Pub Date : 2020-03-01DOI: 10.31577/caosp.2020.50.2.565
A. Prša
This contribution highlights some of the open questions identified by the binary star community in attendance, based on a 45-min discussion in lieu of an ex-cathedra talk. As photometric and spectroscopic data accuracy reach unprecedented levels, it is crucial to identify and address these open questions. In what follows are concise minutes from the discussion with minimal commentary, in an effort to stimulate further discussion and promote focused studies dedicating to answering these open questions.
{"title":"The brave new world of eclipsing binary modeling","authors":"A. Prša","doi":"10.31577/caosp.2020.50.2.565","DOIUrl":"https://doi.org/10.31577/caosp.2020.50.2.565","url":null,"abstract":"This contribution highlights some of the open questions identified by the binary star community in attendance, based on a 45-min discussion in lieu of an ex-cathedra talk. As photometric and spectroscopic data accuracy reach unprecedented levels, it is crucial to identify and address these open questions. In what follows are concise minutes from the discussion with minimal commentary, in an effort to stimulate further discussion and promote focused studies dedicating to answering these open questions.","PeriodicalId":50617,"journal":{"name":"Contributions of the Astronomical Observatory Skalnate Pleso","volume":null,"pages":null},"PeriodicalIF":0.5,"publicationDate":"2020-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73861736","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-03-01DOI: 10.31577/caosp.2020.50.2.627
J. Rukmini, D. S. Priya, P. Jishnu, G. V. Kumar
TYC 3315-1807-1 is an sdB+dM binary first reported by Kawka et al. (2010). Archival photometric data indicate the presence of a secondary companion causing a large reflection effect. Spectroscopic observations of the object were carried out from Vainu Bappu Observatory, Kavalur, to probe the nature of the secondary companion and to understand the post commonenvelope evolution of such objects. Spectral line equivalent widths (EW) exhibit orbital phase dependent variations, indicating the probable contribution from the secondary. A period variation study of the object was carried out using times of minima obtained from the literature and suggesting a decrease in period. The evolutionary state of the system is evaluated and discussed.
TYC 3315-1807-1是由Kawka et al.(2010)首次报道的sdB+dM双星。存档的光度数据表明，存在一个次级伴星，造成了很大的反射效应。该天体的光谱观测是在卡瓦鲁的Vainu Bappu天文台进行的，目的是探测次级伴星的性质，并了解这类天体在共同包络层后的演化。谱线等效宽度(EW)表现出轨道相位相关的变化，表明可能来自次级的贡献。使用从文献中获得的最小值进行了对象的周期变化研究，并建议周期减少。对系统的演化状态进行了评价和讨论。
{"title":"A comprehensive study of the sdB+dM binary TYC 3315-1807-1","authors":"J. Rukmini, D. S. Priya, P. Jishnu, G. V. Kumar","doi":"10.31577/caosp.2020.50.2.627","DOIUrl":"https://doi.org/10.31577/caosp.2020.50.2.627","url":null,"abstract":"TYC 3315-1807-1 is an sdB+dM binary first reported by Kawka et al. (2010). Archival photometric data indicate the presence of a secondary companion causing a large reflection effect. Spectroscopic observations of the object were carried out from Vainu Bappu Observatory, Kavalur, to probe the nature of the secondary companion and to understand the post commonenvelope evolution of such objects. Spectral line equivalent widths (EW) exhibit orbital phase dependent variations, indicating the probable contribution from the secondary. A period variation study of the object was carried out using times of minima obtained from the literature and suggesting a decrease in period. The evolutionary state of the system is evaluated and discussed.","PeriodicalId":50617,"journal":{"name":"Contributions of the Astronomical Observatory Skalnate Pleso","volume":null,"pages":null},"PeriodicalIF":0.5,"publicationDate":"2020-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75743974","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-03-01DOI: 10.31577/caosp.2020.50.2.563
M. Fedurco, M. Cokina, S. Parimucha
We present an easy to use software package fully written in Python designed for light curve modelling of eclipsing close binaries. The software provides full treatment of the Roche geometry and irradiation effects utilizing symmetries of tidally deformed stellar surfaces and eccentric orbits in order to reduce overall computational time. Additionally, the software package allows modelling of spots and low-amplitude radial and non-radial pulsations.
