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1.
本文根据1980年2月至1989年11月期间SMM卫星的硬X射线暴观测和GOER卫星珠卫星际质子积分流量Fp观测,证认出48个共同样品,统计发现HXR暴的寿命TD,峰值记数率Fx和爆发期间射的总光子数C的对数值,与行星际质子积分流量(初归一到耀斑本地)值Fp的对数值之间,均具有特别显著的线性关系,其中以logFp与logC的线性关系的最好,其拟合方程是logFp=-6.04+0.538logC,相  相似文献   

2.
周树荣 《天文学报》1999,40(2):149-155
统计分析了太阳质子事件与微波爆发和软X射线(SXR)耀斑间的关系.结果表明:质子事件的峰值流量与微波爆发和SXR耀斑的峰值流量、能通量间呈正的对数线性相关,相关系数0.7—0.8.根据这一统计结果和观测的微波爆发、SXR耀斑的有关物理量,可以估算伴随的质子事件峰值流量.太阳质子辐射、SXR耀斑和微波爆发三者间的共生关系,可以用磁环中耀斑产生的磁流体动力学过程来解释.大约33%的质子事件没有对应的Ⅱ型爆发,这表明高能质子的加速有随机MHD湍流加速(有Ⅱ型暴)和低频快磁声波湍动加速(无Ⅱ型暴,但有γ射线耀斑)2种不同的加速机制  相似文献   

3.
本文分析了云南天文台10m射电望远镜在2lcm波段上观测到的一次尖峰辐射事件,这次事件发生在5629活动区(S16W109),它伴随了X2·9/SF耀斑及边缘耀斑环,并且有质子流量的上升和一次罕见的地磁场突然反相脉冲与之对应.我们从耀斑环的Hβ照片可以看出,在尖峰辐射发生前,原先存在的耀斑环的顶部开始变亮,而尖峰开始后环顶亮度达到极大,说明这次尖峰辐射与耀斑环顶部增亮有关,辐射很可能来自环顶.从尖峰事件的时间轮廓得到的FFT功率谱表明存在150ms的准周期脉动.按照Mclean等人的模型,即脉动是由俘获在磁通管内的电子的径向振荡引起,可以推断,这次尖峰辐射与Fermi机制激发快速电子有关,且尖峰的发生需要被俘获的电子.此外,我们将这次尖峰事件分解为几百个元耀斑爆发(EFB),并且讨论了这些EFB的性质.  相似文献   

4.
周树荣 《天文学报》1996,37(1):60-67
本文介绍了高空间分辨率的太阳射电观测流量的归算方法,即对观测的太阳天线温度值作天线功率方向图K因子的修正,即可得到太阳射电流量值.文中推导了不同温度分布模型下的K因子表达式,并计算了日面宁静太阳流量值和部分射电源的SVC辐射流量值.对日面宁静区的射电辐射而言,因K的年变化(0.0236—0.0252)不大,因此按其平均值0.0244可计算出22GHz频率上宁静太阳流量s。=0.15Ta。(以sfu为单位,Ta。是宁静区辐射的太阳天线温度),相应的宁静太阳温度为10100土300K.1990年7月2日源区的SVC辐射计算结果表明:日面源区的SVC辐射总和为20sfu,约占日面总辐射的2.4%.  相似文献   

5.
分析RXTE卫星PCA探测器对CygX-1的观测数据,得到了其处于高态及高低高转换时的X射线短时标爆发(Shot)结构。在所观测到的三种态中是不对称的,并且不同的状态中Shot的结构有明显差异。Shot前后沿可分别由双指数函数近似拟合。Shot中的快时变过程是由慢的上升前沿和快的下降后沿构成。在所观测态中Shot平均宽度约为0.11秒(FWHM),比低态时的宽度窄。同一状态中高能段的Shot宽度较  相似文献   

6.
简述了DTM94大气模型,并以其旧版本DTM78为对照进行了初步考察和分析,其中给出了两种模型的大气密度随地磁指数kp,和太阳辐射流量(SolarRadioFlux)变化的情况,并对20d(天)弧长Ajisai卫星的全球SLR观测资料进行处理,结果表明DTN94对近地卫星Ajisai的精密定轨是十分有利的。  相似文献   

