共查询到19条相似文献，搜索用时 109 毫秒
1.
暗云L1211的C^18O（J=1—0）分子发射谱线的观测 总被引：1，自引：1，他引：0
本文作者首次对暗云Ｌ１２１１的Ｃ＾１８Ｏ（Ｊ＝１－０）分子发射谱线进行了观测，发现了暗云Ｌ１２１１致密核的Ｃ＾１８Ｏ（Ｊ＝１－０）的宽翼发射谱线和它的结构，得到了核区Ｃ＾１８Ｏ（Ｊ＝１－０）分子的谱线轮廓图、强度分布图、速度分段积分等高图、速度位置图。 相似文献
2.
3.
本文作者首次对暗云Ｌ１２１１的Ｃ~（１８）Ｏ（Ｊ＝１－０）分子发射谱线进行了观测，发现了暗云Ｌ１２１１致密核的Ｃ~（１８）Ｏ（Ｊ＝１－０）的宽翼发射谱线和它的结构，得到了核区Ｃ~（１８）Ｏ（Ｊ＝１－０）分子的谱线轮廓图、强度分布图、速度分段积分等高图、速度位置图。 相似文献
4.
5.
在８０ 年代初,尤峻汉和程富华从理论上证实,当相对论电子在稠密气体中运动时,切伦科夫效应将产生宽的、轮廓明显不对称的原子或分子发射线．此后这一新的谱线发射机制被一系列实验所确证．尤峻汉等人又进一步给出了有关切伦科夫辐射的系列解析公式,但其有关谱轮廓和红移的结论只适用于极稠密的气体．由于这一线辐射机制在天体物理中的潜在重要性,在他们工作的基础上,进一步简化、推广、改进了原有的公式体系,并以天体物理学家熟悉的形式做出了更便于实际应用的表述 相似文献
6.
超新星遗迹(supernova remnant,简写为SNR)在早期阶段的结构和演化是与周围星际介质环境密切相关的,这些星际介质也就成为研究SNR.演化的探针.观测了SN1572方向周围的12CO(J=1-0)谱线,拟调查SN 1572周围CO气体的分布,为研究SN 1572与周围分子气体的关系以及该超新星遗迹的演化提供观测依据.观测结果表明,在视向速度VLSR=-69～-58km s-1范围内的CO分子气体与SN 1572成协,此速度成分来自一个大尺度分子云.分子气体沿着SNR的射电壳边缘连续地但非均匀地分布,形成一个包围着SNR的半封闭的分子壳层.整个东半边有着增强的发射,尤其是东北边缘处的CO发射最强.峰值发射位置的谱线呈致宽(>5km s-1)的速度特征,结合光学,红外、X-射线等其它波段在对应位置上的已有观测,都表明了快速的激波和抛出物质正膨胀进入东北边缘的分子气体中,与稠密的气体发生相互作用.这种相互作用将对SN 1572今后的演化有着重要的影响. 相似文献
7.
本文从Ⅰ型Seyfert星系在双色图上的行为出发,假定可见光与紫外波段连续谱的主要成分包括幂律非热致辐射、黑体辐射、宽线区Balmer连续谱的复合辐射和高阶Balmer线辐射,计算了这些发射机制的参数,发现结果与从分光光度测量决定的参数符合很好。因此,本文结果对已测定色指数的Ⅰ型Seyfert星系可决定出其热致成分(黑体谱和Balmer连续谱)在全部辐射中占的比重;给出了研究类星体的可见光与紫外波段辐射机制的新方法。 相似文献
8.
1986年3—4月间,哈雷彗星的日心距为1和1.5 A.U.附近。我们使用云南天文台1米RCC望远镜和卡焦摄谱仪,取得了7张长狭缝光谱。这是我国唯一的一组哈雷彗星长狭缝光谱。光谱色散度为165(?)/mm,分辨率不小于7(?)。本文主要给出6张Kodak 103_a-O底片上3000—5100(?)波段的谱线证认结果。光谱片上主要出现了CN、C_2、C_3、CH、NH、OH等分子发射线,还可能存在NH_2、CH~+、N、H_2CO等发射线。光谱中连续辐射、吸收线较强,离子谱线少而弱,表明哈雷彗星是富尘的。OH(3090)发射线的出现既证实了卫星观测结果,又说明云南天文台的紫外观测条件是优越的。 相似文献
9.
