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High Spatial Resolution X-Ray Spectroscopy of Cas A with Chandra 钱德拉Cas A的高空间分辨率x射线光谱
Chinese Journal of Astronomy and Astrophysics Pub Date : 2007-12-07 DOI: 10.1088/1009-9271/8/4/08
Xue-juan Yang, F. Lu, Li Chen
{"title":"High Spatial Resolution X-Ray Spectroscopy of Cas A with Chandra","authors":"Xue-juan Yang, F. Lu, Li Chen","doi":"10.1088/1009-9271/8/4/08","DOIUrl":"https://doi.org/10.1088/1009-9271/8/4/08","url":null,"abstract":"We present high spatial resolution X-ray spectroscopy of the supernova remnant Cassiopeia A with the Chandra observations. The X-ray emitting region of this remnant was divided into 38 × 34 pixels of 10''× 10'' each. Spectra of 960 pixels were created and fitted with an absorbed two component non-equilibrium ionization model. From the results of the spectral analysis we obtained maps of absorbing column density, temperatures, ionization ages, and the abundances of Ne, Mg, Si, S, Ca and Fe. The Si, S and possibly Ca abundance maps show obvious jet structures, while Fe does not follow the jet but seems to be distributed perpendicular to it. The abundances of Si, S and Ca show tight correlations between one another over a range of about two dex. This suggests that they are ejecta from explosive O-burning and incomplete Si-burning. Meanwhile, the Ne abundance is well correlated with that of Mg, indicating them to be the ashes of explosive C/Ne burning. The Fe abundance is positively correlated with that of Si when the latter is lower than 3 times the solar value, and is negatively correlated when higher. We suggest that such a two phase correlation is due to the different ways in which Fe was synthesized.","PeriodicalId":124495,"journal":{"name":"Chinese Journal of Astronomy and Astrophysics","volume":"41 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2007-12-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116962743","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: 12
Are Seyfert 2 Galaxies without Polarized Broad Emission Lines More Obscured 没有偏振宽发射线的塞弗特2星系更模糊吗
Chinese Journal of Astronomy and Astrophysics Pub Date : 2007-12-03 DOI: 10.1088/1009-9271/8/2/07
Xinwen Shu, Junxian Wang, P. Jiang
{"title":"Are Seyfert 2 Galaxies without Polarized Broad Emission Lines More Obscured","authors":"Xinwen Shu, Junxian Wang, P. Jiang","doi":"10.1088/1009-9271/8/2/07","DOIUrl":"https://doi.org/10.1088/1009-9271/8/2/07","url":null,"abstract":"New XMM-Newton data of seven Seyfert 2 galaxies with optical spectropolarimetric observations are presented. An analysis of the 0.5–10 keV spectra shows that four Seyfert 2 galaxies with polarized broad lines (PBLs) are absorbed by NH<1024 cm−2, while two of three Seyfert 2 galaxies without PBLs show evidence of Compton-thick obscuration, supporting the conclusion that Seyfert 2 galaxies without PBLs are more obscured than those with PBLs. Adding the measured obscuration indicators (NH, T ratio, and Fe Kα line EW) of six luminous AGNs to our previous sample improves the significance level of the difference in absorption from 92.3% to 96.3% for NH, 99.1% to 99.4% for T ratio, and 95.3% to 97.4% for Fe Kα line EW. The present results support and enhance the suggestions that the absence of PBLs in Seyfert 2 galaxies can be explained by larger viewing angles of the line of sight to the putative dusty torus, which leads to the obscuration of the broad-line scattering screen, as expected in the unification model.","PeriodicalId":124495,"journal":{"name":"Chinese Journal of Astronomy and Astrophysics","volume":"52 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2007-12-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130769566","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: 9
Short-Term Period Variation of Relative Sunspot Numbers 相对太阳黑子数的短期变化
Chinese Journal of Astronomy and Astrophysics Pub Date : 2007-12-01 DOI: 10.1088/1009-9271/7/6/10
Z. Yin, Yan-ben Han, Lihua Ma, G. Le, Yonggang Han
