为什么天文不受重视

有一位署名“lazy1004”的天文爱好者给我写信,表达了一个很具有代表性的疑问：天文学在学校中为何不受重视？他（或她）写道：“同为六大自然学科,偏偏没有开设天文课,即使有。也只是一个星期才一节的选修课。给我们上课的是一位地理老师．他是一位狂热的天文爱好者,但似乎比校长还忙。学校的望远镜坏了,校方也一拖再拖,迟迟没有联系人来修。这样的选修课在他们眼中是那么的不重要。所有的人都在为考试而忙碌。这让我感到孤独。为什么？!”     

彗星动态榜

最新发现： 2008年8月发现并命名了5颗彗星,其中包括一颗重新发现的周期彗星。     

2008年12月重要天象预告

不知不觉,我们已经迎来了今年的最后一月。而璀璨的冬夜星空,以及本月几个值得期待的重要天象,也将为2008年画上圆满的句号。     

四百年的大课

10月12日,一场科学大师演讲会在人民大会堂举行。这是为了纪念望远镜发明400周年。发表演讲的科学大师共有三位,分别是诺贝尔奖得主美籍华裔科学家李政道、美籍意大利裔科学家里卡尔多·贾科尼和邵逸夫天文学奖得主美国科学家杰弗里·马西。     

第十五批天文学名词的推荐译名

中国天文学会名词审定委员会从1985年开始在<天文学进展>发表天文学名词的推荐译名,到2007年已公布了14批2280个名词.现再推荐第十五批151个名词,其中大多数是近年来出现的天文学新词.希望读者在试用过程中对译名提出改进意见.     

岁差模型研究的新进展——P03模型

简述了岁差P03模型提出的背景情况;指出IAU1976岁差模型的缺陷, IAU 2000A岁差和章动模型中虽有改进但仍不完善;对IAU2006岁差模型(即Capitaine提出的P03模型)作了介绍,并将其与其他岁差模型L77、B03和F03进行了比较;述及GCRS至ITRS的2种表达方法,基于春分点的岁差和章动旋转角方法和运动参考架CIO的X、Y、s的方法;给出了CIP和CIO位置确定的各种方法以及其精度;最后叙述了20世纪IAU采用的岁差一章动模型和IAU天文常数工作组的有关情况,给出了在惯性参考架中"非旋转原点"的运动.     

Observations of Giant Pulses of the Crab Pulsar

The Crab Pulsar was observed at 1540 MHz with the 25m radio telescope at Urumqi with a filterbank de-dispersion backend. A total of 2436 giant pulses with pulse energies larger than 4300 Jy μs were detected in two observing sets. All of these giant pulses are located in the main pulse (MP) and inter pulse (IP) windows of the average profile of the Crab Pulsar. The ratio of the numbers of giant pulses detected in the IP and MP windows is about 0.05. Our results show that, at 1540 MHz, the emission in the IP is contributed by giant and normal pulses, while that in the MP is almost dominated by giant pulses. The distribution of energy of the 2436 giant pulses at 1540 MHz can be described by a power-law with index α=3.13±0.09. The intrinsic threshold of giant pulse energy in the MP window is about 1400 Jy μs at 1540 MHz.     

Feedback of Active Galactic Nuclei in Seyfert 2 Galaxies

It is well accepted that feedback from active galactic nuclei (AGNs) plays an important role in the coevolution of the supermassive black hole (SMBH) and its host galaxy,but the concrete mechanism of feedback remains unclear.A considerable body of evidence suggests that AGN feedback suppresses star formation in the host galaxy.We assemble a sample of Seyfert 2 galaxies with recent observational data of compact nuclear starbursts and estimate the gas surface density as a function of column density to illuminate the relation between feedback and AGN properties.Although there are some uncertainties,our data still imply the deviation from the star formation law (Kennicutt-Schmidt law).Further,they indicate that:(1) Feedback correlates with the Eddington ratio,rather than with the mass of SMBH,as a result of decreasing star formation efficiency.(2) The SMBH and the torus are probably undergoing coevolution.Conclusions presented here can be refined through future high resolution CO or HCN observations.