共查询到20条相似文献，搜索用时 388 毫秒
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用M15进行CCD视场的校准 总被引：3，自引：2，他引：1
用1996年10月所获得的球状星团M15和大距离双星61Cygni的CCD观测资料,分别求解了上海天文台1.56m天体测量望远镜上安装的CCD探测器视场的位置角改正δp和尺度因子ρ。通过对土星主要卫星观测资料0－C的计算分析表明,经球状星团校准视场后所得结果较双星校准后结果的精度要高。该结论为进一步提高计算大行星卫星的位置测量精度打下良好的基础。 相似文献
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空间载钟的天体物理学实验 总被引：3，自引：0，他引：3
原子钟在空间天体物理测量中起着重要作用。最近研制的氢原子钟,对于超过1,000秒的平均时间间隔,其稳定度好到10~(-16)。这些装置对空间VLBI高精度的角度测量以及多普勒技术高精度测距和测速是非常适用的。本文主要概述几个通常感兴趣的空间载钟的天体物理实验.为了作这些测量,实验必须扩展到太阳系内进行。 相似文献
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一、引言法国P.Lacroute教授首次提出在空间人造卫星上进行基本天体测量观测的建议,最近已由ESA(欧洲空间局)专家小组做了全面的分析和研究,其结果构成A阶段的研究报告,即《空间天体测量》一文。在空间进行观测具有深远的意义,预期其所得结果不但会影响基本天体测量将来的发展方向,也将大大推动整个天文学的进程。然而,在天体测量学这种革命性变革的前夜,地面基本天体测量是否还应该继续发展、前进?本文最后三节将试图讨论这个问题。二、空间天体测量的前景和意义 相似文献
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天体测量学是天文学的一个分枝.天体测量学是研究测量天体在天空的方向的方法,是研究测定天体的位置和运动的方法.目视天体测量的主要困难是如何将所有的量度测定到尽可能的精确,这些量度都是对起始方向和起始平面而言的.起始方向和起始平面就是地轴和二分点平面,因此,我们所采用的方向和平面就得彼此完全平行.这样我们才能进行绝对坐标和恒星自行的测量. 相似文献
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CCD图像数字定心算法的比较 总被引：13，自引：0，他引：13
从CCD采集的数字图像中提取天体的位置和光度信息对于天文研究具有基础意义.其中,恒星星像中心像素位置的精确测量对于天体测量至关重要.针对国际上常用的三种位置测量算法:修正矩方法、Gauss拟合法和中值法,利用实测的CCD图像进行了试验研究.具体地,采用云南天文台1m望远镜观测的CCD图像同时使用这些算法进行了实际测量,根据每幅图像中测得的像素位置,对这三类定心算法进行了比较和精度分析.可视化方法被用于不同阈值的选取和设定比较.实验数据表明,无阈值的二维Gauss拟合方法是一种精度相对较高的定心算法. 相似文献
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天文发现十八法（下）北京天文台台长李启斌本文的上半部分，介绍了发现天体的方法和测量天体特性的方法。这一部分着重讲述推理的方法以及创新乃至突破的方法。由于天文学的对象的不可接触性，不能把天体拿来做实验，按照我们的意志，按照认识的需要去测量它们的特性。可... 相似文献
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Jason C.W. Corbett Tim J. Morris Jeremy R. Allington-Smith 《New Astronomy Reviews》2006,49(10-12):675
Single-mode fibres do not suffer from modal noise and are available in polarisation maintaining form. Single-mode photonic crystal fibres (smPCF) have a wavelength insensitive mode field allowing coupling of the telescope exit pupil into the fibre using a lenslet with a flat spectral response. This may allow single-mode Integral Field Spectroscopy (IFS) and fibre fed integral field spectro-polarimetry. Initial results from a theoretical analysis of telescope/smPCF coupling using a lenslet are presented. Coherent imaging theory is used to determine the coupling efficiency into the fibre and thence the fibre numerical aperture is defined and used to compute the sample size on the sky. A higher degree of tip-tilt correction is shown to be required for coupling into single-mode fibres with a lenslet than the multimode fibre alternative, for sparse sampling integral field and multi-object spectroscopy and interferometry, but the magnitude of which is within the scope of current NIR and planned (extreme) VIS AO systems. Extension of the model to contiguous integral field spectroscopy is also considered. 相似文献
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James E.H. Turner Bryan W. Miller Tracy L. Beck Inseok Song Andrew J. Cooke Robert L. Seaman Francisco G. Valds 《New Astronomy Reviews》2006,49(10-12):655
We present a brief overview of facilities for Integral Field Spectroscopy at the Gemini Observatory. These include four optical and near-infrared IFUs suitable for high spatial resolution work and a suite of tasks for handling IFU data in the Gemini IRAF package. We describe the tools for data reduction that are available now or planned in the near future, helping investigators make productive use of these ground-breaking instruments. Further details on the individual IFUs, specific science applications and reduction examples are given in associated presentations by Beck et al., Carrasco et al., Trancho et al. and Winge et al. 相似文献
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Remko Stuik Roland Bacon Ralf Conzelmann Bernard Delabre Enrico Fedrigo Norbert Hubin Miska Le Louarn Stefan Strbele 《New Astronomy Reviews》2006,49(10-12):618
