn>18</mn></msup><mrow><mi>O</mi></mrow></mrow></math></span> clumps had the potential to form massive stars. The results show that the feedback of massive stars has an obvious effect on the aggregation of molecular cloud around them, which provides conditions for the formation of the next-generation of massive stars.</div></div>","PeriodicalId":35730,"journal":{"name":"Chinese Astronomy and Astrophysics","volume":"49 1","pages":"Pages 99-148"},"PeriodicalIF":0.0,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143627859","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

The Corrections of Sub-picosecond Propagation Time Delays and the Allan Variance of Discontinuous Measurement for the Inter-satellite Time Transfer

Q4 Physics and Astronomy

Chinese Astronomy and Astrophysics

Pub Date : 2025-01-01 DOI: 10.1016/j.chinastron.2025.03.004

He Ke-liang, He Yu-ling, Wang Guo-yong

The asymmetric signal propagation paths between two satellites lead to the unequal time delays at receiving signal time, which should be accurately corrected when solving the clock difference of inter-satellite time transfer. The observation method of clock difference is analysed, the asymmetric signal propagation time delay caused by satellite motion is then derived and reduced, the delay caused by relativistic deflection of light is also calculated using the time transfer function method, and the residual error stability of the propagation time delay correction is evaluated, which improve the correction accuracy of asymmetric signal propagation time delay to 0.1 ps under the current condition of orbit determination. The autocorrelation function representation of Allan variance is extended, and a method of computing the Allan variance error with missing measuring data is proposed based on the statistical method. The effect of missing measuring data on frequency stability calculation of different noises is also analysed. Overall, a systematic correction approach of the propagation time delay and Allan variance with discontinuous measurement for the inter-satellite two-way time transfer has been constructed, which can be used in the clock difference correction of inter-satellite time transfer in the order of ps.

{"title":"The Corrections of Sub-picosecond Propagation Time Delays and the Allan Variance of Discontinuous Measurement for the Inter-satellite Time Transfer","authors":"He Ke-liang, He Yu-ling, Wang Guo-yong","doi":"10.1016/j.chinastron.2025.03.004","DOIUrl":"10.1016/j.chinastron.2025.03.004","url":null,"abstract":"<div><div>The asymmetric signal propagation paths between two satellites lead to the unequal time delays at receiving signal time, which should be accurately corrected when solving the clock difference of inter-satellite time transfer. The observation method of clock difference is analysed, the asymmetric signal propagation time delay caused by satellite motion is then derived and reduced, the delay caused by relativistic deflection of light is also calculated using the time transfer function method, and the residual error stability of the propagation time delay correction is evaluated, which improve the correction accuracy of asymmetric signal propagation time delay to 0.1 ps under the current condition of orbit determination. The autocorrelation function representation of Allan variance is extended, and a method of computing the Allan variance error with missing measuring data is proposed based on the statistical method. The effect of missing measuring data on frequency stability calculation of different noises is also analysed. Overall, a systematic correction approach of the propagation time delay and Allan variance with discontinuous measurement for the inter-satellite two-way time transfer has been constructed, which can be used in the clock difference correction of inter-satellite time transfer in the order of ps.</div></div>","PeriodicalId":35730,"journal":{"name":"Chinese Astronomy and Astrophysics","volume":"49 1","pages":"Pages 219-240"},"PeriodicalIF":0.0,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143627864","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Wulong: A New Main Group Pallasite

Q4 Physics and Astronomy

Chinese Astronomy and Astrophysics

Pub Date : 2025-01-01 DOI: 10.1016/j.chinastron.2025.03.006

Liu Hang-cheng , Zhang Xin-ru , He Wen-zhong , Liao Shi-yong , Hsu Wei-biao , Jiang Yun

As the fragments of differentiated asteroids in the early solar system, pallasites record deep-mantle and core processes. As such, studying the origin of pallasites could help us understand the formation and differentiation processes governing the evolution of planets. Wulong pallasite was found in Inner Mongolia, China around 1992, but didn't get much attention until 2020. In this study, we reported the detailed petrography and mineralogy, oxygen isotopic composition, and metal phase chemistry of Wulong pallasite. Wulong pallasite is mainly composed of olivine (

\sim

72.7 vol.%), Fe-Ni metal (

\sim

26.2 vol.%), troilite (

\sim

0.6 vol.%), schreibersite (

\sim

0.4 vol.%), and chromite (

\sim

0.1 vol.%) etc. Olivine (Fa

_{12.5 \pm 0.2}

) and chromite (Al

#

\sim

15.2

\pm

0.9, Fe

#

\sim

67.9

\pm

1.5) compositions are homogeneous, and no chemical zoning is observed. Siderophile element contents of a metal phase are Ni, 7.71 wt.%; Ga, 17.8

μ

g/g; and Ge, 26.2

μ

g/g. The mean

δ

^{18}

O value is 3.04

\pm

0.01‰,

Δ

^{17}

O value is

-

0.18

\pm

0.01‰. In terms of the Fa value of olivine, metal phase chemistry, and oxygen isotope ratios, Wulong could be a new member of main group pallasite.

