Research in Astronomy and Astrophysics最新文献

The design of GECAM Scientific Ground Segment GECAM 科学地面段的设计

Research in Astronomy and Astrophysics Pub Date : 2024-07-27 DOI: 10.1088/1674-4527/ad683a

Shijie Zheng, Liming Song, Xiang Ma, Ping Wang, Rui Qiao, Yue Huang, Xiao-Yun Zhao, Hongmei Zhang, Xiaobo Li, Shaolin Xiong

引用次数: 0

Supermassive primordial black holes for nano-Hertz gravitational waves and high-redshift JWST galaxies 纳赫兹引力波和高红移 JWST 星系的超大质量原始黑洞

Research in Astronomy and Astrophysics Pub Date : 2024-07-27 DOI: 10.1088/1674-4527/ad683d

Hai-Long Huang, Yong Cai, Jun-Qian Jiang, Jun Zhang, Yun-song Piao

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Charged Particles Capture Cross-Section by a Weakly Charged Schwarzschild Black Hole 弱电荷施瓦兹柴尔德黑洞的带电粒子捕获截面

Research in Astronomy and Astrophysics Pub Date : 2024-07-16 DOI: 10.1088/1674-4527/ad63e6

A. Al Zahrani, Ahmad Al-Jamaa

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Understanding the activity performance of comets 38P/Stephan-Oterma, 64P/Swift-Gehrels and C/2017 M4 (ATLAS) through broadband photometric observations 通过宽带测光观测了解 38P/Stephan-Oterma、64P/Swift-Gehrels 和 C/2017 M4 (ATLAS) 彗星的活动性能

Research in Astronomy and Astrophysics Pub Date : 2024-07-15 DOI: 10.1088/1674-4527/ad6350

Xuan Zhang, Jin-Zhong Liu, Letian Wang

{"title":"Understanding the activity performance of comets 38P/Stephan-Oterma, 64P/Swift-Gehrels and C/2017 M4 (ATLAS) through broadband photometric observations","authors":"Xuan Zhang, Jin-Zhong Liu, Letian Wang","doi":"10.1088/1674-4527/ad6350","DOIUrl":"https://doi.org/10.1088/1674-4527/ad6350","url":null,"abstract":"\u0000 In this work, we report observations of three comets: 38P/Stephan-Oterma, 64P/Swift-Gehrels, and C/2017 M4 (ATLAS), conducted with the Nanshan one-meter wide- field telescope in August and November 2018, and January 2019. We extracted morphological features through image enhancement techniques and calculated the dust activity parameter, Afρ, along with dust mass loss rates and coma color indices using broadband photometric data. Our morphological analysis uncovered a spectrum of dust characteristics among the ob- served comets, ranging from a significant twisted structure in comet 38P/Stephan-Oterma’s coma to the regular coma envelope surrounding comet 64P/Swift-Gehrels. The Afρ values varied between 148.8 ± 0.3 cm for 64P/Swift-Gehrels and 1118.5 ± 6.2 cm for C/2017 M4 (ATLAS) (measured within a reference aperture radius of ρ = 6 arcsec), indicating a range from moderate to high activity levels. Dust mass loss rates were estimated from 328.1 kg/s for comet 64P/Swift-Gehrels to 1395.5 kg/s for comet C/2017 M4 (ATLAS). The color indices of comets 38P/Stephan-Oterma and C/2017 M4 (ATLAS) closely resemble the average col- ors of active short-period comets (SPCs) and active long-period comets (LPCs), respectively. In contrast, 64P/Swift-Gehrels exhibit a significantly bluer hue than typical Jupiter Family Comets (JFCs).","PeriodicalId":509923,"journal":{"name":"Research in Astronomy and Astrophysics","volume":" 3","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-07-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141833449","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

X-ray Sources Classification Using Machine Learning: A Study with EP-WXT Pathfinder LEIA 利用机器学习进行 X 射线源分类：EP-WXT 探路者 LEIA 研究

Research in Astronomy and Astrophysics Pub Date : 2024-07-15 DOI: 10.1088/1674-4527/ad634f

Xiaoxiong Zuo, Yihan Tao, Yuan Liu, Yunfei Xu, Wenda Zhang, Haiwu Pan, Hui Sun, Zhen Zhang, Chenzhou Cui, W. Yuan