{"title":"Short-Term Period Variation of Relative Sunspot Numbers","authors":"Z. Yin, Yan-ben Han, Lihua Ma, G. Le, Yonggang Han","doi":"10.1088/1009-9271/7/6/10","DOIUrl":"https://doi.org/10.1088/1009-9271/7/6/10","url":null,"abstract":"We use wavelet transform to analyze the daily relative sunspot number series over solar cycles 10–23. The characteristics of some of the periods shorter than ~600-day are discussed. The results exhibit not only the variation of some short periods in the 14 solar cycles but also the characteristics and differences around solar peaks and valley years. The short periodic components with larger amplitude such as ~27, ~150 and ~360-day are obvious in some solar cycles, all of them are time-variable, also their lengths and amplitudes are variable and intermittent in time. The variable characteristics of the periods are rather different in different solar cycles.","PeriodicalId":124495,"journal":{"name":"Chinese Journal of Astronomy and Astrophysics","volume":"18 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2007-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129980944","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: 16
Variable Star Status of Two Stars: V204 and I-I-39 in M3 两颗星的变星状态:M3中的V204和I-I-39
Chinese Journal of Astronomy and Astrophysics Pub Date : 2007-12-01 DOI: 10.1088/1009-9271/7/6/04
B. Yao
{"title":"Variable Star Status of Two Stars: V204 and I-I-39 in M3","authors":"B. Yao","doi":"10.1088/1009-9271/7/6/04","DOIUrl":"https://doi.org/10.1088/1009-9271/7/6/04","url":null,"abstract":"The star I-I-42 (=vZ1390), a cluster member in M3, located near the red edge of the instability strip of the horizontal branch, was discovered by Roberts and Sandage as a low amplitude variable, it was designated as V204 in the \"second catalogue of variable stars in globular clusters\", but its coordinates given in all versions of this catalogue are wrong since 1955. We argue that V204 is indeed a low amplitude HB variable star, located near to the red edge of the instability strip, with a period of 0.74785(d) and an amplitude of about 0.04 mag in V. We also find that the red cluster member star I-I-39 is a low amplitude variable with a period of 1.16(d) and amplitude of about 0.03 mag in V which might be pulsating at the second overtone.","PeriodicalId":124495,"journal":{"name":"Chinese Journal of Astronomy and Astrophysics","volume":"45 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2007-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127915889","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
Radio Phase-Resolved Spectra of the Conal-Double Pulsar B1133+16 ∗ 锥形双脉冲星B1133+16 *的无线电相位分辨光谱
Chinese Journal of Astronomy and Astrophysics Pub Date : 2007-12-01 DOI: 10.1088/1009-9271/7/6/06
Jian-Ling Chen, Hong-Guang Wang, Wanghua Chen, Hui Zhang, Yi Liu
{"title":"Radio Phase-Resolved Spectra of the Conal-Double Pulsar B1133+16 ∗","authors":"Jian-Ling Chen, Hong-Guang Wang, Wanghua Chen, Hui Zhang, Yi Liu","doi":"10.1088/1009-9271/7/6/06","DOIUrl":"https://doi.org/10.1088/1009-9271/7/6/06","url":null,"abstract":"Based on dividing the profile into a number of absolute phase intervals, the phase-resolved spectra (PHRS) are derived from published time-aligned average profiles at radio frequencies over two decades for the classic conal-double pulsar B1133+16. The relative spectral index, defined as the difference between the spectral indices of a reference and the given arbitrary phase interval, is obtained by power-law fit at each phase interval. The derived phase-resolved spectra show an ``M-like'' shape, of which the leading part and trailing part are approximately symmetrical. The basic feature of the PHRS is that the spectrum first flattens then steepens as the pulse phase sweeps from the profile center to the profile edges. The PHRS provide a coherent explanation of the major features of profile evolution of B1133+16, namely, the pulse width shrinkage with increasing frequency and the frequency evolution of the relative intensity between the leading and trailing conal components, and the bridge emission. The PHRS may be an indicator for emission spectral variation across the pulsar magnetosphere. Possible mapping from PHRS to emission-location-dependent spectral variation is presented, and some intrinsic mechanisms are discussed.","PeriodicalId":124495,"journal":{"name":"Chinese Journal of Astronomy and Astrophysics","volume":"116 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2007-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132225001","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: 6
