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鉴于ＩＥＲＳ综合河外射电源表在建立ＩＡＵ协议天球参考架方面的重要意义和它们的不足之处，本文重新组建了１９８８至１９９２各年度的综合河外射电源表，称之为Ｃａｔ系列表。并依据综合表的组建原理，对重新计算得到的Ｃａｔ系列表进行了检验，结果表明Ｃａｔ系列表克服了ＩＥＲＳ系列表中坐标系不统一的缺点，指向的定义及维持亦较之ＩＥＲＳ系列表有较大程度地改观。比较结果显示，ＩＥＲＳ系列表中部分源的坐标存在毫角秒量级的偏差，各年度综合表的指向与ＩＥＲＳ预期指向亦有不同程度的偏离，个别轴的最大指向偏差至０．６ｍａｓ。同时指出，１９９３年ＩＥＲＳ综合表的指向亦有待讨论。 相似文献
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本文对ＩＥＲＳ综合河外射电源表进行了检验，指出１９８８至１９９１各年度的ＩＥＲＳ综合河外射电源表中均存在坐标系统不一致问题，部分射电源的位置坐标中带有几个毫角秒的偏差，与公认精度不符，坐标系统不一致问题影响了ＩＥＲＳ综合表的指向维持，使此维持仅限于数学意义上的平均水平，失去了明确的物理意义。 相似文献
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河外射电源在IERS综合表与观测表中坐标差的特性分析 总被引：1，自引：0，他引：1
本文简要介绍了ＩＥＲＳ综合河外射电源表在所用资料、建立方法等方面的一般情况，进而分析了河外射电源在ＩＥＲＳ综合表与观测表中的坐标表的一般特性，为检验综合表提供了分析基础。 相似文献
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鉴于ＩＥＲＳ综合河外射电源表在建立ＩＡＵ协议天球参考架方面的重要意义和它们的不足之处，本文重新组建了１９８８至１９９２各年度的综合河外射电源表，称之为Ｃａｔ称列表，并依据综合表的组建原理，对重新计算得到的Ｃａｔ系列表进行了检验，结果表明Ｃａｔ系列表克服了ＩＥＲＳ系列表中坐标系不统一的缺点，指向的定义及维持亦较之ＩＥＲＳ系列表有较大程度地改观。比较结果显示，ＩＥＲＳ系列表中部分源的坐标存在毫角秒量级 相似文献
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光学选射电噪类星体的射电性质 总被引：1，自引：0，他引：1
对类星体进行多波段的观测和研究,是了解类星体本质的一个重要途径．LBQS类星体是目前公认较为完备的一个光学选类星体样本,利用此样本与最新的485GHz全天射电源表进行了交叉证认,共找到了34个类星体的对应射电源．计算证明,这34个类星体都是射电噪的类星体．所得研究结果表明,射电噪类星体的射电光度与光学光度之间存在线性相关性． 相似文献
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综合河外射电源表的编制方法评述 总被引：1，自引：0，他引：1
简要介绍了编制综合外射电源表的几处方法，分析了它们各自的特点。详细讨论了ＩＥＲＳ编制方法及其系列综合表中存在的一些问题，并这些问题提出了一些改进意见。 相似文献
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H. G. Walter 《Celestial Mechanics and Dynamical Astronomy》1992,53(1):71-80
Observation catalogues of extragalactic radio sources obtained by Very long Baseline Interferometry during the last decade agree in the mean to a few milliarcseconds (mas). Within this range the position differences show constant, linear and periodic offsets. To reduce the influence of individual catalogue properties the construction of a compilation catalogue seems to be the appropriate procedure. In some detail the compilation method is described providing simultaneous adjustment of source positions and catalogue corrections. The compilation catalogue consists of 40 objects having positional errors of 0.2 mas in right ascension (RA) and 0.3 mas in declination (Dec). Comparing this catalogue with the IERS Celestial Reference Frame compiled by means of other precepts yields weighted root-mean-square differences of 0.7 mas in RA and 1.3 mas in Dec. Finally, the terms of general precession in RA and Dec are included in the adjustment process giving estimates of the correction to the luni-solar precession between –1 and –3 mas/yr, the latter figure applying when some early data are added. 相似文献
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C. R. Kerton J. Murphy J. Patterson 《Monthly notices of the Royal Astronomical Society》2007,379(1):289-296
A new catalogue of extended radio sources has been prepared based on arcminute-resolution 1420-MHz images from the Canadian Galactic Plane Survey (CGPS). The new catalogue provides both 1420- and 408-MHz flux density measurements on sources found near the Galactic plane in the second quadrant of our Galaxy. In addition cross-identifications are made with other major radio catalogues and information is provided to facilitate the recovery of CGPS image data associated with each catalogued source. Numerous new radio sources are identified and the catalogue provides a comprehensive summary of both newly discovered and previously known H ii regions and supernova remnants in the outer Galaxy. The catalogue should be of use both for synoptic studies of Galactic structure and for placing higher resolution observations, at radio and other wavelengths, in context. 相似文献
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H. G. Walter 《Astrophysics and Space Science》1991,177(1-2):97-103
A combined catalogue is constructed from the observations of extragalactic radio sources compiled in independent catalogues providing precise positions determined by radio interferometric techniques. Positions and catalogue differences are derived and discussed. The average precision of the combined catalogue is at the level of 0.7 mas in right ascension and 1.3 mas in declination. For the more recent catalogues the systematic differences amount to a fraction of a millisecond of arc. 相似文献