{"title":"Light curve modelling of close eclipsing binaries","authors":"M. Fedurco, M. Cokina, S. Parimucha","doi":"10.31577/caosp.2020.50.2.563","DOIUrl":"https://doi.org/10.31577/caosp.2020.50.2.563","url":null,"abstract":"We present an easy to use software package fully written in Python designed for light curve modelling of eclipsing close binaries. The software provides full treatment of the Roche geometry and irradiation effects utilizing symmetries of tidally deformed stellar surfaces and eccentric orbits in order to reduce overall computational time. Additionally, the software package allows modelling of spots and low-amplitude radial and non-radial pulsations.","PeriodicalId":50617,"journal":{"name":"Contributions of the Astronomical Observatory Skalnate Pleso","volume":null,"pages":null},"PeriodicalIF":0.5,"publicationDate":"2020-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77285398","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-03-01DOI: 10.31577/caosp.2020.50.2.574
R. Griffin
Composite-spectrum binaries (containing a cool giant primary and a hot dwarf secondary) should be an answer to a theoretician’s prayer. Because of their luminosity difference, both spectra are visible in the near UV, a region that includes several valuable luminosity and temperature indicators. If we just measure the radial velocity (RV) of the secondary at different dates, and construct an SB2 orbit, we immediate get the mass ratio of the component stars. A guess of the mass of the dwarf, and one thence obtains the mass of the cool giant – a unique and immensely valuable method. But just measure a hot dwarf’s RV?? It raises many problems, mostly caused by the nature of the star. A hot (late-B or early-A) dwarf has few lines, most are weak, they can be very blurred by rotation, and they get hidden by the crowded spectra of the giant. Spectral subtraction works a treat in separating the two spectra, but the residue is inevitably rather noisy. Nevertheless, results from well over half of the 45 brightest northern composite-spectrum binaries have been published; about 1 in 6 are triple systems, and a few have characteristics that defy any theoretician to explain. Several are ‘bad’ because their giant primaries have high luminosity and finding a matching standard for the subtraction process is troublesome, while the ‘really ugly’ include an Am star in a simple SB2 binary with a period of 75 years, a pair of early-A dwarfs in a 3-day orbit with amplitudes of 100 km s−1 and which show absolutely no rotational broadening at all, and another whose secondary (apparently a single star) is more that twice as massive as its primary giant. But 8 of the sample are also eclipsing, and manifest the hugely important phenomenon of chromospheric absorption – those are the ‘really good’ systems. The talk showed examples of each kind.
{"title":"The good, the bad and the really ugly: composite-spectrum binaries","authors":"R. Griffin","doi":"10.31577/caosp.2020.50.2.574","DOIUrl":"https://doi.org/10.31577/caosp.2020.50.2.574","url":null,"abstract":"Composite-spectrum binaries (containing a cool giant primary and a hot dwarf secondary) should be an answer to a theoretician’s prayer. Because of their luminosity difference, both spectra are visible in the near UV, a region that includes several valuable luminosity and temperature indicators. If we just measure the radial velocity (RV) of the secondary at different dates, and construct an SB2 orbit, we immediate get the mass ratio of the component stars. A guess of the mass of the dwarf, and one thence obtains the mass of the cool giant – a unique and immensely valuable method. But just measure a hot dwarf’s RV?? It raises many problems, mostly caused by the nature of the star. A hot (late-B or early-A) dwarf has few lines, most are weak, they can be very blurred by rotation, and they get hidden by the crowded spectra of the giant. Spectral subtraction works a treat in separating the two spectra, but the residue is inevitably rather noisy. Nevertheless, results from well over half of the 45 brightest