Chinese Journal of Astronomy and Astrophysics最新文献_第4页

Formation of Transient Coronal Holes during the Eruption of a Quiescent Filament and its Overlying Sigmoid 静止灯丝及其上覆的乙状星爆发期间瞬态日冕洞的形成

Chinese Journal of Astronomy and Astrophysics Pub Date : 2008-06-01 DOI: 10.1088/1009-9271/8/3/09

Liheng Yang, Yunchun Jiang, D. Ren

{"title":"Formation of Transient Coronal Holes during the Eruption of a Quiescent Filament and its Overlying Sigmoid","authors":"Liheng Yang, Yunchun Jiang, D. Ren","doi":"10.1088/1009-9271/8/3/09","DOIUrl":"https://doi.org/10.1088/1009-9271/8/3/09","url":null,"abstract":"By using Ha, He 110830, EUV and soft X-ray (SXR) data, we examined a filament eruption that occurred on a quiet-sun region near the center of the solar disk on 2006 January 12, which disturbed a sigmoid overlying the filament channel observed by the GOES-12 SXR Imager (SXI), and led to the eruption of the sigmoid. The event was associated with a partial halo coronal mass ejection (CME) observed by the Large Angle and Spectrometric Coronagraphs (LASCO) on board the Solar and Heliospheric Observatory (SOHO), and resulted in the formation of two flare-like ribbons, post-eruption coronal loops, and two transient coronal holes (TCHs), but there were no significantly recorded GOES or Ha flares corresponding to the eruption. The two TCHs were dominated by opposite magnetic polarities and were located on the two ends of the eruptive sigmoid. They showed similar locations and shapes in He I 10830, EUV and SXR observations. During the early eruption phase, brightenings first appeared on the locations of the two subsequent TCHs, which could be clearly identified on He I 10830, EUV and SXR images. This eruption could be explained by the magnetic flux rope model, and the two TCHs were likely to be the feet of the flux rope.","PeriodicalId":124495,"journal":{"name":"Chinese Journal of Astronomy and Astrophysics","volume":"9 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114695603","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: 7

Swift/BAT Observations of X-Ray Flashes 快速/BAT对x射线闪光的观测

Chinese Journal of Astronomy and Astrophysics Pub Date : 2008-06-01 DOI: 10.1088/1009-9271/8/3/07

Yi-qing Lin

引用次数: 0

Long-Term Sunspot Number Prediction based on EMD Analysis and AR Model 基于EMD分析和AR模型的长期太阳黑子数预测

Chinese Journal of Astronomy and Astrophysics Pub Date : 2008-06-01 DOI: 10.1088/1009-9271/8/3/10

T. Xu, Jian Wu, Zhensen Wu, Qiang Li

引用次数: 41

Improving the Angular Resolution of Coded-Mask Telescopes by Direct Demodulation 直接解调提高编码掩模望远镜的角分辨率

Chinese Journal of Astronomy and Astrophysics Pub Date : 2008-06-01 DOI: 10.1088/1009-9271/8/3/11

Z. Shen, Jian-feng Zhou

引用次数: 2

The Structure of Narrow-Line Region in LINERs 班轮窄线区域的结构

Chinese Journal of Astronomy and Astrophysics Pub Date : 2008-06-01 DOI: 10.1088/1009-9271/8/3/01

H. Dai, Ting-gui Wang

{"title":"The Structure of Narrow-Line Region in LINERs","authors":"H. Dai, Ting-gui Wang","doi":"10.1088/1009-9271/8/3/01","DOIUrl":"https://doi.org/10.1088/1009-9271/8/3/01","url":null,"abstract":"Low-ionization nuclear emission regions (LINERs) are present in a large fraction of local galaxies, while their connection to the more luminous active galactic nuclei (AGN) remainselusive.We analyzethe narrowbandimagesobtainedby the HubbleSpace Telescope (HST )i n Hα+(NII) and/or (OIII) band for 23 LINERs and low luminosity Seyfert galaxies in the sample of the Palomar Optical Spectroscopic Survey of nearby galaxies in an attempt to resolve the structure of Narrow Emission Line Regions (NLRs) of these objects. In all cases, NLRs are well resolved and their morphology differs from object to object. Clumps, linear structure, spiral arms or a ring are detected in a large fraction of the objects, while there is no significant difference between Seyfert galaxies and LINERs. We find that the NLR size and the narrow line luminosity are strongly correlated for both LINERs and low luminosity Seyfert galaxies, and that the size of Hα+(NII) emission line region scales with Hα luminos- ity as RNLR ∝ L 0.44±0.06 Hα , consistent with an extension of the NLR size-luminosity relation defined for luminous Seyfert galaxies and quasars, to two orders of magnitude lower in lumi- nosity and to lower activity levels. Our results suggest that NLRs in LINERs are similar to those of Seyfert galaxies, and they are powered by the central active galactic nucleus.","PeriodicalId":124495,"journal":{"name":"Chinese Journal of Astronomy and Astrophysics","volume":"26 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127870394","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: 4

Optical Design of Multilayer Achromatic Waveplate by Simulated Annealing Algorithm 多层消色差波片的模拟退火光学设计