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According to the decision of the International Astronomical Union (IAU), since 1998 the International Celestial Reference System has been realized by the ICRF catalogue of extragalactic radio source positions obtained from VLBI observations. Over the past years, the accuracy of the ICRF catalogue data has been increased only through an increase in the number and quality of observations and an improvement in the methods of their processing. Both the first ICRF version and the new ICRF2 version adopted by the IAU in 2009 are based on the catalogues obtained at the same VLBI data processing center. However, the experience of classical astrometry shows that a significant increase in the accuracy of the International Celestial Reference Frame can be achieved by creating combined catalogues, such as the fundamental catalogues of star positions. The same approach was applied to improve the ICRF catalogue. Even the first experience of such a combined solution has shown its high efficiency. Here, a new combined catalogue of radio source positions PUL(2013)C02 is presented. Mainly classical methods based on the expansion of the systematic differences between the input catalogues into series of orthogonal functions with additional improvements have been applied for its creation. Comparison of the combined catalogue obtained with the ICRF2 catalogue has shown that the latter is most likely not devoid of systematic errors at a level of 15–20 μas. 相似文献
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Audra Baleisis Ofer Lahav rew J. Loan & Jasper V. Wall 《Monthly notices of the Royal Astronomical Society》1998,297(2):545-558
We calculate the expected amplitude of the dipole and higher spherical harmonics in the angular distribution of radio galaxies. The median redshift of radio sources in existing catalogues is z ∼ 1, which allows us to study large-scale structure on scales between those accessible to present optical and infrared surveys, and that of the cosmic microwave background (CMB). The dipole is a result of two effects which turn out to be of comparable magnitude: (i) our motion with respect to the CMB, and (ii) large-scale structure, parametrized here by a family of cold dark matter power-spectra. We make specific predictions for the Green Bank 1987 (87GB) and Parkes–MIT–NRAO (PMN) catalogues, which in our combined catalogue include ∼ 40 000 sources brighter than 50 mJy at 4.85 GHz, over about 70 per cent of the sky. For these relatively sparse catalogues both the motion and large-scale structure dipole effects are expected to be smaller than the Poisson shot noise. However, we detect dipole and higher harmonics in the combined 87GB–PMNraw catalogue which are far larger than expected. We attribute this to a 2 per cent flux mismatch between the two catalogues. Ad hoc corrections made in an effort to match the catalogues may suggest a marginal detection of a dipole. To detect a dipole and higher harmonics unambiguously, a catalogue with full sky coverage and ∼ 106 sources is required. We also investigate the existence and extent of the supergalactic plane in the above catalogues. In a strip of ± 10° of the standard supergalactic equator, we find a 3 σ detection in PMNraw , but only 1 σ in 87 GBraw . We briefly discuss the implications of ongoing surveys such as FIRST and NVSS and follow-up redshift surveys. 相似文献
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N. V. Kharchenko V. S. Kislyuk S. F. Rybka A. I. Yatsenko 《Astrophysics and Space Science》1991,177(1-2):65-71
The works of the Goloseevo Observatory (Kiev, U.S.S.R.) on the compilation of catalogues of absolute proper motions measured with respect to faint galaxies are discussed. Using these catalogues, some astrometric and stellar characteristics have been obtained. Particular attention is paid to the problem of improving the accuracy of stellar position and proper motion determinations. The optimum procedure for compiling the consolidated catalogue intended for the improvement of fundamental reference frame, kinematic characteristics of stars as well as for the solution of applied problems is developed. 相似文献
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S. E. G. Hales J. M. Riley E. M. Waldram P. J. Warner J. E. Baldwin 《Monthly notices of the Royal Astronomical Society》2007,382(4):1639-1642
We present a final unified catalogue for the 7C survey at 151 MHz with resolution 70 × 70 cosec(δ) arcsec2 . This has been constructed by amalgamating the existing catalogues derived from individual fields imaged at this resolution and eliminating redundancy in regions of mutual overlap. This is a non-trivial procedure because the flux in multiple-component sources may be fitted differently on alternative images, owing, for example, to differences in local noise and beam distortion. The final catalogue lists 43683 sources over an area of about 1.7 sr. Separate final catalogues have been published for the 7C Galactic Plane survey (7CG) and the lower-resolution survey of the low-declination strip 9h < RA < 16h , 20° < Dec < 35° . 相似文献