northern composite-spectrum binaries have been published; about 1 in 6 are triple systems, and a few have characteristics that defy any theoretician to explain. Several are ‘bad’ because their giant primaries have high luminosity and finding a matching standard for the subtraction process is troublesome, while the ‘really ugly’ include an Am star in a simple SB2 binary with a period of 75 years, a pair of early-A dwarfs in a 3-day orbit with amplitudes of 100 km s−1 and which show absolutely no rotational broadening at all, and another whose secondary (apparently a single star) is more that twice as massive as its primary giant. But 8 of the sample are also eclipsing, and manifest the hugely important phenomenon of chromospheric absorption – those are the ‘really good’ systems. The talk showed examples of each kind.","PeriodicalId":50617,"journal":{"name":"Contributions of the Astronomical Observatory Skalnate Pleso","volume":null,"pages":null},"PeriodicalIF":0.5,"publicationDate":"2020-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91184274","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-03-01DOI: 10.31577/caosp.2020.50.2.611
X. Zhou, B. Soonthornthum, S. Qian
Our RC and IC light curves of CSS J135012.1+272259 were analyzed with the Wilson-Devinney (W-D) program. The results reveal that CSS J135012.1+272259 is an extreme mass ratio overcontact binary with mass ratio q = 0.147. It may be in the final evolutionary stage of cool short-period binaries and merge into a single rapid-rotation star to form a blue straggler or FK Com type star. Also, 25 extreme mass ratio overcontact binary systems (q ≤ 0.15) are collected for long-term monitoring. These targets will improve understanding of the pre-outburst state of overcontact binaries and enrich knowledge of the merger mechanism.
{"title":"Photometric observations of an extreme mass ratio overcontact binary","authors":"X. Zhou, B. Soonthornthum, S. Qian","doi":"10.31577/caosp.2020.50.2.611","DOIUrl":"https://doi.org/10.31577/caosp.2020.50.2.611","url":null,"abstract":"Our RC and IC light curves of CSS J135012.1+272259 were analyzed with the Wilson-Devinney (W-D) program. The results reveal that CSS J135012.1+272259 is an extreme mass ratio overcontact binary with mass ratio q = 0.147. It may be in the final evolutionary stage of cool short-period binaries and merge into a single rapid-rotation star to form a blue straggler or FK Com type star. Also, 25 extreme mass ratio overcontact binary systems (q ≤ 0.15) are collected for long-term monitoring. These targets will improve understanding of the pre-outburst state of overcontact binaries and enrich knowledge of the merger mechanism.","PeriodicalId":50617,"journal":{"name":"Contributions of the Astronomical Observatory Skalnate Pleso","volume":null,"pages":null},"PeriodicalIF":0.5,"publicationDate":"2020-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83828027","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-03-01DOI: 10.31577/caosp.2020.50.2.521
S. Palafouta, K. Gazeas
The existence of magnetic activity on the eclipsing binary DV Psc has been known for almost two decades. However, until recently, no evidence of periodic behaviour relevant to this activity had been found. In this study, long-term photometric observations of DV Psc are used to analyze the system’s magnetic activity, seek a possible magnetic cycle and determine orbital and physical parameters. The combination of photometric and spectroscopic observations results in a unified model that describes the system over time in terms of variable spot activity. New times of minimum light are determined and an accurate astronomical ephemeris and updated O-C diagram are constructed for a total span of 19 years (1997-2017). The intense magnetic activity, as indicated by strong asymmetries in the light curves (O’ Connell effect), and the periodic variation of the O-C diagram are combined to explain the system’s behaviour. The existence of a third body, orbiting the eclipsing binary in an eccentric orbit, as well as a magnetic cycle are the most likely scenario.