Simulation study on high energy cosmic electron detection by shower image 星雨图像高能宇宙电子探测的模拟研究
Chinese Journal of Astronomy and Astrophysics Pub Date : 2007-12-01 DOI: 10.1088/1009-9271/7/6/12
R. Xu, J. Chang, S. Torii, K. Kasahara, T. Tamura, K. Yoshida
{"title":"Simulation study on high energy cosmic electron detection by shower image","authors":"R. Xu, J. Chang, S. Torii, K. Kasahara, T. Tamura, K. Yoshida","doi":"10.1088/1009-9271/7/6/12","DOIUrl":"https://doi.org/10.1088/1009-9271/7/6/12","url":null,"abstract":"Many projects have recently been carried out and proposed for observing high energy electrons since it is realized that cosmic ray electrons are very important when studying the dark matter particles and the acceleration mechanism of cosmic rays. An imaging calorimeter, BETS (Balloon-borne Electron Telescope with Scintillator fiber), has been developed for this purpose. Using pattern analysis of the shower development, the electrons can be selected from those primary cosmic ray proton events with flux heights one-tenth that of the electrons. The Monte-Carlo simulation is indispensable for the instrument design, the signal trigger and the data analysis. We present different shower simulation codes and compare the simulation results with the beam test and the flight data of BETS. We conclude that the code FLUKA2002 gives the most consistent results with the experimental data.","PeriodicalId":124495,"journal":{"name":"Chinese Journal of Astronomy and Astrophysics","volume":"403 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2007-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133610816","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
Generation of Interstellar Class II 72-81A + and 72-81A − Methanol Masers ∗ 星际II类72-81A +和72-81A−甲醇激射器的产生
Chinese Journal of Astronomy and Astrophysics Pub Date : 2007-12-01 DOI: 10.1088/1009-9271/7/6/07
Hanping Liu, Jin Sun
{"title":"Generation of Interstellar Class II 72-81A + and 72-81A − Methanol Masers ∗","authors":"Hanping Liu, Jin Sun","doi":"10.1088/1009-9271/7/6/07","DOIUrl":"https://doi.org/10.1088/1009-9271/7/6/07","url":null,"abstract":"New methanol maser lines at 72?63A?(86.6 GHz) and 72?63A+(86.9 GHz) together with two candidate methanol maser lines at 72?81A?(80.99 GHz) and 72?81A+(111.29 GHz) have been detected in W3(OH). We use a pumping mechanism, i.e., methanol masers without population inversion, to explain the formation of weak methanol masers of 72?81A+ and 72?81A?. We explain well why the line-shape of the transition 72?81A+ is not typical. A similar argument can be applied to the ?-type level system 72A?, 63A? and 81A?, as well as to the 72?81A? 80.99 GHz masers.","PeriodicalId":124495,"journal":{"name":"Chinese Journal of Astronomy and Astrophysics","volume":"36 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2007-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131931426","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
A New Formulation for General Relativistic Force-Free Electrodynamics and Its Applications 广义相对论无力电动力学的新公式及其应用
Chinese Journal of Astronomy and Astrophysics Pub Date : 2007-12-01 DOI: 10.1088/1009-9271/7/6/01
Cong Yu
