世界各国太阳射电望远镜概况

详细汇总了国内太阳射电望远镜的技术性能及原理框图。收集了部分国外太阳射电望远镜技术指标。对射电望远镜系统参数灵敏度、信噪比、交叉计划隔离度的计算方法作了介绍。     

Scaling-laws of Radio Spike Bursts and Their Constraints on New Solar Radio Telescopestwo

Radio observation is one of important methods in solar physics and space science. Sometimes, it is almost the sole approach to observe the physical processes such as the acceleration, emission, and propagation of non-thermal energetic particles, etc. So far, more than 100 solar radio telescopes have been built in the world, including solar radiometers, dynamic spectrometers, and radioheliographs. Some of them have been closed after the fulfillment of their primary scientific objectives, or for their malfunctions, and thus replaced by other advanced instruments. At the same time, based on some new technologies and scientific ideas, various kinds of new and much more complicated solar radio telescopes are being constructed by solar radio astronomers and space scientists, such as the American E-OVSA and the solar radio observing system under the framework of Chinese Meridian Project II, etc. When we plan to develop a new solar radio telescope, it is crucial to design the most suitable technical parameters, e.g., the observing frequency range and bandwidth, temporal resolution, frequency resolution, spatial resolution, polarization degree, and dynamic range. Then, how do we select a rational set of these parameters? The long-term observation and study revealed that a large strong solar radio burst is frequently composed of a series of small bursts with different time scales. Among them, the radio spike burst is the smallest one with the shortest lifetime, the narrowest bandwidth, and the smallest source region. Solar radio spikes are considered to be related to a single magnetic energy release process, and can be regarded as an elementary burst in solar flares. It is a basic requirement for the new solar radio telescope to observe and discriminate these solar radio spike bursts, even though the temporal and spatial scales of radio spike bursts actually vary with the observing frequency. This paper presents the scaling laws of the lifetime and bandwidth of solar radio spike bursts with respect to the observing frequency, which provide some constraints for the new solar radio telescopes, and help us to select the rational telescope parameters. Besides, we propose a spectrum-image combination mode as the best observation mode for the next-generation solar radio telescopes with high temporal, spectral, and spatial resolutions, which may have an important significance for revealing the physical essence of the various non-thermal processes in violent solar eruptions.     

云台射电频谱仪预研

简要介绍了用于研究分子夭文学的各种射电频谱仪及国内外发展状况,讨论了各种频谱仪的优缺点,最后提出了云台建立射电频谱仪的型式。     

History of solar telescopes

Solar observations have been done with telescopes since their invention—already Galileo looked at the Sun. Despite the Sun’s unusual brightness, telescopes which specialize in solar observations are fairly recent, dating from the late nineteenth century onwards. Today, many solar telescopes have rather little in common with nighttime telescopes. They are adapted to high light flux, a limited range of declination, and to the specifications of solar spectrographs and polarimeters. This paper presents the history of the modern optical solar telescope on the ground and in space, the accompanying evolution of scientific capabilities, and a brief outlook into the future.     

太阳米波和分米波Ⅱ型、Ⅲ型射电暴及其精细结构观测研究进展

太阳米波和分米波的射电观测是对太阳爆发过程中耀斑和日冕物质抛射现象研究的重要观测手段。米波和分米波的太阳射电暴以相干等离子体辐射为主导,表现出在时域和频域的多样性和复杂性。其中Ⅱ型射电暴是激波在日冕中运动引起电磁波辐射的结果。在Ⅱ型射电暴方面,首先对米波Ⅱ型射电暴的激波起源问题和米波Ⅱ型射电暴与行星际Ⅱ型射电暴的关系问题进行了讨论;其次,结合Lin-Forbes太阳爆发理论模型对Ⅱ型射电暴的开始时间和起始频率进行讨论:最后,对Ⅱ型射电暴信号中包含的两种射电精细结构,Herringbone结构(即鱼骨结构)和与激波相关的Ⅲ型射电暴也分别进行了讨论。Ⅲ型射电暴是高能电子束在日冕中运动产生电磁波辐射的结果。在Ⅲ型射电暴方面,首先介绍了利用Ⅲ型射电暴对日冕磁场位形和等离子体密度进行研究的具体方法;其次,对利用Ⅲ型射电暴测量日冕温度的最新理论进行介绍;最后,对Ⅲ型射电暴和Ⅱ型射电暴的时间关系、Ⅲ型射电暴和粒子加速以及Ⅲ型射电暴信号中包含的射电精细结构(例如斑马纹、纤维爆发及尖峰辐射)等问题进行讨论并介绍有关的最新研究进展。     