{"title":"Temporal evolution of the magnetically active eclipsing binary DV Psc","authors":"S. Palafouta, K. Gazeas","doi":"10.31577/caosp.2020.50.2.521","DOIUrl":"https://doi.org/10.31577/caosp.2020.50.2.521","url":null,"abstract":"The existence of magnetic activity on the eclipsing binary DV Psc has been known for almost two decades. However, until recently, no evidence of periodic behaviour relevant to this activity had been found. In this study, long-term photometric observations of DV Psc are used to analyze the system’s magnetic activity, seek a possible magnetic cycle and determine orbital and physical parameters. The combination of photometric and spectroscopic observations results in a unified model that describes the system over time in terms of variable spot activity. New times of minimum light are determined and an accurate astronomical ephemeris and updated O-C diagram are constructed for a total span of 19 years (1997-2017). The intense magnetic activity, as indicated by strong asymmetries in the light curves (O’ Connell effect), and the periodic variation of the O-C diagram are combined to explain the system’s behaviour. The existence of a third body, orbiting the eclipsing binary in an eccentric orbit, as well as a magnetic cycle are the most likely scenario.","PeriodicalId":50617,"journal":{"name":"Contributions of the Astronomical Observatory Skalnate Pleso","volume":null,"pages":null},"PeriodicalIF":0.5,"publicationDate":"2020-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88412480","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-03-01DOI: 10.31577/caosp.2020.50.2.495
K. Gazeas
W Ursae Majoris-type binaries belong to the old population of our Galaxy, while their metallicity is close to solar. Their physical properties, kinematics and spatial distribution reflect the properties of their stellar progenitors. This study focuses on the spatial distribution of W UMa’s in our solar neighborhood within a 500 pc radius, with a combined astrometric, photometric and spectroscopic determination of their stellar parameters. The sample is carefully selected, in order to fulfill certain criteria, and has well defined metallicity and distance parameters. H-R diagram, as well as similar correlation plots (mass-radius and mass-luminosity), show that the primary (more massive) components in such systems are located close or below the ZAMS region, while secondary components seem to be evolved, as a result of their common envelope geometry. Some prominent outliers are carefully examined in order to judge the environmental properties and evolution in certain locations of the Milky Way. It is found that metallicity is not correlated with distance, but there is a weak correlation between metallicity [M/H] and evolution state, as it is expressed by the location of the systems in the H-R diagram, the type of binary (A or W), and temperature.
{"title":"The population of W Ursae Majoris-type binaries in the solar neighborhood","authors":"K. Gazeas","doi":"10.31577/caosp.2020.50.2.495","DOIUrl":"https://doi.org/10.31577/caosp.2020.50.2.495","url":null,"abstract":"W Ursae Majoris-type binaries belong to the old population of our Galaxy, while their metallicity is close to solar. Their physical properties, kinematics and spatial distribution reflect the properties of their stellar progenitors. This study focuses on the spatial distribution of W UMa’s in our solar neighborhood within a 500 pc radius, with a combined astrometric, photometric and spectroscopic determination of their stellar parameters. The sample is carefully selected, in order to fulfill certain criteria, and has well defined metallicity and distance parameters. H-R diagram, as well as similar correlation plots (mass-radius and mass-luminosity), show that the primary (more massive) components in such systems are located close or below the ZAMS region, while secondary components seem to be evolved, as a result of their common envelope geometry. Some prominent outliers are carefully examined in order to judge the environmental properties and evolution in certain locations of the Milky Way. It is found that metallicity is not correlated with distance, but there is a weak correlation between metallicity [M/H] and evolution state, as it is expressed by the location of the systems in the H-R diagram, the type of binary (A or W), and temperature.","PeriodicalId":50617,"journal":{"name":"Contributions of the Astronomical Observatory Skalnate Pleso","volume":null,"pages":null},"PeriodicalIF":0.5,"publicationDate":"2020-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84176623","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-03-01DOI: 10.31577/caosp.2020.50.2.552
R. E. Wilson, W. Hamme, G. Peters
Strategies are introduced for coherent measurement of pulsational waveforms, amplitudes, periods, and period change rates, where ‘coherent’ means that the model stars indeed pulsate, with no artificial alternation between pulsation without binary effects and binary effects without pulsation. Capabilities of the more advanced eclipsing binary (EB) light curve models are in place, such as simultaneous solutions of multiband data and radial velocities with inclusion of tides, mutual irradiation, and proper datapoint weighting. An application to the Algol-type EB V1352 Tau exhibits possibilities.
