Spatial and velocity coincidence of 4765- and 1720-MHz OH masers in two star-forming regions Cep A and W75N     

A. Niezurawska  M. Szymczak  R. J. Cohen  A. M. S. Richards 《Monthly notices of the Royal Astronomical Society》2004,350(4):1409-1415

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Clues to starburst evolution: The tale of dense gas     

Susanne Hüttemeister  Susanne Aalto 《Astrophysics and Space Science》2003,284(2):877-880

The dense gas tracers HNC and CN prove to be detectable in sensitive single dish studies of infrared luminous starburst galaxies. Their line intensity with respect to both the standard tracer of molecular gas, CO, and the dense, starforming component, HCN, varies significantly. This opens a new, extinction-free window into the investigation of the properties and the evolutionary stage of starbursts. This revised version was published online in August 2006 with corrections to the Cover Date.  相似文献   

Experimental Research of First Feed-Support System of FAST     

Liming Yu  Francis Tay Eng Hock  Shuangfu Suo  Gexue Ren 《Experimental Astronomy》2003,15(2):113-122

First feed support system, which is one of the key technologies of Five hundred meter Aperture Spherical Telescope (FAST) was discussed in this paper. A 1:30 scaled model (20 m × 20 m × 6 m) has been built to make systemic research on the feasibility of the system. The root mean square of pointing error of moving cable car was measured and the displacements of cable car within the wind speed of 8 m/s, which is the maximal wind speed of the place where the FAST will be located, were evaluated. Then the total maximal pointing error of cable car was computed. Experimental results demonstrate that the total pointing error of the cable car is less than 50 cm, the required pointing accuracy error of the system. This revised version was published online in July 2006 with corrections to the Cover Date.  相似文献   

No evidence for coherent diffractive radiation patterns in the millisecond pulsar PSR J0437–4715     

M. Vivekanand 《Monthly notices of the Royal Astronomical Society》2001,324(4):L29-L32

An independent analysis of the 326.5-MHz data obtained by the Ooty Radio Telescope reveals no evidence for coherent diffractive radiation patterns in the millisecond pulsar PSR J0437–4715 .  相似文献   

Radio emission from AXP and XDINS     

V. M. Malofeev  O. I. Malov  D. A. Teplykh 《Astrophysics and Space Science》2007,308(1-4):211-216

The result of the search for, and the observations of radio emission from two groups of isolated neutron stars: AXP 1E 2259+586 and XDINS 1RXS J1308.6+212708 and 1RXS J214303.7+065419 are reported. The observations were carried out on two sensitive transit radio telescopes at a few frequencies in the range 42–112 MHz. The flux densities, mean pulse profiles, as well as, the estimation of the dispersion measures, distances and integrated radio luminosities of all objects are presented. Comparison with X-ray data shows large differences in the mean pulse widths and luminosities.   相似文献   

Sub-arcsecond atomic hydrogen absorption in the Seyfert galaxies NGC 7674 and NGC 7469     

R. J. Beswick  A. Pedlar  A. R. McDonald 《Monthly notices of the Royal Astronomical Society》2002,335(4):1091-1099

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CRITICAL HYDROLOGIC CONDITIONS FOR OVERFLOW BURST OF MORAINE LAKE     

JIANG Zhong-xin  CUI Peng  JIANG Liang-wei 《中国地理科学(英文版)》2004,14(1):39-47

1OVERFLOWBURSTOFMORAINELAKEFloodwater and debris flow caused by glacial lake burst is an important land process and a serious moun-tain disaster in glacial area. Glacial lakes with burst can divided into the glacier-obstructed lake (ice dam lake) and the terminal moraine lake (XU and FENG, 1988). Typical burst of ice dam lake happens in the modern glacier area of the upper reaches of the Kele-qing River in Uygur Autonomous Region of Xinjiang (WANG, 1990). But most of burst gla…  相似文献   

高频VLBI观测射电源的结构     

田文武吴盛殷  张海燕 《天文研究与技术》2001,(2):1-9

高频VLBI观测揭示出河外射电源在pc或者亚pc尺度上大都有核-喷流的内部结构。尤其是对平谱致密射电源中毫角秒尺度的子源，能以相当高的概率观测到它的视超光速现象。多频观测可监测到一些新喷流子源的出现，特别在射电激变源中这些新喷流子源的出现与宽带内(从光学到γ射线)的爆发相关。且得到的一些源的核区谱指数分布，为确认源的VLBI核提供了支持。  相似文献   

几个极高光度IRAS星系的射电频谱     

苏步美  李永生  高亦菲  符好文 《天文学报》2001,42(4):408-413

使用澳大利亚致密阵（ATCA）对一个红外光度高达10^11.8-10^12.8L⊙的IRAS星系样本进行了8.6,4.8,2.4和1.4GHz的射电观测，发现其中有4个源在高频为陡谱，在较低频率上流星降低，呈峰状，峰值在几GHz。讨论了造成频谱倒转的两种可能机制：同步自吸收和free-free吸收。通过对00199－7426，02587－6336，07020－5423和21547－5823的频谱分析，我们认为free-free吸收可能导致了低频倒转谱的形成。通过对观测数据的模拟，获得了这几个源的有关物理参量。  相似文献   

来自6538活动区的太阳射电米波事件     

马媛  郑向明 《天文研究与技术》2001,(1):19-25

利用云南天文台声光频谱仪在1991年3月记录到的太阳射电米波辐射事件、光学活动及相关事件作了分析，得到来自6538活动区太阳射电米波事件的一些基本特性。  相似文献