{"title":"X-ray Sources Classification Using Machine Learning: A Study with EP-WXT Pathfinder LEIA","authors":"Xiaoxiong Zuo, Yihan Tao, Yuan Liu, Yunfei Xu, Wenda Zhang, Haiwu Pan, Hui Sun, Zhen Zhang, Chenzhou Cui, W. Yuan","doi":"10.1088/1674-4527/ad634f","DOIUrl":"https://doi.org/10.1088/1674-4527/ad634f","url":null,"abstract":"\u0000 X-ray observations play a crucial role in time-domain astronomy. The Einstein Probe (EP), a recently launched X-ray astronomical satellite, emerges as a forefront player in the field of time-domain astronomy and high-energy astrophysics. With a focus on sys tematic surveys in the soft X-ray band, EP aims to discover high-energy transients and monitor variable sources in the universe. To achieve these objectives, a quick and reli able classification of observed sources is essential. In this study, we developed a machine learning classifier for autonomous source classification using data from the EP-WXT Pathfinder - Lobster Eye Imager for Astronomy (LEIA) and EP-WXT simulations. The proposed random forest classifier, built on selected features derived from light curves, en ergy spectra, and location information, achieves an accuracy of approximately 95% on EP simulation data and 98% on LEIA observational data. The classifier is integrated into the LEIA data processing pipeline, serving as a tool for manual validation and rapid classifi cation during observations. This paper presents an efficient method for the classification of X-ray sources based on single observations, along with implications of most effective features for the task. This work facilitates rapid source classification for the EP mission and also provides valuable insights into feature selection and classification techniques for enhancing the efficiency and accuracy of X-ray source classification that can be adapted to other X-ray telescope data.","PeriodicalId":509923,"journal":{"name":"Research in Astronomy and Astrophysics","volume":"100 3","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-07-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141647164","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Photometric studies of EV Cnc and AH Cnc in the open cluster M 67 开放星团 M 67 中 EV Cnc 和 AH Cnc 的光度研究

Research in Astronomy and Astrophysics Pub Date : 2024-07-15 DOI: 10.1088/1674-4527/ad634e

Mamatha Rani Gaddam, K. Sriram, Deblina Lahiri, Vijaya Annemalla

{"title":"Photometric studies of EV Cnc and AH Cnc in the open cluster M 67","authors":"Mamatha Rani Gaddam, K. Sriram, Deblina Lahiri, Vijaya Annemalla","doi":"10.1088/1674-4527/ad634e","DOIUrl":"https://doi.org/10.1088/1674-4527/ad634e","url":null,"abstract":"\u0000 Contact binaries at various stages of evolution unveil various operating mechanism that drives them. We report the photometric and period variations analysis of two contact binaries EV Cnc and AH Cnc in open cluster M 67. We observed the cluster from the JCBT 1.3 m telescope and utilized TESS and Kepler observations. The photometric solutions of EV Cnc and AH Cnc revealed a mass ratio of q$sim$0.40 & $sim$0.15 with an inclination of i=42$^{circ}$ & 87$^{circ}$. These solutions suggest that EV Cnc is probably a marginal contact binary and AH Cnc is a deep low mass ratio contact binary. The study of O-C variation analysis indicates that for both the systems, the period is increasing which suggests the mass transfer is occurring from secondary to primary. In the case of AH Cnc and based on simulations by randomly varying the time of minima to fit the LITE solution, we noted the third body orbital period to be around P$_{3}$ = 26.82 $pm$ 2.54 years, which is different from earlier reported values and conclude that future observations are required to confirm this scenario. We compare these two systems with other similar contact binaries to get an estimate of the final configuration of the respective systems.","PeriodicalId":509923,"journal":{"name":"Research in Astronomy and Astrophysics","volume":"35 37","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-07-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141645658","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

The Astrometric Performance of the China Space Station Telescope (CSST) Sky Survey in Extending the Gaia Celestial Reference Frame 中国空间站望远镜（CSST）巡天在扩展盖娅天体参照系中的天文测量性能

Research in Astronomy and Astrophysics Pub Date : 2024-07-11 DOI: 10.1088/1674-4527/ad621e