邓铁如 《中国天文和天体物理学报》1996,(3)
围绕黑洞作开普勒运动的环状发光物所发射的光，将受到多普勒颇移和引力的综合作用．本文用光子输运方程方法，针对洛仑兹型发射谱线，求出在Schwarzschild度规下谱线轮廓的精确解，并讨论了Hercules星系团中类星体1604＋179光谱的认证． 相似文献
10.
斐春伟 《紫金山天文台台刊》1997,16(1):1-5
使用名古屋大学４米毫米波射电望远镜于１９９５年１月对对分子云ＯＲＩＯＮ－ＩＬ区域的ＣＨ３ＣＮＪｋ＝６ｋ－５ｋ谱线进行了观测，得到了该区域的５点的谱线。该谱线的观测为青海站１３．７米毫米波射电望远镜提供了又一条可供观测的分子谱线。 相似文献
11.
《Chinese Astronomy and Astrophysics》1987,11(1):20-24
We propose to interpret the nonthermal emission lines of molecular clouds by a Cerenkov radio line emission mechanism. Relativistic electrons passing through a cloud with population inversion can generate microwave emission lines of anomalous intensity ratios. Calculations for nonthermal emission lines of OH sources of Group I Ia associated with supernova remnants show that this nonthermal mechanism may provide a hopeful way of solving certain difficulties of the theory of celestial masers. 相似文献
12.
We have measured the line widths and nonthermal velocities in 12 solar regions using high resolution EUV data taken by Hinode/EIS. We find that there exists a positive correlation between the intensity and nonthermal velocity for the Fe XII emission line as well as some other lines. The correlation coefficients decrease from the disk center to the limb. However, the nonthermal velocities of a particular spectral line do not vary much in different regions, so they are considered isotropic. In particular, we find that for a coronal loop structure, the largest widths and nonthermal velocities occur at the footpoints, where outflows appear. Based on these observational results, we discuss several physical processes responsible for coronal heating. 相似文献
13.
The 10.86-μm P(44) and 10.33-μm R(8) lines of 12C16O2 were observed on Venus with an infrared heterodyne spectrometer. The spectral resolution equals the Doppler half-width and the line profiles are fully resolved. The P(44) line was observed in June 1979 on the day side of the planet. The P(44) line core appears in absorption; the nonthermal core emission, which is present at low J values, is negligible at J = 44. Modeling of the line profile indicates that a discrete, optically thick, cloud deck occurs at 45 mbar pressure, in essential agreement with current understanding of the Venusian cloud structure. The 10.33-μm R(8) line was observed in April 1980 at a variety of positions on the day side, and at a single position on the night side. The strong nonthermal core emission which appears on the day side for this line is not present on the night side, where the line core appears in absorption. This behavior is consistent with a solar radiative pump as an excitation mechanism for the nonthermal emission. Modeling of the R(8) night-side profile indicates that substantial high-altitude haze occurs above the cloud tops, in the region from 15 to 35 mbar pressure. Comparing the modeling for the R(8) line to the P(44) line we find that the variation in the mass of the high-altitude haze was greater than a factor of 2. 相似文献
14.
在中子星磁轴吸积柱的上部,少数高能电子通过磁镜点反射,可使部份电子的速度分布形成非热分布,由此激发激射(Maser)不稳定性。波被放大,发射出频率近似为电子迴旋频率及其倍频的相干辐射。用此模型计算了HerX-1的迴旋线发射。发现不稳定性增长率与吸积柱中电子数密度成正比,因而比非相干散射产生的连续辐射随电子数密度增长更快;而且发射线的强度和能量均与脉冲相位关联。这个理论可解释近期的HerX-1观测结果。 相似文献
15.