太阳射电爆发的起因：耀斑或／和日冕物质抛射

本文分析了近二十年来的地面和空间太阳有关观测资料,得出太阳射电爆发的起因为耀斑和／ 或日冕物质抛射（ＣＭＥ） 而不仅仅是耀斑,这将有利于更深刻地了解太阳射电爆发和共生高能现象的物理过程     

First Results from SOHO

SOHO, the Solar and Heliospheric Observatory, is a project of international cooperation between ESA and NASA to study the Sun, from its deep core to the outer corona, and the solar wind. Three helioseismology instruments are providing unique data for the study of the structure and dynamics of the solar interior, from the very deep core to the outermost layers of the convection zone. A set of five complementary remote sensing instruments, consisting of EUV, UV and visible light imagers, spectrographs and coronagraphs, give us our first comprehensive view of the outer solar atmosphere and corona, leading to a better understanding of the enigmatic coronal heating and solar wind acceleration processes. Finally, three experiments complement the remote sensing observations by making in- situ measurements of the composition and energy of the solar wind and charged energetic particles, and another instrument maps the neutral hydrogen in the heliosphere and its dynamic change by the solar wind. This paper reports some of the first results from the SOHO mission. This revised version was published online in July 2006 with corrections to the Cover Date.     

Nonlinear parametric instability and millisecond solar radio spikes

A model of nonlinear parametric instability (NLPI) modulation is suggested to explain the millisecond spikes in solar decimetric radio emission. The radio emission energy will periodically transfer to two other waves, and the intensity of the radio emission will be modified by NLPI processes in the corona, when the matching conditions of three-wave coupling are satisfied. This model can simultaneously explain the duration of spikes, why the millisecond spikes have not been observed in other solar radio emission, and the relation between the duration of the spikes and the intensity and the frequency of the radio emission as well.     

Magnetically-Driven Planetary Radio Emissions and Application to Extrasolar Planets

At least six intense nonthermal planetary radio emissions are known in our solar system: the auroral radio emissions from the Earth, Jupiter, Saturn, Uranus and Neptune, and the radio bursts from the Io-Jupiter flux tube. The former are thought to be driven by the solar wind flow pressure or energy flux on the magnetospheric cross-section, while the latter is a consequence of the Io-Jupiter electrodynamic interaction. Although in the solar wind, the flow ram pressure largely dominates the magnetic one, we suggest that the incident magnetic energy flux is the driving factor for all these six radio emissions, and that it can be estimated in the same way in all cases. Consequences for the possible radio emission from extrasolar planets are examined. ‘Hot Jupiters’, if they are magnetized, might possess a radio emission several orders of magnitude stronger than the Jovian one, detectable with large ground-based low-frequency arrays. On the other hand, `giants' analogous to the Io-Jupiter interaction in the form of a pair star/hot-Jupiter are unlikely to produce intense radio emissions, unless the star is very strongly magnetized. This revised version was published online in July 2006 with corrections to the Cover Date.     

On the S- and B-components of solar radio and X-emission and their relationships to energetic solar events

The slowly varying solar radio and X-ray emissions are considered theoretically and statistically concerning their significance as potential indicators of energy storage processes in active regions leading to large flare-burst events. A correlation analysis has been carried out in order to test different global emission parameters accessable by daily routine measurements regarding their connection with type IV bursts and proton flares. From all investigated quantities systematically best (though not very high) correlations have been verified for both the 3 cm radio and 0–8 Å X-ray fluxes. Increasing correlation coefficients resulted for running averages indicating possible storage processes over several days.There is some evidence favouring the assumption of a small contribution of nonthermal processes to the spectrum of the S-component at burst-active periods which possibly lead to the development of flare-burst instabilities.     