7.
丽江高美古天文候选点的视宁度观测   总被引:1,自引:0,他引:1  
介绍了1995年3月至1996年3月在云南丽江天文候选点的视宁度观测结果。全年每日23h至00h,平均R0为15.75cm(FWHM0.698")。其中最好的整夜平均R0为22.41cm(FWHM0.49")。  相似文献   

8.
尤建圻 《天文学进展》1999,17(4):299-308
近年来Yohkon,SOHO和Ulysses等飞船的上天大大提高了日冕观测的范围和精度。如SOHO上的LASCO使日冕可观测范围扩展到1.1-30R并有分光能力;Ulysses则可以取得黄道面外各纬度处的太阳风实地观测数据。这些资料为日冕物态研究提供了大量有用信息:Yohkoh的软X射线观测发现了大尺度冕环重联的证据;  相似文献   

9.
简述了DTM94 大气模型, 并以其旧版本DTM78 为对照进行了初步考察和分析, 其中给出了两种模型的大气密度随地磁指数kp 和太阳辐射流量(Solar Radio Flux) 变化的情况, 并对20d ( 天) 弧长Ajisai 卫星的全球SLR观测资料进行处理, 结果表明DTN94 对近地卫星Ajisai 的精密定轨是十分有利的。  相似文献   

10.
1 ObservationalvelocityfieldWeanalyseHβspectraobtainedatYunnanObservatorywiththetwo dimensionMulti Wave bandSpectra SpectroHelioGraph (MW SSHG) (XuanandLin 1 993) .ThePFLsappearedat0 1 :0 4UTofAugust 1 7,1 989onthewesternsolarlimbabovethelargeactiveregion (AR 5 6 2 9,S1 5°;W 1 …  相似文献   

11.
The advent of new and better instruments in space has resulted in a considerable increase in the number of solar gamma-ray events (GRE) detected. In this paper, we analyze available SMM/GRS and GRANAT/PHEBUS data on the hard X-ray and gamma-ray events, and their associations with solar proton events (SPE) at the Earth's orbit, for the observation period of 1980–1995. About 58% of the GREs under study were found to be SPE-related ones. Size (frequency) distributions have been obtained, for the first time, for the events with different types of emissions (bremsstrahlung, narrow GR lines, positron annihilation line, neutron capture line, SPEs, etc.). We discuss the possible relationships between size distributions implied by the parameter correlation. The distribution for GR events turns out to be generally harder than that for X-ray bursts. The GREs involving energetic particles in space are shown to have a harder frequency distribution in comparison with that for GREs without detectable SPEs. There is also a tendency for the GREs with highest fluences to be related with SPEs. Finally, no correlation seems to exist between the GRL fluence and maximum flux of >10 MeV protons near the Earth.  相似文献   

12.
We consider temporal, spectral, and polarization parameters of the hard X-ray and gamma-ray radiation observed during the solar flare of May 20, 2002, in the course of experiments with the SONG and SPR-N instruments onboard the Coronas-F spacecraft. This flare is one of the most intense gamma-ray events among all of the bursts of solar hard electromagnetic radiation detected since the beginning of the Coronas-F operation (since July 31, 2001) and one of the few gamma-ray events observed during solar cycle 23. A simultaneous analysis of the Coronas-F and GOES data on solar thermal X-ray radiation suggests that, apart from heating due to currents of matter in the the flare region, impulsive heating due to the injection of energetic electrons took place during the near-limb flare S21E65 of May 20, 2002. These electrons produced intense hard X-ray and gamma-ray radiation. The spectrum of this radiation extends up to energies ≥7 MeV. Intense gamma-ray lines are virtually unobservable against the background of the nonthermal continuum. The polarization of the hard X-ray (20–100 keV) radiation was estimated to be ≤15–20%. No significant increase in the flux of energetic protons from the flare under consideration was found. At the same time, according to ACE data, the fluxes of energetic electrons in interplanetary space increased shortly (~25 min) after the flare.  相似文献   