{"title":"A New Formulation for General Relativistic Force-Free Electrodynamics and Its Applications","authors":"Cong Yu","doi":"10.1088/1009-9271/7/6/01","DOIUrl":"https://doi.org/10.1088/1009-9271/7/6/01","url":null,"abstract":"We formulate the general relativistic force-free electrodynamics in a new 3 + 1 language. In this formulation, when we have properly defined electric and magnetic fields, the covariant Maxwell equations could be cast in the traditional form with new vacuum constitutive constraint equations. The fundamental equation governing a stationary, axisymmetric force-free black hole magnetosphere is derived using this formulation which recasts the Grad-Shafranov equation in a simpler way. Compared to the classic 3+1 system of Thorne and MacDonald, the new system of 3+1 equations is more suitable for numerical use for it keeps the hyperbolic structure of the electrodynamics and avoids the singularity at the event horizon. This formulation could be readily extended to non-relativistic limit and find applications in flat spacetime. We investigate its application to disk wind, black hole magnetosphere and solar physics in both flat and curved spacetime.","PeriodicalId":124495,"journal":{"name":"Chinese Journal of Astronomy and Astrophysics","volume":"16 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2007-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125906907","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: 1
A Study of the Star-forming Dwarf Galaxy NGC 855 with Spitzer 用斯皮策研究形成恒星的矮星系NGC 855
Chinese Journal of Astronomy and Astrophysics Pub Date : 2007-12-01 DOI: 10.1088/1009-9271/7/6/03
Shen Li, Q. Gu, Yinghe Zhao, Jia-Sheng Huang, Xin-Lian Luo
{"title":"A Study of the Star-forming Dwarf Galaxy NGC 855 with Spitzer","authors":"Shen Li, Q. Gu, Yinghe Zhao, Jia-Sheng Huang, Xin-Lian Luo","doi":"10.1088/1009-9271/7/6/03","DOIUrl":"https://doi.org/10.1088/1009-9271/7/6/03","url":null,"abstract":"We present a study of the dwarf elliptical galaxy NGC 855 using the narrow-band Hα and Spitzer data. Both the Hα and Spitzer IRAC images confirm star-forming activity in the center of NGC 855. We obtained a star formation rate (SFR) of 0.022 and 0.025M⊙ yr−1, respectively, from the Spitzer IRAC 8.0 μm and MIPS 24 μm emission data. The HI observation suggests that the star-forming activity might be triggered by a minor merger. We also find that there is a distinct IR emission region in 5.8 and 8.0 μm bands, located at about 10'' away from the nucleus of NGC 855. Given the strong 8.0 μm but faint Hα emission, we expect that it is a heavily obscured star-forming region, which needs to be confirmed by further optical spectroscopic observations.","PeriodicalId":124495,"journal":{"name":"Chinese Journal of Astronomy and Astrophysics","volume":"238 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2007-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133932274","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: 1
An Alternative Explanation for a Screw-like Meteoric Train Photographed by Double-Station Observations 双站观测拍摄的螺旋状流星列车的另一种解释
Chinese Journal of Astronomy and Astrophysics Pub Date : 2007-12-01 DOI: 10.1088/1009-9271/7/6/09
Guang-jie Wu
{"title":"An Alternative Explanation for a Screw-like Meteoric Train Photographed by Double-Station Observations","authors":"Guang-jie Wu","doi":"10.1088/1009-9271/7/6/09","DOIUrl":"https://doi.org/10.1088/1009-9271/7/6/09","url":null,"abstract":"Two-station observation of meteors, especially a meteor trains, provides an effective approach to the measurement of the physical parameters. We have collected four special groups of photographs of meteoric trains taken at two stations during Leonids 2001. One representative group has been measured and analyzed in detail. An analysis has been reported in our first paper. In this paper, an alternative explanation for the screw-like meteoric train is suggested based on some physical calculations. The results reveal that this train has a screw-like structure and, apparently, spoke beams. The mother meteor of this train may be negatively charged and moves forward along a left-hand screw trajectory under the effect of the geomagnetic field. The spoke beams might be the visual effect of the long time exposure of many particles released from the disintegrated meteoroid.","PeriodicalId":124495,"journal":{"name":"Chinese Journal of Astronomy and Astrophysics","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2007-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121057726","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
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