自由能密度上限及毫秒级射电尖峰的“饱和”机制

本文首先介绍了热力学自由能上限的普遍公式及其推导思想,然后应用于非热电子束的具体形式,从而估计太阳射电活动中的毫秒级尖峰辐射的“饱和”能量;在此基础上,进一步为饱和时间问题作一般性的讨论;最后,在把尖峰“饱和”的几种机制进行了比较之后提出:由于尖峰能量远未达到非线性饱和的水平,因此,由某种外部因素(例如加速机制等)所导致的高能电子束的非均匀性可能是一种较为合理的模型。     

Editorial: solar radiophysics—recent results on observations and theories

Solar radiophysics is a rapidly developing branch of solar physics and plasma astrophysics. Solar radiophysics has the goal of analyzing observations of radio emissions from the Sun and understanding basic physical processes operating in quiet and active regions of the solar corona. In the near future, the commissioning of a new generation of solar radio observational facilities, which include the Chinese Spectral Radio Heliograph（CSRH） and the upgrade of the Siberian Solar Radio Telescope（SSRT）, and the beginning of solar observations with the Atacama Large Millimeter/submillimeter Array（ALMA）, is expected to bring us new breakthrough results of a transformative nature. The Marie-Curie International Research Staff Exchange（MC IRSES） “RadioSun” international network aims to create a solid foundation for the successful exploitation of upcoming solar radio observational facilities, as well as intensive use of the existing observational tools, advanced theoretical modeling of relevant physical processes and observables, and training a new generation of solar radio physicists. The RadioSun network links research teams from China,Czech Republic, Poland, Russia and the UK. This mini-volume presents research papers based on invited reviews and contributed talks at the 1st RadioSun workshop in China. These papers cover a broad range of research topics and include recent observational and theoretical advances in solar radiophysics, MHD seismology of the solar corona, physics of solar flares, generation of radio emission, numerical modeling of MHD and plasma physics processes, charged-particle acceleration and novel instrumentation.     

The emission and propagation of ∼ 40keV solar flare electrons

Observations of prompt 40 keV solar flare electron events by the IMP series of satellites in the period August, 1966 to December, 1967 are tabulated along with prompt energetic solar proton events in the period 1964–1967. The interrelationship of the various types of energetic particle emission by the sun, including relativistic energy electrons reported by Cline and McDonald (1968) are investigated. Relativistic energy electron emission is found to occur only during proton events. The solar optical, radio and X-ray emission associated with these various energetic particle emissions as well as the propagation characteristics of each particle species are examined in order to study the particle acceleration and emission mechanisms in a solar flare. Evidence is presented for two separate particle acceleration and/or emission mechanisms, one of which produces 40 keV electrons and the other of which produces solar proton and possibly relativistic energy electrons. It is found that solar flares can be divided into three categories depending on their energetic particle emission: (1) small flares with no accompanying energetic phenomena either in particles, radio or X-ray emission; (2) small flares which produce low energy electrons and which are accompanied by type III and microwave radio bursts and energetic ( 20 keV) X-ray bursts; and (3) major solar flare eruptions characterized by energetic solar proton production and type II and IV radio bursts and accompanied by intense microwave and X-ray emission and relativistic energy electrons.     

Evolvement of microwave spike bursts in a solar flare on 2006 December 13

Solar radio spikes are one of the most intriguing spectral types of radio bursts. Their very short lifetimes, small source size and super-high brightness temperature indicate that they should be involved in some strong energy release, particle acceleration and coherent emission processes closely related to solar flares. In particular, for the microwave spike bursts, their source regions are much close to the related flaring source region which may provide the fundamental information of the flaring process. In this work,we identify more than 600 millisecond microwave spikes which recorded by the Solar Broadband Radio Spectrometer in Huairou(SBRS/Huairou) during an X3.4 solar flare on 2006 December 13 and present a statistical analysis about their parametric evolution characteristic. We find that the spikes have nearly the same probability of positive and negative frequency drifting rates not only in the flare rising phase, but also in the peak and decay phases. So we suppose that the microwave spike bursts should be generated by shockaccelerated energetic electrons, just like the terminational shock(TS) wave produced by the reconnection outflows near the loop top. The spike bursts occurred around the peak phase have the highest central frequency and obviously weak emission intensity, which imply that their source region should have the lowest position with higher plasma density due to the weakened magnetic reconnection and the relaxation of TS during the peak phase. The right-handed polarization of the most spike bursts may be due to the TS lying on the top region of some very asymmetrical flare loops.     