Jun Yao, Jia-cheng Liu, Niu Liu, Zi Zhu, Zhen-Wei Wang

{"title":"The Astrometric Performance of the China Space Station Telescope (CSST) Sky Survey in Extending the Gaia Celestial Reference Frame","authors":"Jun Yao, Jia-cheng Liu, Niu Liu, Zi Zhu, Zhen-Wei Wang","doi":"10.1088/1674-4527/ad621e","DOIUrl":"https://doi.org/10.1088/1674-4527/ad621e","url":null,"abstract":"\u0000 The multi-color imaging sky survey conducted by the China Space Station Telescope (CSST) holds significant promise for advancing the development of the celestial reference frame. In this study, we focus on assessing the astrometric performance of the CSST celestial reference frame (CSST-CRF) in extending the Gaia Celestial Reference Frame 3 (Gaia-CRF3). Firstly, the orientation precision of the CSST reference frame is evaluated using a simulated set of extragalactic sources with CSST g magnitudes ranging from 18 to 25 mag. The estimated orientation uncertainty caused by random error insignificantly affects the alignment between Gaia-CRF3 and the CSST-CRF. Then, the systematic effect of incomplete CSST sky coverage on the alignment between CSST-CRF and Gaia-CRF3 is discussed by analyzing the differences between the subset of Gaia-CRF3 in the CSST observation region ($rm{Gaiambox{-}CRF3'}$) and Gaia-CRF3 as a whole. Using the third International Celestial Reference Frame (ICRF3) S/X band as an intermediate reference frame, the orientation offset between $rm{Gaiambox{-}CRF3'}$ and Gaia-CRF3 is estimated to be 20 $rm{mu as}$. This offset is marginally larger than the orientation offset between Gaia-CRF3 and the ICRF3, approximately 15 $rm{mu as}$. The residual spin and glide rate of $rm{Gaiambox{-}CRF3'}$ are derived from the proper motions, consistent with that of Gaia-CRF3 within the formal error. Finally, we explore the role of CSST in establishing a multi-band celestial reference frame by comparing its limiting magnitude and observation accuracy with existing catalogs in the infrared and ultraviolet bands. Thanks to its broad wavelength coverage and high-precision measurements, CSST is well-positioned to make significant contributions to the development of a multi-band celestial reference frame.","PeriodicalId":509923,"journal":{"name":"Research in Astronomy and Astrophysics","volume":"27 9","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-07-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141658702","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Pulsations of Three Rapidly Oscillating Ap Stars TIC 96315731, TIC 72392575, and TIC 318007796 三颗快速振荡 Ap 星的脉动 TIC 96315731、TIC 72392575 和 TIC 318007796

Research in Astronomy and Astrophysics Pub Date : 2024-07-11 DOI: 10.1088/1674-4527/ad621d

Haijian Zhong, Dongxiang Shen, Chun-Hua Zhu, He-Lei Liu, Sufen Guo, Guo-Liang lv

{"title":"Pulsations of Three Rapidly Oscillating Ap Stars TIC 96315731, TIC 72392575, and TIC 318007796","authors":"Haijian Zhong, Dongxiang Shen, Chun-Hua Zhu, He-Lei Liu, Sufen Guo, Guo-Liang lv","doi":"10.1088/1674-4527/ad621d","DOIUrl":"https://doi.org/10.1088/1674-4527/ad621d","url":null,"abstract":"\u0000 We analyze the frequencies of three known roAp stars, TIC 96315731, TIC 72392575, and TIC 318007796, using the light curves from the Transiting Exoplanet Survey Satellite (TESS). For TIC 96315731, the rotational and pulsational frequencies are 0.1498360 d-1 and 165.2609 d-1, respectively. In the case of TIC 72392575, the rotational frequency is 0.25551 d-1. We detect a quintuplet of pulsation frequencies with a center frequency of 135.9233 d-1, along with two signals within the second pair of rotational sidelobes of the quintuplet separated by the rotation frequency. These two signals may correspond to the frequencies of a dipole mode. In TIC 318007796, the rotational and pulsational frequencies are 0.2475021 d-1, 192.73995 d-1, and 196.33065 d-1, respectively. Based on the oblique pulsator model, we calculate the rotation inclination (i) and magnetic obliquity angle (β) for the stars, which provides the geometry of the pulsation modes. Combining the phases of the frequency quintuplets, the pulsation amplitude and phase modulation curves, and the results of spherical harmonic decomposition, we conclude that the pulsation modes of frequency quintuplets in TIC 96315731, TIC 72392575, and TIC 318007796 correspond to distorted dipole mode, distorted quadrupole mode, and distorted dipole mode, respectively.","PeriodicalId":509923,"journal":{"name":"Research in Astronomy and Astrophysics","volume":"141 20","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-07-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141655985","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Photometric and Spectroscopic study of Ten Low Mass Ratio ContactBinary Systems: Orbital Stability, O’Connell Effect and Infra-redCalcium Line Filling. 十个低质量比接触双星系统的光度和光谱研究：轨道稳定性、奥康奈尔效应和红外钙线填充。

