天大噎记录的天文年代分析     

刘次沅 《时间频率学报》2005,28(2):145-154

古本《竹书纪年》记载有：“周昭王十九年，天大噎，雉兔皆震，丧六师于汉。”这与阴天发生的日全食现象十分相似。事件发生在昭王末年南征荆楚的过程中，地点应当在从周都到洞庭湖以南之间的某处。由前人的研究可知昭王十九年应在公元前1010。940年之间。在充分讨论了天文计算的不确定性后得到这一地区可见的9次大食分日食，其中公元前1009和976年的两次日食可能在洞庭湖以南造成日全食，其他地点也都有相当大的食分。在对夏商周断代工程得到的西周年表作微小调整后，昭王十九年天大睦可以认定为公元前976年5月31日日全食。这对“夏商周断代工程”所定出的昭王前后年代是一个独立的支持。  相似文献   

Radar observations of the Arietids     

M. D. Campbell-Brown 《Monthly notices of the Royal Astronomical Society》2004,352(4):1421-1425

  相似文献   

Dynamics and radiation of young type-Ia supernova remnants: Important physical processes     

Sorokina  E. I.  Blinnikov  S. I.  Kosenko  D. I.  Lundqvist  P. 《Astronomy Letters》2004,30(11):737-750

Astronomy Letters - We analyze the physical processes that should be taken into account when modeling young type-Ia supernova remnants (SNRs) with ages of several hundred years in which forward...  相似文献   

中国古代太阳中天观测及二至点测算精度   总被引：1，自引：0，他引：1  

李勇 《天文学进展》2005,23(1):70-79

研究了元代《授时历议))所保存的天象观测和推步资料，得出：(1)在AD1277—1280年问所作的98次太阳中天观测的时刻及地平高度的绝对值平均误差分别为2．64min和6．78′．(2)6部古历——《大衍历》、《宣明历》、《纪元历》、《统天历》、《重修大明历》和《授时历》推步BC522年前的3个冬至时刻的误差范围为0．97—3．51d；而AD435—1280年间的45个冬至时刻的绝对值平均误差则分别为9．35、10．42、5．54、2．97、5．68、3．36h．(3)古代确定的AD442—1280年间的16个二至时刻的绝对值平均误差为199．59min，其中元代的误差为27．89min．  相似文献   

用50m射电望远镜作脉冲星观测与研究     

康连生 《天文研究与技术》2004,1(3):176-187

国家天文台正在研制的50m射电望远镜将投入脉冲星观测与研究，推动我国的脉冲星工作。本文回顾了自第1颗脉冲星发现后35年来脉冲星观测取得的成果，和理论研究获得的重大进展，并讨论我国脉冲星工作可能开展的观测与研究。当今世界脉冲星观测与研究虽然还有许多遗留问题，但是作为中子星基本观测事实已被确认。脉冲星的应用也已经走上了历史舞台。如果利用50m射电望远镜对脉冲星的特殊活动现象进行观测与研究，可能获得突破性的进展。  相似文献   

Eagle Nebula Pillars: From Models to Observations     

Marc W. Pound  Jave O. Kane  Bruce A. Remington  Dmitri D. Ryutov  Akira Mizuta  Hideaki Takabe 《Astrophysics and Space Science》2005,298(1-2):177-181

Over the past few years, our group has been developing hydrodynamic models to simulate formation of the Eagle Nebula pillars. The true test of any model is, of course, how well it can reproduce the observations. Here, we discuss how we go about testing our models against observations. We describe the process by which we “observe” the model data to create synthetic maps. We show an example of this technique using one of our model runs and compare the resultant synthetic map to the real one.  相似文献   

The Allen Telescope Array     

David Deboer  Rob Ackermann  Leo Blitz  Douglas Bock  Geoffrey Bower  Michael Davis  John Dreher  Greg Engargiola  Matt Fleming  Girmay Keleta  Gerry Harp  John Lugten  Jill Tarter  Doug Thornton  Niklas Wadefalk  Sander Weinreb  William J. Welch 《Experimental Astronomy》2004,17(1-3):19-34

  相似文献   

Wavelet imaging cleaning method for atmospheric Cherenkov telescopes     

R. W. Lessard  L. Cayn  G. H. Sembroski  J. A. Gaidos 《Astroparticle Physics》2002,17(4):427-440

We present a new method of image cleaning for imaging atmospheric Cherenkov telescopes. The method is based on the utilization of wavelets to identify noise pixels in images of gamma-ray and hadronic induced air showers. This method selects more signal pixels with Cherenkov photons than traditional image processing techniques. In addition, the method is equally efficient at rejecting pixels with noise alone. The inclusion of more signal pixels in an image of an air shower allows for a more accurate reconstruction, especially at lower gamma-ray energies that produce low levels of light. We present the results of Monte Carlo simulations of gamma-ray and hadronic air showers which show improved angular resolution using this cleaning procedure. Data from the Whipple Observatory's 10-m telescope are utilized to show the efficacy of the method for extracting a gamma-ray signal from the background of hadronic generated images.  相似文献   

Cosmic Ray Acceleration Inside Molecular Clouds     

V. A. Dogiel  A. V. Gurevich  Ya. N. Istomin  K. P. Zybin 《Astrophysics and Space Science》2005,297(1-4):201-211

Acceleration of charged particles by neutral gas turbulence in giant molecular clouds is considered. The gamma-ray emission from these clouds is estimated. It is shown that molecular clouds can be the counterparts of some of unidentified sources.  相似文献   

Analysis of the spatial distribution of gamma-ray bursts in their host galaxies     

S. I. Blinnikov  K. A. Postnov  D. I. Kosenko  O. S. Bartunov 《Astronomy Letters》2005,31(6):365-374

We compare the radial distributions of known localized gamma-ray bursts (GRBs) relative to the centers of their host galaxies with the distributions of known objects in nearby galaxies (supernovae of various types, X-ray binaries), the hypothetical dark-matter profiles, and the distribution of luminous matter in galaxies in the model of an exponential disk. By comparing the moments of empirical distributions, we show that the radial distribution of GRBs in galaxies differs significantly from that of other sources. We suggest a new statistical method for comparing empirical samples that is based on estimating the number of objects within a given radius. The exponential disk profile was found to be in best agreement with the radial distribution of GRBs. The distribution of GRBs relative to the centers of their host galaxies also agrees with the dark matter profile at certain model parameters.  相似文献