Leif Holmlid 《Astrophysics and Space Science》2006,305(1):91-98
The detailed processes giving maser line radiation from various molecules in space are not well understood, as can be seen from many recent detailed studies of maser line emission with high spatial and velocity resolution, and with polarization measurements. We now propose an improved maser mechanism based on amplification of the original molecular line emission by stimulated emission in Rydberg Matter (RM) clouds in HII regions, containing clusters H
N
and (H2)
N
. This mechanism will amplify the molecular lines, depending on the position, velocity, cluster size and state of excitation of the clusters in the RM cloud. RM will only support certain frequencies, corresponding to rotational transitions of the clusters. The bond lengths in the RM clusters are known within 1% from radio frequency emission measurements in the laboratory, and it is now shown that all the commonly studied maser lines agree well with stimulated emission transitions in several types of RM clusters simultaneously. This may explain the strongly varying intensities of neighboring or related maser lines, an important effect that is not well understood previously. It is also pointed out that the magnetic field due to RM is of the same order of magnitude as observed from the Zeeman splitting in maser lines; thus, the molecules that are the original sources of the lines may be embedded in the RM clouds, for example in dense HII regions that are likely to be RM regions. 相似文献
16.
Tetsuya Watanabe 《Solar physics》1990,126(2):351-366
This paper analyzes soft X-ray spectra obtained from the Hinotori spacecraft for the investigation of plasma motions during the initial phase of the great flare, 1982 June 6. The wavelength calibration of the scanning spectrometers is determined from information on the spacecraft attitude and from the position of the Fexxv resonance line during the decay phase. Hard X-ray bursts, nonthermal line broadenings and blueshifted components in X-ray lines are temporally correlated with time differences of 0–30 s. The possible contribution of the blueshifted component to the line width decreases more rapidly than the nonthermal broadening, which suggests dominant plasma motions are taking place at higher and higher altitude in the corona, because of the increase of electron density in flaring loops. The evolution of the input kinetic energy content to the thermal plasma inferred from line broadenings in the impulsive phase resembles that of the thermal energy content in the source of the Fexxvi emission, which is different from that deduced for Fexxv source. This suggests that the origins of the nonthermal line broadening and Fexxvi source are closely coupled. 相似文献
17.
A. M. Zodi E. Correia J. E. R. Costa P. Kaufmann S. F. Martin M. R. Kundu 《Solar physics》1988,116(1):83-89
We present radio maps at 22 and 44 GHz which show the emission before and after the eruption of a quiescent prominence located at the west limb. The observed radiation following the eruption is not consistent with thermal bremsstrahlung mechanism. It can be interpreted as due to gyrosynchrotron emission of nonthermal electrons. Our observations appear to be similar to the microwave radiation observed in post-flare loops; this radiation is due to nonthermal electrons trapped in the closed magnetic structures formed after the prominence eruption. 相似文献
18.
Eberhard Haug 《Solar physics》1979,61(1):129-142
The energy distributions of nonthermal electrons are derived from hard X-ray spectra taken during the impulsive phase of two 2B flares in February 1969. They are used to calculate the fluxes of nonthermally excited X-ray lines of hydrogen-like and helium-like ions. These fluxes are compared to the total line fluxes observed at the same time with crystal spectrometers. The nonthermal excitation is found to give only small contributions to the total line intensities. This implies that the impact polarization which is to be expected for anisotropic velocity distributions of the energetic electrons, will be low. Nevertheless it should be feasible to detect line polarization during the impulsive phase of strong X-ray flares.NAS/NRC Research Associate. 相似文献
19.
The purpose of this paper is to investigate the crossing point of the power-law distribution lines calculated during different times of microwave and hard X-ray bursts. A linear correlation between the logarithm of the total density and the energy index of nonthermal electrons described by a power-law is proven to be a necessary condition for the crossing of a group of power-law distribution lines corresponding to the time evolution of the nonthermal electrons during a solar microwave and HXR burst. The common crossing point of these lines may be considered as evidence of a common cutoff energy of the nonthermal electrons responsible for gyrosynchrotron or bremsstrahlung radiation. When the common crossing point is close to the low-energy cutoff, the correlation coefficient is negative, and vice versa. The result may be useful for estimating the cutoff energy as well as the particle acceleration mechanism. 相似文献