13.
The paper summarizes observations of solar and space phenomena related to the McMath region Number 8461 which passed over the solar disk during the 1966 Proton Flare Project period, from August 21 to September 4, and produced two important solar particle events on August 28 and September 2. The most important results are reviewed and interpretation of some of them is suggested.Items of particular interest: Occurrence of proton-active regions when two or more rows of activity approach each other (Section 3). Possible stimulation of activity by magnetic fields of decaying regions that had been active before (4.2a, 5.1a). Significantly increased correlation of flares with X-ray bursts during the proton-active transit of the region (5.3b). Striking difference in the flare response in radio frequency range before and after August 26 (5.2b). Hardening of the X-rays (5.3a), increase in radio flux (5.2a), change in sunspot configuration (5.1c), and increased capability of the region for particle acceleration (5.1b, 5.2b), starting about three days prior to the proton flare. Clear evidence that some flares that occurred on or after August 26, but prior to the proton flare of August 28, already were sources of 1 MeV protons (5.2b, 8). Anomalous deficiency in metric component of radio bursts produced in the region (5.2c, 9.4d, 11.4b). Strong radio storm on meter waves immediately preceding the proton flare on August 28 (5.2a, 9.1b), coincident with preflare rising dark filament (9.1a) and slight preflare rise in flux of 1 MeV protons (10.2). Two phases of expansion (fast and slow) of the bright flare ribbons (9.2c). Coincidence of hard X-ray burst with the formation and fast separation of the bright flare ribbons. It is suggested that this is the time of particle acceleration in the flare (9.5b). Short-lived burst of UV radiation (9.6). Visible flare wave in the flare of August 28 (9.3b), and complexity of motions in this flare (9.4b). Suggested electron release by means of a blast wave (10.1a). Electron-proton splitting in the delayed shock-wave-associated maximum of the particle flux on August 29 (10.2c). First brightening of both proton flares in a similar position between the regions 8461 and 8459 (11.2c). Existence of a unique, low elevation coronal condensation three days after proton flare occurrences (7.2). Very strong flux of protons in energy range of the order of 100 MeV producing the largest PCA since July 1961, and unusually steep energy spectrum above 100 MeV in the flare of September 2 (12.2a, b, 12.4). Unusually long rise to the maximum flux, inconsistent with Burlaga's theory of anisotropic diffusion (12.2b). Interpretation of the undisturbed flux decay from September 2 to September 8 (12.2c). A corotating modulation phenomenon on September 8 (12.2d). Detection of medium nuclei, with He/M ratio 50 ± 11 (12.3a). Evidence against a purely velocity-dependent mode of particle propagation (12.3b). Electrons as the possible cause of the first PCA phase (12.4). Plasma disturbance due to permanent proton flux from the region (13.1). Electron injection into inner radiation belt during the geomagnetic storm associated with the September 2 flare (13.3).Section 14 brings a time scheme of the most important phenomena associated with the complex of activity and the active region in question, and some unsolved problems of particular interest are pointed out in Section 15.  相似文献   

14.
The correlation between the proton flux intensity I p with the energies E p > 1?100 MeV and radio burst parameters for 107 solar energetic events is considered using the observation data for 1989?C2005 obtained with GOES and Wind satellites, as well as the Radio Solar Telescope Network (RSTN). It has been revealed that 73 and 77% of the events were accompanied by type-II radio bursts in the meter (m II, 25?C299 MHz) and the decameter-hectometer (DH II, 20 kHz?C14 MHz) wavelength ranges, respectively. The correlation coefficient between I p and the frequency drift velocity of the type-II bursts V II did not exceed 0.40. As V II increased, the intensity of I p increased for the m-II bursts and decreased for the DH-II bursts. Coronal shock waves accelerate protons more efficiently than interplanetary waves, and their contribution to acceleration increases with an increase in the particle energy E p . The acceleration of solar energetic particles in the region of the flare energy release is predominant.  相似文献   

15.
Energetic proton measurements obtained from the GOES and IMP-8 satellites as well as from ground-based neutron monitors are compared with the GOES soft X-ray measurements of the associated solar flares for the period 1975–2003. The present study investigates a broad range of phenomenology relating proton events to flares (with some references to related interplanetary disturbances), including correlations of occurrence, intensities, durations and timing of both the particle event and the flare as well as the role of the heliographic location of the designated active region. 1144 proton events of > 10 MeV energy were selected from this 28-year period. Owing primarily to the low particle flux threshold employed more than half of this number was found to be reliably connected with an X-ray flare. The statistical analysis indicates that the probability and magnitude of the near-Earth proton enhancement depends critically on the flare's importance and its heliolongitude. In this study all flares of X-ray importance > X5 and located in the most propitious heliolongitude range, 15W to 75W, were succeeded by a detectable proton enhancement. It was also found that the heliolongitude frequently determines the character of the proton event time profile. In addition to intensity, duration and timing, proton events were found to be related to the other flare properties such as lower temperatures and longer loop lengths.  相似文献   