Chinese Journal of Astronomy and Astrophysics Pub Date : 2008-06-01 DOI: 10.1088/1009-9271/8/3/12

Jun Ma, Jing-Sheng Wang, C. Denker, Haimin Wang

引用次数: 22

Effects of α-Enhancement on Stellar Evolution α-增强对恒星演化的影响

Chinese Journal of Astronomy and Astrophysics Pub Date : 2008-06-01 DOI: 10.1088/1009-9271/8/3/03

Jianpo Guo, Fenghui Zhang, Xuefei Chen, Zhanwen Han

引用次数: 8

Observations of Giant Pulses of the Crab Pulsar 蟹状脉冲星巨脉冲的观测

Chinese Journal of Astronomy and Astrophysics Pub Date : 2008-06-01 DOI: 10.1088/1009-9271/8/3/05

Lingjie Kong, A. Esamdin, Cheng-shi Zhao, Zhiyong Liu, J. Yuan

引用次数: 1

Correlated Radio-Optical Variations on Intraday Timescales 日内时间尺度的相关射电-光学变化

Chinese Journal of Astronomy and Astrophysics Pub Date : 2008-04-20 DOI: 10.1088/1009-9271/8/2/09

S. Qian

{"title":"Correlated Radio-Optical Variations on Intraday Timescales","authors":"S. Qian","doi":"10.1088/1009-9271/8/2/09","DOIUrl":"https://doi.org/10.1088/1009-9271/8/2/09","url":null,"abstract":"Correlated radio-optical variations on intraday timescales have been observed (e.g. in BLO 0716+714) and such radio intraday variability is suggested to have an intrinsic origin. Recently, multi-wavelength observations, simultaneous at radio, mm-submm, optical and hard X-rays, of 0716+714, show that during a period of intraday/interday variations at radio and mm wavelengths, the apparent brightness temperature of the source exceeded the Compton-limit (~1012 K) by 2–4 orders of magnitude, but no Compton catastrophe (or no high luminosity of inverse-Compton radiation) was detected. It is also found that the intraday/interday variations at mm-submm wavelengths are consistent with the evolutionary behavior of a standard synchrotron source and for the intraday/interday variations at centimeter wavelengths opacity effects can play a significant role, which is consistent with the interpretation suggested previously by Qian et al. Thus the apparent high brightness temperatures may probably be explained in terms of Doppler boosting effects due to bulk relativistic motion of the source. We will argue a scenario to simulate the correlations between the radio and optical variations on intraday timescales observed in BLO 0716+714 in terms of a relativistic shock propagating through a jet with a dual structure.","PeriodicalId":124495,"journal":{"name":"Chinese Journal of Astronomy and Astrophysics","volume":"15 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-04-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131675092","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

Clustering Property of Wolf-Rayet Galaxies in the SDSS SDSS中Wolf-Rayet星系的聚类性质

Chinese Journal of Astronomy and Astrophysics Pub Date : 2008-04-01 DOI: 10.1088/1009-9271/8/2/08

Wei Zhang, X. Kong, F. Cheng

{"title":"Clustering Property of Wolf-Rayet Galaxies in the SDSS","authors":"Wei Zhang, X. Kong, F. Cheng","doi":"10.1088/1009-9271/8/2/08","DOIUrl":"https://doi.org/10.1088/1009-9271/8/2/08","url":null,"abstract":"We have analysed, for the first time, the clustering properties of Wolf-Rayet (W-R) galaxies, using a large sample of 846 W-R galaxies selected from the Data Release 4 (DR4) of the Sloan Digital Sky Survey (SDSS). We compute the cross-correlation function between W-R galaxies and a reference sample of galaxies drawn from the DR4. We compare the function to the results for control samples of non-W-R star-forming galaxies that are matched closely in redshift, luminosity, concentration, 4000-A break strength and specific star formation rate (SSFR). On scales larger than a few Mpc, W-R galaxies have almost the same clustering amplitude as the control samples, indicating that W-R galaxies and non-W-R control galaxies populate dark matter haloes of similar masses. On scales between 0.1–1h−1 Mpc, W-R galaxies are less clustered than the control samples, and the size of the difference depends on the SSFR. Based on both observational and theoretical considerations, we speculate that this negative bias can be interpreted by W-R galaxies residing preferentially at the centers of their dark matter haloes. We examine the distribution of W-R galaxies more closely using the SDSS galaxy group catalogue of Yang et al., and find that ~82% of our W-R galaxies are the central galaxies of groups, compared to ~74% for the corresponding control galaxies. We find that W-R galaxies are hosted, on average, by dark matter haloes of masses of 1012.3M⊙, compared to 1012.1M⊙ for centrally-located W-R galaxies and 1012.7M⊙ for satellite ones. We would like to point out that this finding, which provides a direct observational support to our conjecture, is really very crude due to the small number of W-R galaxies and the incompleteness of the group catalogue, and needs more work in future with larger samples.","PeriodicalId":124495,"journal":{"name":"Chinese Journal of Astronomy and Astrophysics","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128196207","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