{"title":"Wulong: A New Main Group Pallasite","authors":"Liu Hang-cheng , Zhang Xin-ru , He Wen-zhong , Liao Shi-yong , Hsu Wei-biao , Jiang Yun","doi":"10.1016/j.chinastron.2025.03.006","DOIUrl":"10.1016/j.chinastron.2025.03.006","url":null,"abstract":"<div><div>As the fragments of differentiated asteroids in the early solar system, pallasites record deep-mantle and core processes. As such, studying the origin of pallasites could help us understand the formation and differentiation processes governing the evolution of planets. Wulong pallasite was found in Inner Mongolia, China around 1992, but didn't get much attention until 2020. In this study, we reported the detailed petrography and mineralogy, oxygen isotopic composition, and metal phase chemistry of Wulong pallasite. Wulong pallasite is mainly composed of olivine (<span><math><mo>∼</mo></math></span> 72.7 vol.%), Fe-Ni metal (<span><math><mo>∼</mo></math></span> 26.2 vol.%), troilite (<span><math><mo>∼</mo></math></span> 0.6 vol.%), schreibersite (<span><math><mo>∼</mo></math></span> 0.4 vol.%), and chromite (<span><math><mo>∼</mo></math></span> 0.1 vol.%) etc. Olivine (Fa<span><math><msub><mrow></mrow><mrow><mn>12.5</mn><mo>±</mo><mn>0.2</mn></mrow></msub></math></span>) and chromite (Al<span><math><mo>#</mo></math></span><span><math><mo>∼</mo></math></span>15.2 <span><math><mo>±</mo></math></span> 0.9, Fe<span><math><mo>#</mo></math></span><span><math><mo>∼</mo></math></span> 67.9 <span><math><mo>±</mo></math></span> 1.5) compositions are homogeneous, and no chemical zoning is observed. Siderophile element contents of a metal phase are Ni, 7.71 wt.%; Ga, 17.8 <span><math><mi>μ</mi></math></span>g/g; and Ge, 26.2 <span><math><mi>μ</mi></math></span>g/g. The mean <span><math><mi>δ</mi></math></span><span><math><msup><mrow></mrow><mn>18</mn></msup></math></span>O value is 3.04 <span><math><mo>±</mo></math></span> 0.01‰, <span><math><mstyle><mi>Δ</mi></mstyle></math></span><span><math><msup><mrow></mrow><mn>17</mn></msup></math></span>O value is <span><math><mo>−</mo></math></span>0.18 <span><math><mo>±</mo></math></span> 0.01‰. In terms of the Fa value of olivine, metal phase chemistry, and oxygen isotope ratios, Wulong could be a new member of main group pallasite.</div></div>","PeriodicalId":35730,"journal":{"name":"Chinese Astronomy and Astrophysics","volume":"49 1","pages":"Pages 1-16"},"PeriodicalIF":0.0,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143627928","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

A Study of Pulse Nulling in PSR J1701 – 3726

Q4 Physics and Astronomy

Chinese Astronomy and Astrophysics

Pub Date : 2025-01-01 DOI: 10.1016/j.chinastron.2025.03.002

Cai Yan-qing , Li Qing-ying , Tian Jie , Li Wei , Dang Shi-jun , Shang Lun-hua , Xu Xin , Zhi Qi-jun , Wu Jia-chao

Using the observation data of Parkes 64 m radio telescope at a central frequency of 1369 MHz, the pulse nulling phenomenon of PSR J1701–3726 was analyzed. It is found that the pulse nulling phenomenon of this pulsar has quasi-periodic, and the quasi-period value approximately is 81.25

P

, where

P

is the rotation period, and the pulse nulling ratio NF (Nulling Fraction) is calculated to be 27%

\pm

0.97%. Further study on the change of relative energy in the on-pulse region over time shows that there are four different switching modes a, b, c, and d between null state and burst state, among which mode a occurs 23 times, mode b occurs 6 times, mode c occurs 5 times, and mode d occurs 79 times, indicating that there may be some randomness in state transitions.