16.
Das  T.K.  Sarkar  H. 《Solar physics》2002,207(2):381-388
The relationship between metric type II radio bursts and soft X-ray (SXR) flares is studied. Type II bursts are highly associated with SXR flares. The duration and drift rate of type II bursts are found to depend on the duration, asymmetry in duration (ratio of rise time to duration), as well as on the peak flux of SXR bursts. Important results obtained are: (i) the durations of type II bursts are linearly correlated with the durations of associated SXR bursts in case of long-lived events (duration >40 min), whereas in short-lived flares such a correlation is not found, (ii) the durations of type II bursts do not depend upon the SXR peak flux, (iii) more durable type II radio bursts are correlated with more symmetric SXR bursts, (iv) average drift rates of type II bursts are larger in the events associated with more powerful and more symmetric SXR bursts.  相似文献   

17.
We study 27 increases of the flux of 300–800 keV electrons on board HELIOS A or B, associated with intense type III radio bursts close to perihelion passages of the two spacecraft, during the solar minimum. Electrons can be detected inside cones with an angular width between 30° and 60°. Though only intense type III bursts are associated with recognizable electron events in space, such an association does not exist for all of them; this fact and great differences in fluxes of the individual events indicate that, apart from the intensity, also some other charactefistic of the type III burst acceleration or propagation process determines the resulting flux of electrons in space; the energy spectrum of the accelerated electrons is one of the likely candidates. A comparison of the electron flux in these events with the flux of 1.7–3.7 MeV nucl–1 helium reveals very large variations of the helium/electron flux ratio, by a factor of at least 15 and possibly much higher. We demonstrate that these variations are not caused by propagation effects in interplanetary space. Therefore, they must be due either to propagation effects in the solar corona or, more likely, to intrinsic variations in the relative production of electrons and nuclei in the type III burst process. An extrapolation of the observed fluxes to 1 AU shows that in only 7 of the 27 electron events studied might a marginal > 1.7 MeV helium flux be recognized ar the Earth distance.  相似文献   

18.
Kocharov  Leon  Torsti  Jarmo  Laitinen  Timo  Teittinen  Matti 《Solar physics》1999,190(1-2):295-307
We have analyzed five solar energetic particle (SEP) events observed aboard the SOHO spacecraft during 1996–1997. All events were associated with impulsive soft X-ray flares, Type II radio bursts and coronal mass ejections (CMEs). Most attention is concentrated on the SEP acceleration during the first 100 minutes after the flare impulsive phase, post-impulsive-phase acceleration, being observed in eruptions centered at different solar longitudes. As a representative pattern of a (nearly) well-connected event, we consider the west flare and CME of 9 July 1996 (S10 W30). Similarities and dissimilarities of the post-impulsive-phase acceleration at large heliocentric-angle distance from the eruption center are illustrated with the 24 September 1997 event (S31 E19). We conclude that the proton acceleration at intermediate scales, between flare acceleration and interplanetary CME-driven shock acceleration, significantly contributes to the production of ≳10 MeV protons. This post-impulsive-phase acceleration seems to be caused by the CME lift-off.  相似文献   

19.
The anti-coincidence shield of the SIGMA telescope aboard GRANAT provides observations of solar X-ray and -ray bursts in the energy range 200 keV–15 MeV. The characteristics of the experiment are presented here as well as the observations of the solar bursts detected during the first year of operation. Among these events, two of these bursts associated respectively with a limb and a disk flare were observed with significant flux above 10 MeV. Advantage is taken of the experiment large detector area to examine fine time structures even at high energies ( 10 MeV).  相似文献   

20.
Satellite observations of solar proton events with a halo structure or an energetic storm proton event and an SSC are studied. It is pointed out that some SSC events are associated with a decrease in the few MeV cosmic ray fluxes while most are associated with a flux increase. The properties of halo protons and energetic storm protons are compared. It is hypothesized that the two events are similar in origin. The propagation mode of storm particles is discussed. Evidence is presented for a solar, rather than interplanetary origin of storm protons.  相似文献   

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