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1.
V. L. Afanasiev S. N. Dodonov A. V. Moiseev V. Chavushyan R. Mujica Y. Juarez A. G. Gorshkov V. K. Konnikova M. G. Mingaliev 《Astronomy Letters》2003,29(9):579-586
We present the classification of optical identifications and radio spectra of six radio sources from a complete (in flux density) sample in the declination range 10° to 12°30′ (J2000.0). The observations were carried out with the 6-m Special Astrophysical Observatory telescope (Russia) in the wavelength range 3600–10000 Å, the 2.1-m GHAO telescope (Mexico) in the range 4200–9000 Å, and the RATAN-600 radio telescope in the frequency range 0.97–21.7 GHz. Three of the six objects under study are classified as quasars, one is a BL Lac object, one is an absorption-line radio galaxy, and one is an emission-line radio galaxy. Five objects have flat radio spectra, and one object has a power-law radio spectrum. All of the radio sources identified as quasars or BL Lac objects show variable radio flux densities. The spectra of three objects were separated into extended and compact components. 相似文献
2.
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
3.
G. P. Apushkinskij N. A. Topchilo A. N. Tsyganov N. S. Nesterov 《Astronomische Nachrichten》1996,317(6):417-421
The first successful radio astronomical results of measurements of the magnetic field of solar prominences are presented. The accuracy of polarization and magnetic field observations is 3 · · 10−4 and 2 G, respectively. The observations were made by the 22-meter radio telescope of the Crimean Astrophysical Observatory at wavelengths of 8 and 13.5 mm. It has been found that the value of the magnetic fields coincides with the optical one (from 7 to 30 G), but the image of radio polarization differs from the intensity. 相似文献
4.
A. Baudry J. Brillet J. M. Desbats J. Lacroix G. Montignac P. Encrenaz R. Lucas G. Beaudin P. Dierich A. Germont P. Landry G. Rerat 《Journal of Astrophysics and Astronomy》1980,1(2):193-196
A new millimeter-wave facility is in operation at the Bordeaux Observatory for spectroscopic observations of interstellar
and stratospheric molecules. A cooled receiver has been installed on a 2·5m radio telescope. The overall system temperature
is in the range 400 to 600 K (single side band) in the operating frequency range 75 to 115 GHz. The relatively broad beam
of the telescope (∼ 5 arcmin) combined with a sensitive receiver will permit studies of extended molecular cloud complexes. 相似文献
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描述了采用光学望远镜辅助天马13m射电望远镜进行指向测量以及建立指向误差修正模型的方法. 对于小口径望远镜, 指向校准目标源比较少, 用射电法建立指向模型难以覆盖全天区. 利用上海天文台天马13m射 电望远镜进行光学望远镜辅助射电望远镜指向测量研究, 在13m天线背架上安装一套光学指向系统, 获得了优 于3''的重复测量误差. 此外, 通过对影响天线指向因素的分析, 建立了包含8个误差项的指向误差修正模型以及 光轴和电轴偏差模型. 将指向模型代入天线伺服控制系统, 对校准目标射电源进行十字扫描, 得到指向样本残差约 为5''. 该研究可以为实现高精度指向建模提供一种参考方法. 相似文献
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QUaD is a 31 pixel array of polarization sensitive bolometer pairs coupled to a 2.6 m Cassegrain radio telescope. The telescope is attached to the mount originally built for the DASI experiment and located at the South Pole. The telescope system is described along with details of instrumental characterization studies which we have performed. A first season of CMB observations is complete and the second season underway. Details of the current status of these observations and their analysis are presented. 相似文献
8.