引用次数: 0

Reducing the Measuring Error of Solar Magnetic Field by Stereo Observation

Q4 Physics and Astronomy

Chinese Astronomy and Astrophysics

Pub Date : 2025-01-01 DOI: 10.1016/j.chinastron.2025.03.010

Zeng Bai-yu , Guo Yang , Li Chuan , Li Zhen , You Wei , Huang Fan , Zhang Lan-qiang , Yang Jin-sheng

Observing the solar magnetic field from a single point, we can measure the magnetic field component along the line of sight and the magnetic field component perpendicular to the line of sight (transverse field). However, the accuracy of transverse field is one order of magnitude lower than that of the radial field, and there is a

180^{\circ}

uncertainty in the direction of the transverse magnetic field. The goal of this paper is to improve the accuracy of the transverse field of the solar magnetic field. It is considered to observe the magnetic field at the Sun-Earth L5 point and Earth simultaneously, and the error reduction can be obtained through model construction and data analysis. The specific methods are as follows. Coordinate relations of magnetic fields at Earth and L5 point are obtained by spherical trigonometry formula, and the corrected errors of the transverse magnetic field at L1 points are obtained by error propagation formula. Then, we calculate the error distribution of the solar magnetic field data, and simulate two data conforming to the solar magnetic field distribution, which are respectively used as the error diagram of Earth and L5 point. Finally, by combining the data of Earth and L5 point, the corrected data whose transverse field error at Earth has been reduced, are obtained and compared with the original transverse field data. It is found that the transverse field error of Earth can be reduced to about 17% of the original.

{"title":"Reducing the Measuring Error of Solar Magnetic Field by Stereo Observation","authors":"Zeng Bai-yu , Guo Yang , Li Chuan , Li Zhen , You Wei , Huang Fan , Zhang Lan-qiang , Yang Jin-sheng","doi":"10.1016/j.chinastron.2025.03.010","DOIUrl":"10.1016/j.chinastron.2025.03.010","url":null,"abstract":"<div><div>Observing the solar magnetic field from a single point, we can measure the magnetic field component along the line of sight and the magnetic field component perpendicular to the line of sight (transverse field). However, the accuracy of transverse field is one order of magnitude lower than that of the radial field, and there is a <span><math><msup><mn>180</mn><mo>∘</mo></msup></math></span> uncertainty in the direction of the transverse magnetic field. The goal of this paper is to improve the accuracy of the transverse field of the solar magnetic field. It is considered to observe the magnetic field at the Sun-Earth L5 point and Earth simultaneously, and the error reduction can be obtained through model construction and data analysis. The specific methods are as follows. Coordinate relations of magnetic fields at Earth and L5 point are obtained by spherical trigonometry formula, and the corrected errors of the transverse magnetic field at L1 points are obtained by error propagation formula. Then, we calculate the error distribution of the solar magnetic field data, and simulate two data conforming to the solar magnetic field distribution, which are respectively used as the error diagram of Earth and L5 point. Finally, by combining the data of Earth and L5 point, the corrected data whose transverse field error at Earth has been reduced, are obtained and compared with the original transverse field data. It is found that the transverse field error of Earth can be reduced to about 17% of the original.</div></div>","PeriodicalId":35730,"journal":{"name":"Chinese Astronomy and Astrophysics","volume":"49 1","pages":"Pages 160-174"},"PeriodicalIF":0.0,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143627861","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Research on Starlink Ephemeris Published by SpaceX

Q4 Physics and Astronomy

Chinese Astronomy and Astrophysics

Pub Date : 2025-01-01 DOI: 10.1016/j.chinastron.2025.03.005

Liu Ai-rong , Xiong Yong-qing , Hui Jian-jiang , Xu Xiao-li , Gong Jun

Faced with the significant disruption of normal space activities caused by Starlink satellites, the Starlink ephemeris published by SpaceX provides an opportunity for relevant research on Starlink satellites. However, due to the lack of clear instructions, it is challenging to utilize the data further. Analysis of the ephemeris file reveals that it primarily represents the predicted orbit for the next 3 d. Research on mean orbital elements indicates that the front part of the ephemeris is an extrapolated orbit with perturbations up to at least the 20th order of Earth's gravitational field, while the latter part is a design orbit with

J_{2}

perturbation. The ephemeris includes covariance information, providing accuracy details. The covariance indicates that the accuracy of the ephemeris for satellites located in parking and working orbits is better than 2 km in the first day, while the accuracy of satellites in raising orbit increases rapidly to thousands of meters in less than half a day. Utilizing the designed orbit of the ephemeris enables a more accurate analysis of constellation configuration, especially the designated position of each satellite, thus facilitating the identification and tracking of Starlink satellites. The study provides valuable insights for the extensive application of Starlink ephemeris, serving as a beneficial reference for maneuver detection and collision warnings of Starlink satellites.