Fast solar electrons,interplanetary plasma and km-wave type-III radio bursts observed from the IMP-6 spacecraft

IMP-6 spacecraft observations of low frequency radio emission, fast electrons, and solar wind plasma are used to examine the dynamics of the fast electron streams which generate solar type-III radio bursts. Of twenty solar electron events observed between April, 1971 and August, 1972, four were found to be amenable to detailed analysis. Observations of the direction of arrival of the radio emission at different frequencies were combined with the solar wind density and velocity measurements at 1 AU to define an Archimedean spiral trajectory for the radio burst exciter. The propagation characteristics of the exciter and of the fast electrons observed at 1 AU were then conpared. We find that: (1) the fast electrons excite the radio emission at the second harmonic; (2) the total distance travelled by the electrons was between 30 and 70% longer than the length of the smooth spiral defined by the radio observations; (3) this additional distance travelled is the result of scattering of the electrons in the interplanetary medium; (4) the observations are consistent with negligible true energy loss by the fast electrons.     

Phase Relationship Between Sunspot Number, Flare Index and Solar Radio Flux

To understand better the variation of solar activity indicators originated at different layers of the solar atmosphere with respect to sunspot cycles, we carried out a study of phase relationship between sunspot number, flare index and solar radio flux at 2800 MHz from January 1966 to May 2008 by using cross-correlation analysis. The main results are as follows: (1) The flare index and sunspot number have synchronous phase for cycles 21 and 22 in the northern hemisphere and for cycle 20 in the southern hemisphere. (2) The flare index has a noticeable time lead with respect to sunspot number for cycles 20 and 23 in the northern hemisphere and for cycles 22 and 23 in the southern hemisphere. (3) For the entire Sun, the flare index has a noticeable time lead for cycles 20 and 23, a time lag for cycle 21, and no time lag or time lead for cycle 22 with respect to sunspot number. (4) The solar radio flux has a time lag for cycles 22 and 23 and no time lag or time lead for cycles 20 and 21 with respect to sunspot number. (5) For the four cycles, the sunspot number and flare index in the northern hemisphere are all leading to the ones in the southern hemisphere. These results may be instructive to the physical processes of flare energy storage and dissipation.     

THE DIRECTIVITY OF SOLAR KILOMETRIC TYPE III BURSTS: ULYSSES–ARTEMIS OBSERVATIONS IN AND OUT OF THE ECLIPTIC PLANE

Comparing the records of the radio spectrographs ARTEMIS (100–500 MHz) on the ground and URAP (1–1000 kHz) on the Ulysses spacecraft, we find that most type III bursts extend from the corona to the solar wind. Using the positions of the associated flares, and assuming an average intensity ratio between these two frequency ranges, we derive for the first time the average radiation pattern of interplanetary type III bursts. We find that at 800 kHz it is shifted east of the radial direction by 30° and has a half-width of about 80° at maximum/10; the shift and width increase towards lower frequencies. Ulysses high-latitude observations show that the cross-section perpendicular to the heliospheric equator is about the same. We interpret these properties by refraction effects in local density gradients.     

Combined Radio and Space-Based Solar Observations: From Techniques to New Results – Preface

The phenomena observed at the Sun have a variety of unique radio signatures that can be used to diagnose the processes in the solar atmosphere. The insights provided by radio observations are further enhanced when they are combined with observations from space-based telescopes. This Topical collection demonstrates the power of combination methodology at work and provides new results on i) type I solar radio bursts and thermal emission to study active regions; ii) type II and IV bursts to better understand the structure of coronal mass ejections; and iii) non-thermal gyro-synchrotron and/or type III bursts to improve the characterisation of particle acceleration in solar flares. The ongoing improvements in time, frequency, and spatial resolutions of ground-based telescopes reveal new levels in the complexity of solar phenomena and pose new questions.     

太阳二维光谱观测研究的进展和展望

论述了太阳二维光谱观测和研究的重大意义，综述了二维光谱观测技术和仪器的进展，特别介绍了应用ＣＣＤ的成像光谱仪的最近发展。文中还介绍了近年来二维光谱观测研究所取得的一些新结果，展望了未来观测技术和课题研究的发展前景。     

日食的射电观测(英)

日食为射电天文提供了一维高空间分辨率太阳射电观测机会．日食射电观测在太阳射电物理的发展上起过重要的作用．文中对日食射电观测的若干重要因素作了介绍和分析．日食射电观测在我国太阳射电天文发展上也起了重要作用．文中简要介绍了在我国组织观测的1958年、1968年、1980年及1987年的太阳射电日食观测及其主要结果．