Shu-Mo Gong 《Astrophysics and Space Science》1986,118(1-2):15-20
This paper covers the main aspects of three new optical telescopes: a 1.26 m aperture one for use in the infrared, a 1.56 m aperture one for astrometry, and a 2.16 m reflector for general astrophysical work. It also briefly mentions the 13.7 m telescope designed for the mm wavelength band, the first VLBI in China and the meter wavelength aperture synthesis telescope. All these telescopes, optical and radio, are now being built in China.Paper presented at the IAU Third Asian-Pacific Regional Meeting, held in Kyoto, Japan, between 30 September–6 October, 1984. 相似文献
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制冷接收机是射电望远镜的核心设备,它是否正常工作直接决定望远镜观测的效果。制冷接收机的制冷温度和杜瓦真空度是反映接收机是否正常工作的最重要、最直接的指标之一。因此实现制冷接收机制冷温度和杜瓦真空度的远程实时监控,及时了解接收机是否正常工作对保证射电望远镜正常运行、提高观测效率有重要意义。为乌鲁木齐天文站25m射电望远镜1.3cm制冷接收机研制的一套基于单片机和以太网的数据采集和数据传输的远程监视系统,实现了制冷接收机制冷温度和杜瓦真空度的远程实时监控。该系统采用了美国ATMEL公司生产的8位单片机AVR ATmega16、Microchip Technology公司生产的ENC28J60以及MAXIM公司生产的MAX7219,实现对射电天文制冷接收机制冷温度和杜瓦真空度的数据采集,并利用以太网传输数据实现了远程实时监控接收机的制冷状态。阐述了以太网数据采集及远程监控电路的设计原理及其实现方法。该系统首次在国内大型射电望远镜上实现了对制冷接收机工作状态的远程实时监控,对于保证乌鲁木齐天文站25m射电望远镜1.3cm波段的观测效果有重要作用。 相似文献
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电磁兼容性是设备或系统的重要性能指标, 也是保障系统的工作效能和提高系统可靠性的重要因素. 大口径射电望远镜运行阶段, 台址周围无线电业务及内部潜在的电磁干扰会降低观测系统灵敏度、影响天文观测的质量. 本论文针对拟建的新疆110 m全向可动射电望远镜(Qi Tai raido Telescope, QTT)开展了系统电磁兼容评估技术及控制方法研究, 具有重要的工程应用价值. 首先, 依据现有电波环境测量方法的不足, 深入分析了仪器设备的关键参数配置方法及测量时间计算方法, 采用Y因子法校准测量数据, 提出一种准实时电波环境测量方法. 面向高重复性宽带频谱, 分析了宽带频谱信号和噪声特征, 结合标准差理论, 提出一种基于邻值比较的信噪分离方法, 并采用邻值统计方法优化关键参数, 提高信噪分离精度. 针对QTT台址, 开发了自动化电波环境监测系统, 该系统6 GHz以下频段系统增益大于40 dB, 系统噪声系数小于2 dB, 测量不确定度小于1.49 dB, 具有极高的系统灵敏度和测量精度; 分析了频谱监测数据流, 设计了基于HDF5 (Hierarchical Data Format version 5)的数据存储格式, 开发了自动化电波环境测量和监控软件及数据处理软件. 依据QTT台址长期监测数据, 评估分析了台址电磁环境、主要干扰源特征及其影响. 其次, 提出大口径射电望远镜馈源口面干扰电平限值量化方法, 建立了基于台址地形的电波传播模型, 分析了现有电波传播模型的优缺点及适应性, 结合QTT台址实际地形及地质特征, 采用Longley-Rice和Two-Ray电波传播模型, 预测分析了QTT台址潜在干扰区域电磁干扰达到射电望远镜的电波路径衰减, 结合大口径射电望远镜天线增益量化方法, 提出设备所在位置干扰电平限值量化方法, 运用该方法对QTT台址潜在干扰区域的干扰电平限值进行量化. 依据设备所在位置干扰电平限值, 调研分析了国内外军用、民用电磁兼容测量标准, 结合电磁干扰对射电天文观测的影响, 提出一种大口径射电望远镜电磁兼容控制方法, 解决了现有电波暗室测量系统无法直接测量评估电子设备电磁兼容的问题, 该电磁兼容控制方法计划应用于QTT建设及运行阶段, 确保系统拥有良好的电磁兼容性. 最后, 依据QTT台址潜在干扰区域干扰电平限值, 结合典型电子设备电磁辐射频谱, 分析了QTT电磁兼容设计需求, 提出电磁兼容设计初步方案. 另外, 针对台址建筑设施内的中低电磁辐射干扰源, 提出一种低成本建筑屏蔽方法, 应用于QTT台址现有建筑. 相似文献
12.