{"title":"Research on Starlink Ephemeris Published by SpaceX","authors":"Liu Ai-rong , Xiong Yong-qing , Hui Jian-jiang , Xu Xiao-li , Gong Jun","doi":"10.1016/j.chinastron.2025.03.005","DOIUrl":"10.1016/j.chinastron.2025.03.005","url":null,"abstract":"<div><div>Faced with the significant disruption of normal space activities caused by Starlink satellites, the Starlink ephemeris published by SpaceX provides an opportunity for relevant research on Starlink satellites. However, due to the lack of clear instructions, it is challenging to utilize the data further. Analysis of the ephemeris file reveals that it primarily represents the predicted orbit for the next 3 d. Research on mean orbital elements indicates that the front part of the ephemeris is an extrapolated orbit with perturbations up to at least the 20th order of Earth's gravitational field, while the latter part is a design orbit with <span><math><msub><mi>J</mi><mn>2</mn></msub></math></span> perturbation. The ephemeris includes covariance information, providing accuracy details. The covariance indicates that the accuracy of the ephemeris for satellites located in parking and working orbits is better than 2 km in the first day, while the accuracy of satellites in raising orbit increases rapidly to thousands of meters in less than half a day. Utilizing the designed orbit of the ephemeris enables a more accurate analysis of constellation configuration, especially the designated position of each satellite, thus facilitating the identification and tracking of Starlink satellites. The study provides valuable insights for the extensive application of Starlink ephemeris, serving as a beneficial reference for maneuver detection and collision warnings of Starlink satellites.</div></div>","PeriodicalId":35730,"journal":{"name":"Chinese Astronomy and Astrophysics","volume":"49 1","pages":"Pages 193-218"},"PeriodicalIF":0.0,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143627862","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Advance in the Research of Stellar Superflares

Q4 Physics and Astronomy

Chinese Astronomy and Astrophysics

Pub Date : 2025-01-01 DOI: 10.1016/j.chinastron.2025.03.009

Yong Hao-ran , Lin Jun

The Solar flare is one of the most violent eruptive phenomena in the Solar system, which releases energy up to

10^{25}

J in tens of minutes. With the development of observational techniques, similar flare events have been observed on stars, with typical energy of 10 to

10^{4}

times that of Solar flares, which is known as the superflare. Studies of stellar superflares and their mechanisms are not only important for understanding the internal structure, evolution, and magnetic activities of stars, but also for exploring the habitability and extraterrestrial life on exoplanets. A brief introduction is first given on Solar flares and the associated phenomena of magnetic activities, stellar magnetic field, and superflares of stars. Then, current detection methods and research results of stellar superflares are reviewed in terms of selection, energy evaluation, starspots, and the statistical relationships between the flare parameters and stellar parameters. Meanwhile, a comparison is made with the theories of Solar flares and the related physical processes to explore their similarities and connections. Finally, a summary is made and the related further work is also discussed.

太阳耀斑是太阳系中最剧烈的爆发现象之一，它在数十分钟内释放出高达 1025 焦耳的能量。随着观测技术的发展，在恒星上也观测到了类似的耀斑事件，其典型能量是太阳耀斑的 10 到 104 倍，这就是所谓的超级耀斑。对恒星超级耀斑及其机制的研究不仅对了解恒星的内部结构、演化和磁活动非常重要，而且对探索系外行星的宜居性和系外生命也非常重要。本文首先简要介绍了太阳耀斑及其相关的磁活动现象、恒星磁场和恒星超级耀斑。然后，从耀斑的选择、能量评估、星斑以及耀斑参数与恒星参数之间的统计关系等方面回顾了目前恒星超级耀斑的探测方法和研究成果。同时，将其与太阳耀斑理论及相关物理过程进行比较，探讨两者的相似性和联系。最后，进行了总结并讨论了相关的进一步工作。