MUSE, the Multi-Unit Spectroscopic Explorer, is an adaptive optics (AO)-assisted Integral Field Spectrograph, currently in the Preliminary Design Phase as a second generation instrument for the VLT. MUSE will feature two modes, each with an associated AO mode. The first mode is the wide field mode, mainly aiming at the study of high redshift galaxies. For this mode, the AO system has to deliver an improvement of at least a factor of two over the full 1′ × 1′ field of view. The second mode, the narrow field mode, aims at the high-resolution spectroscopy of nearby extended objects, for example, galaxies and globular clusters. For this mode, the AO system will have to deliver near-diffraction limited performance over a small field of view. In this paper, we discuss the trade-offs in the current design of GALACSI – the MUSE AO system – and illustrate with a number of simulations the expected performance in the wide- and narrow field modes. 相似文献
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Area spectroscopy has significant advantages over both traditional imaging and long-slit spectroscopy: it is more efficient
in observing time, and yields substantially more information. Through Integral Field Units, area spectroscopy is becoming
an essential part of new facility instruments on the latest large telescopes. We have been undertaking a programme on the
Gemini 8-m telescopes to demonstrate the power of integral field spectroscopy, using the optical GMOS spectrograph, and the
new CIRPASS instrument in the near-infrared. Here we present some preliminary results from 3D spectroscopy of z ∼ 1 objects, mapping the emission lines in a 3CR radio galaxy and in a gravitationally lensed arc.
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献
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Peter McGregor Michael Dopita Ralph Sutherland Tracy Beck Thaisa Storchi-Bergmann 《Astrophysics and Space Science》2007,311(1-3):223-230
We present first results from the Near-infrared Integral Field Spectrograph (NIFS) located at Gemini North. For the active
galaxies Cygnus A and Perseus A we observe rotationally-supported accretion disks and adduce the existence of massive central
black holes and estimate their masses. In Cygnus A we also see remarkable high-excitation ionization cones dominated by photoionization
from the central engine. In the T-Tauri stars HV Tau C and DG Tau we see highly-collimated bipolar outflows in the [Fe II]
λ 1.644 micron line, surrounded by a slower molecular bipolar outflow seen in the H2 lines, in accordance with the model advocated by Pyo, T.-S., et al., Astrophys. J. 570, 724 (2002). 相似文献
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In this paper, we describe the capabilities of E3D, the Euro3D visualization tool, to handle and display data created by large Integral Field Units (IFUs) and by mosaics consisting of multiple pointings. The reliability of the software has been tested with real data, originating from the PMAS instrument in mosaic mode and from the VIMOS instrument, which features the largest IFU currently available. The capabilities and limitations of the current software are examined in view of future large IFUs, which will produce extremely large datasets. (© 2004 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim) 相似文献
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Paulo J.V. Garcia 《New Astronomy Reviews》2006,49(10-12):590
We review the contribution of integral field spectroscopy (IFS) to pre-main-sequence star studies. These studies are mostly synoptic in nature reflecting the use of this technique in addressing difficult and complex objects. Physical diagnostics were derived from IFS data such as (atomic, molecular) gas excitation and pre-shock densities, gas morphology and spectra from close binaries. Models for the sources are directly tested: shock models (planar, bow-shock) and magneto-hydrodynamics jet models.Future contributions to the field are addressed. Surveys of mass loss across age and mass spectrum and in the nearby Orion Nebula cluster emerge as the most scientifically promising. 相似文献