{"title":"Binary star analysis with intrinsic pulsation","authors":"R. E. Wilson, W. Hamme, G. Peters","doi":"10.31577/caosp.2020.50.2.552","DOIUrl":"https://doi.org/10.31577/caosp.2020.50.2.552","url":null,"abstract":"Strategies are introduced for coherent measurement of pulsational waveforms, amplitudes, periods, and period change rates, where ‘coherent’ means that the model stars indeed pulsate, with no artificial alternation between pulsation without binary effects and binary effects without pulsation. Capabilities of the more advanced eclipsing binary (EB) light curve models are in place, such as simultaneous solutions of multiband data and radial velocities with inclusion of tides, mutual irradiation, and proper datapoint weighting. An application to the Algol-type EB V1352 Tau exhibits possibilities.","PeriodicalId":50617,"journal":{"name":"Contributions of the Astronomical Observatory Skalnate Pleso","volume":null,"pages":null},"PeriodicalIF":0.5,"publicationDate":"2020-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73032886","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-03-01DOI: 10.31577/caosp.2020.50.2.570
E. Paunzen
Magnetic chemically peculiar stars of the upper main sequence are slowly rotating early B to early F-type objects with elemental overabundances of several orders of magnitude compared to the Sun. The driving mechanism is diffusion in the calm stellar atmosphere intensified by the presence of a stable organized magnetic field. The binary fraction is vital to understanding the formation and evolution of these objects as well as possible operating angular momentum loss mechanisms. The available literature on the binary fraction is reviewed and a list of needed future working steps is presented.
{"title":"Binary fraction of magnetic chemically peculiar stars","authors":"E. Paunzen","doi":"10.31577/caosp.2020.50.2.570","DOIUrl":"https://doi.org/10.31577/caosp.2020.50.2.570","url":null,"abstract":"Magnetic chemically peculiar stars of the upper main sequence are slowly rotating early B to early F-type objects with elemental overabundances of several orders of magnitude compared to the Sun. The driving mechanism is diffusion in the calm stellar atmosphere intensified by the presence of a stable organized magnetic field. The binary fraction is vital to understanding the formation and evolution of these objects as well as possible operating angular momentum loss mechanisms. The available literature on the binary fraction is reviewed and a list of needed future working steps is presented.","PeriodicalId":50617,"journal":{"name":"Contributions of the Astronomical Observatory Skalnate Pleso","volume":null,"pages":null},"PeriodicalIF":0.5,"publicationDate":"2020-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74276920","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-03-01DOI: 10.31577/caosp.2020.50.2.546
P. Németh
The formation of hot subdwarf stars (sdB) is closely related to binary evolution on the red giant branch. Observations show that hot subdwarfs are either in close binaries with low mass K-M type or white dwarf companions, or in wide binaries with more massive F-G type companions. A small fraction is most strikingly single. In close binaries the radiative interactions give rise to the reflection effect and produces a variable composite spectrum. More massive companions bear similar optical luminosities as sdB stars and therefore double-lined spectra are observed. To investigate such systems in detail and precision spectral decomposition/disentangling is needed. I describe our wavelength space disentangling method and bring examples why such an approach to composite spectra offers a potential to find the history of hot subdwarfs.
{"title":"Composite spectrum hot subdwarf binaries","authors":"P. Németh","doi":"10.31577/caosp.2020.50.2.546","DOIUrl":"https://doi.org/10.31577/caosp.2020.50.2.546","url":null,"abstract":"The formation of hot subdwarf stars (sdB) is closely related to binary evolution on the red giant branch. Observations show that hot subdwarfs are either in close binaries with low mass K-M type or white dwarf companions, or in wide binaries with more massive F-G type companions. A small fraction is most strikingly single. In close binaries the radiative interactions give rise to the reflection effect and produces a variable composite spectrum. More massive companions bear similar optical luminosities as sdB stars and therefore double-lined spectra are observed. To investigate such systems in detail and precision spectral decomposition/disentangling is needed. I describe our wavelength space disentangling method and bring examples why such an approach to composite spectra offers a potential to find the history of hot subdwarfs.","PeriodicalId":50617,"journal":{"name":"Contributions of the Astronomical Observatory Skalnate Pleso","volume":null,"pages":null},"PeriodicalIF":0.5,"publicationDate":"2020-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82153346","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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