{"title":"Advance in the Research of Stellar Superflares","authors":"Yong Hao-ran , Lin Jun","doi":"10.1016/j.chinastron.2025.03.009","DOIUrl":"10.1016/j.chinastron.2025.03.009","url":null,"abstract":"<div><div>The Solar flare is one of the most violent eruptive phenomena in the Solar system, which releases energy up to <span><math><msup><mn>10</mn><mn>25</mn></msup></math></span> J in tens of minutes. With the development of observational techniques, similar flare events have been observed on stars, with typical energy of 10 to <span><math><msup><mn>10</mn><mn>4</mn></msup></math></span> times that of Solar flares, which is known as the superflare. Studies of stellar superflares and their mechanisms are not only important for understanding the internal structure, evolution, and magnetic activities of stars, but also for exploring the habitability and extraterrestrial life on exoplanets. A brief introduction is first given on Solar flares and the associated phenomena of magnetic activities, stellar magnetic field, and superflares of stars. Then, current detection methods and research results of stellar superflares are reviewed in terms of selection, energy evaluation, starspots, and the statistical relationships between the flare parameters and stellar parameters. Meanwhile, a comparison is made with the theories of Solar flares and the related physical processes to explore their similarities and connections. Finally, a summary is made and the related further work is also discussed.</div></div>","PeriodicalId":35730,"journal":{"name":"Chinese Astronomy and Astrophysics","volume":"49 1","pages":"Pages 17-80"},"PeriodicalIF":0.0,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143627929","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

下一页尾页

类型

全部化学•材料生命科学医学物理工程技术环境•农林材料科学地球科学法学管理学化学环境科学与生态学计算机科学教育学经济学农林科学人文科学生物学数学物理与天体物理心理学综合性期刊其他工业工程理学历史学农学文学信息工程

数据库

全部 ACS Publications Elsevier ieeexplore Springer The Royal Society of Chemistry Wiley

期刊

Chinese Astronomy and Astrophysics

全部 Acc. Chem. Res. ACS Applied Bio Materials ACS Appl. Electron. Mater. ACS Appl. Energy Mater. ACS Appl. Mater. Interfaces ACS Appl. Nano Mater. ACS Appl. Polym. Mater. ACS BIOMATER-SCI ENG ACS Catal. ACS Cent. Sci. ACS Chem. Biol. ACS Chemical Health & Safety ACS Chem. Neurosci. ACS Comb. Sci. ACS Earth Space Chem. ACS Energy Lett. ACS Infect. Dis. ACS Macro Lett. ACS Mater. Lett. ACS Med. Chem. Lett. ACS Nano ACS Omega ACS Photonics ACS Sens. ACS Sustainable Chem. Eng. ACS Synth. Biol. Anal. Chem. BIOCHEMISTRY-US Bioconjugate Chem. BIOMACROMOLECULES Chem. Res. Toxicol. Chem. Rev. Chem. Mater. CRYST GROWTH DES ENERG FUEL Environ. Sci. Technol. Environ. Sci. Technol. Lett. Eur. J. Inorg. Chem. IND ENG CHEM RES Inorg. Chem. J. Agric. Food. Chem. J. Chem. Eng. Data J. Chem. Educ. J. Chem. Inf. Model. J. Chem. Theory Comput. J. Med. Chem. J. Nat. Prod. J PROTEOME RES J. Am. Chem. Soc. LANGMUIR MACROMOLECULES Mol. Pharmaceutics Nano Lett. Org. Lett. ORG PROCESS RES DEV ORGANOMETALLICS J. Org. Chem. J. Phys. Chem. J. Phys. Chem. A J. Phys. Chem. B J. Phys. Chem. C J. Phys. Chem. Lett. Analyst Anal. Methods Biomater. Sci. Catal. Sci. Technol. Chem. Commun. Chem. Soc. Rev. CHEM EDUC RES PRACT CRYSTENGCOMM Dalton Trans. Energy Environ. Sci. ENVIRON SCI-NANO ENVIRON SCI-PROC IMP ENVIRON SCI-WAT RES Faraday Discuss. Food Funct. Green Chem. Inorg. Chem. Front. Integr. Biol. J. Anal. At. Spectrom. J. Mater. Chem. A J. Mater. Chem. B J. Mater. Chem. C Lab Chip Mater. Chem. Front. Mater. Horiz. MEDCHEMCOMM Metallomics Mol. Biosyst. Mol. Syst. Des. Eng. Nanoscale Nanoscale Horiz. Nat. Prod. Rep. New J. Chem. Org. Biomol. Chem. Org. Chem. Front. PHOTOCH PHOTOBIO SCI PCCP Polym. Chem.

﹀