Research in Astronomy and Astrophysics Pub Date : 2024-07-11 DOI: 10.1088/1674-4527/ad621f

S. Wadhwa, Adam Popowicz, R. Michel, Petar Kosti´c, Oliver Vince, Nick F. H. Tothill, Ain Y. DeHorta, Miroslav Filipovic´

{"title":"Photometric and Spectroscopic study of Ten Low Mass Ratio ContactBinary Systems: Orbital Stability, O’Connell Effect and Infra-redCalcium Line Filling.","authors":"S. Wadhwa, Adam Popowicz, R. Michel, Petar Kosti´c, Oliver Vince, Nick F. H. Tothill, Ain Y. DeHorta, Miroslav Filipovic´","doi":"10.1088/1674-4527/ad621f","DOIUrl":"https://doi.org/10.1088/1674-4527/ad621f","url":null,"abstract":"\u0000 Low mass ratio contact binary systems are more likely to have unstable orbits and potentially merge. In addition, such systems exhibit characteristics such as starspots and high energy emissions (UV) suggestive of chromospheric and magnetic activity. Light curve modelling of ten contact binary systems is reported. All were found to be of extreme low mass ratio ranging from 0.122 to 0.24 and three were found to be potentially unstable and possible merger candidates. Filling of the infrared Calcium absorption lines is a marker of increased chromospheric activity. We use the available LAMOST spectra along with matched standard spectra (broadened for rotation) to measure the excess filling of the central core depression flux of the two main infrared Calcium absorption lines λ8542 and λ8662. We find that all reported contact binaries have excess filling of the core flux in the infrared Calcium lines. Three of the systems reported were also observed by the GALEX mission and we find that all three have features of excess ultraviolet emissions further adding evidence for increased chromospheric activity in low mass ratio contact binaries. Analysis of both orbital stability and absorption line filling is dependent on the determination of geometric and absolute parameters from light curve modelling. Not an insignificant number of contact binary light curves exhibit the O’Connell effect, usually attributed to starspots. We discuss the inclusion of starspots in light curve solutions and how they influence the geometric and absolute parameters.","PeriodicalId":509923,"journal":{"name":"Research in Astronomy and Astrophysics","volume":"91 9","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-07-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141657741","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Detection of Increasing Gamma-ray Emissions from 4FGL J1718.5+4237 with Fermi-LAT 用费米-LAT探测4FGL J1718.5+4237发射的不断增加的伽马射线

Research in Astronomy and Astrophysics Pub Date : 2024-07-09 DOI: 10.1088/1674-4527/ad607d

Jiao Zheng, Peng-fei Zhang, Li Zhang

{"title":"Detection of Increasing Gamma-ray Emissions from 4FGL J1718.5+4237 with Fermi-LAT","authors":"Jiao Zheng, Peng-fei Zhang, Li Zhang","doi":"10.1088/1674-4527/ad607d","DOIUrl":"https://doi.org/10.1088/1674-4527/ad607d","url":null,"abstract":"\u0000 We report a gradual brightening γ-ray source, 4FGL J1718.5+4237, in 0.1– 500.0 GeV, which may be associated with a blazar NVSS J171822+423948 with a redshift of ~2.7. We analyzed 15.25 yr of γ-ray data recorded by the Large Area Telescope on board the Fermi Gamma-ray Space Telescope and detected significant γ-ray emissions in the di- rection of the blazar with a test statistic (TS) of ~135. Based on timing analysis using a 1-year time bin, we have observed a gradual brightening γ-ray emissions from the target. In our analysis, we categorize them into two states: Quiet (TS~0) and Loud (TS~226) states, with the distinction occurring in August 2016 (MJD 57602.69). From the Quiet state to the brightest period (the last data point), the γ-ray flux in the 0.1–500.0 GeV increased by more than 12-fold from <0.2×10−8 photons cm−1 s−1 to 2.6×10−8 photons cm−1 s−1. Additionally, we studied the spectral properties in detail for the Loud state and the overall data. While no significant variation was detected, both exhibited a spectral index Γ of ~2.6. The origin of the brightening γ-ray emissions from the target is not yet clear. Future long-term multi- wavelength observations and studies will provide insight into the astrophysical mechanisms of the target.","PeriodicalId":509923,"journal":{"name":"Research in Astronomy and Astrophysics","volume":"109 45","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-07-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141665867","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0