Norio Kaifu 《Astrophysics and Space Science》1989,160(1-2):27-29
The current achievements of the observational abilities of radio astronomy is briefly reviewed putting emphasis on the imaging capability. The new projects in radio astronomy are discussed in connection with the new generation of optical/IR telescope projects.Paper presented at the Symposium on the JNLT and Related Engineering Developments, Tokyo, November 29–December 1988. 相似文献
13.
Li Zhen-qiang Li Ji-bin Zhang Xu-guo Shan Wen-lei Xu Ye Zuo Ying-xi Zhang Hai-long Jin Feng-juan Sun Ji-xian Lu Deng-rong Ju Bing-gang 《Chinese Astronomy and Astrophysics》2019,43(4):590-608
In astronomical observations, the radio frequency interference (RFI) will cause pseudo spectra and reduce the reliability and validity of observational data. The RFI mitigation, which includes many technical innovations of devices and the method studies of data processing, aims at reducing the influence of RFI on the radio astronomical observation. Various efforts were made to improve the anti-RFI capability of the multi-beam receiver (Superconducting Spectroscopic Array Receiver, SSAR) of the Delingha 13.7 m telescope. The interference transmission path was analyzed. The concepts of the device RFI direct coupling coefficient and the device RFI system coupling coefficient were proposed. The proportions of interference introduced in the receiver system by the different devices were quantified, and the interference-susceptible devices in the system were located. After the anti-RFI treatment of the interference-susceptible devices, the anti-RFI capability of the receiver system is improved by 30 dB in average, and the astronomical observation efficiency of the telescope is increased by more than 10%. 相似文献
14.
C. H. Ishwara-Chandra D. J. Saikia P. J. McCarthy W. J. M. van Breugel 《Monthly notices of the Royal Astronomical Society》2001,323(2):460-470
We present multi-wavelength radio observations with the Very Large Array, and narrow- and broad-band optical observations with the 2.5-m telescope at the Las Campanas Observatory, of a well-defined sample of high-luminosity Fanaroff–Riley class II radio galaxies and quasars, selected from the Molonglo Reference Catalogue 1-Jy sample. These observations were carried out as part of a programme to investigate the effects of orientation and environment on some of the observed properties of these sources. We examine the dependence of the Liu–Pooley relationship, which shows that radio lobes with flatter radio spectra are less depolarized, on size, identification and redshift, and show that it is significantly stronger for smaller sources, with the strength of the relationship being similar for both radio galaxies and quasars. In addition to Doppler effects, there appear to be intrinsic differences between the lobes on opposite sides. We discuss the asymmetry in brightness and location of the hotspots, and present estimates of the ages and velocities from matched-resolution observations in the L and C bands. Narrow- and broad-band optical images of some of these sources were made to study their environments and correlate with the symmetry parameters. An extended emission-line region is seen in a quasar, and in four of the objects possible companion galaxies are seen close to the radio axis. 相似文献
15.
Nine of the cataloguedHii regions in the southern hemisphere have been selected for correlation with neutral hydrogen observed at the 21 cm line.The radiotelescope used for theHi line observations was the 30 m Carnegie telescope of the Instituto Argentino de Radioastronomía and the 56 channel, 10 KHz bandwidth receiver.The observational results are analyzed for eachHii region. They are compared with previous optical and radio results.For three of the nine observed regions it has been possible to find neutral hydrogen in absorption with similar velocities. In three cases absorption has been found but no component at theHii region velocity is seen. Finally in three cases, it has not been possible to find any absorption at all.Member of the Carrera del Investigador Científico del Cosejo Nacional de Investigaciones Científicas y Técnicas. 相似文献
16.
This article introduces the new Indian 2 m telescope which has been designed by MT Mechatronics in a detailed conceptual design study for the Indian Institute of Astrophysics, Bangalore. We describe the background of the project and the science goals which shall be addressed with this telescope. NLST is a solar telescope with high optical throughput and will be equipped with an integrated Adaptive Optics system. It is optimized for a site with the kind of seeing and wind conditions as they are expected at a lake site in the Himalayan mountains. The telescope can also be used for certain night time applications. We also give the scientific rationale for this class of telescope (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim) 相似文献
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K.. Gabnyi N. Marchili T.P. Krichbaum S. Britzen L. Fuhrmann A. Witzel J.A. Zensus P. Müller X. Liu H.G. Song J.L. Han X.H. Sun 《Astronomische Nachrichten》2007,328(8):863-866
Short time‐scale radio variations of compact extragalactic radio quasars and blazars known as IntraDay Variability (IDV) can be explained in at least some sources as a propagation effect; the variations are interpreted as scintillation of radio waves in the turbulent interstellar medium of the Milky Way. One of the most convincing observational arguments in favor of a propagation‐induced variability scenario is the observed annual modulation in the characteristic time scale of the variation due to the Earth's orbital motion. So far there are only two sources known with a well‐constrained seasonal cycle. Annual modulation has been proposed for a few other less well‐documented objects. However, for some other IDV sources source‐intrinsic structural variations which cause drastic changes in the variability time scale were also suggested. J1128+592 is a recently discovered, highly variable IDV source. Previous, densely time‐sampled flux‐density measurements with the Effelsberg 100‐m radio telescope (Germany) and the Urumqi 25‐m radio telescope (China), strongly indicate an annual modulation of the time scale. The most recent 4 observations in 2006/7, however, do not fit well to the annual modulation model proposed before. In this paper, we investigate a possible explanation of this discrepancy. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim) 相似文献
19.
G. Swarup 《Journal of Astrophysics and Astronomy》1984,5(2):139-148
A 4-km synthesis radio telescope has recently been commissioned at Ootacamund, India for operation at 327 MHz. It consists
of the Ooty Radio Telescope (530 m × 30 m) and 7 small antennas which are distributed over an area of about 4 km × 2 km. It
has a coverage of about ± 40‡ in declination δ. The beam-width is about 40 arcsec × 90 arcsec at δ = 0‡ and about 40 arcsec
× 50 arcsec at δ = 40‡. The sensitivity attained for a 5:1 signal-to-noise ratio is about 15 m Jy after a 10-hour integration.
The observational programmes undertaken and some of the results obtained recently are summarized. The radio halo around the
edge-on spiral NGC 4631 is found to have a larger scale-height at 327 MHz than is known at higher frequencies. Mapping of
interesting radio galaxies at 327 MHz is being carried out; preliminary results for 0511-305 (∼2 Mpc) and 1333-337 (∼750 kpc)
are summarized. The very-steep-spectrum radio source in the Abell cluster A85 is found to be resolved; since it has no obvious
optical counterpart, it is conceivable that it is a remnant of past activity of a galaxy that has drifted away in about 109 years. 相似文献
20.
射电望远镜的发展和前景 总被引：1，自引：0，他引：1
在近代科学技术发展的基础上诞生和成长起来的射电天文学已经走过了66年的历程,作为射电天文学主要探测工具的射电望远镜有了长足的进步,面临21世纪人类社会和自然科学技术包括天文学发展的挑战,射电望远镜及射电天文学将迈出新的步伐．从射电天文学和射电望远镜发展的关系、射电望远镜几个主要发展方向和目前水平、自90年代以来逐步勾画而明确起来的未来发展方向等方面阐明了射电望远镜的发展和前景,以作为我国发展新一代射电望远镜的参考． 相似文献