Radio Spectra of Three Supernova Remnants: G114.3+0.3, G116.5+1.1 and G116.9+0.2

Presented are new images of supernova remnants G114.3 0.3, G116.5 1.1 and G116.9 0.2 (CTB 1) at 408 MHz from the Canadian Galactic Plane Survey (CGPS). We also use the 1420 MHz images from the CGPS in a study of their 408-1420 MHz spectral indices. The flux densities at 408 MHz and 1420 MHz, corrected for flux densities from compact sources within the SNRs, are 12±6 Jy and 9.8±0.8 Jy for Gl 14.3 0.3,15.0±1.5 Jy and 10.6±0.6 Jy for G116.5 1.1, 15.0±1.5 Jy and 8.1±0.4 Jy for G116.9±0.2. The integrated flux density-based spectral indices (Sv∝v-α) areα=0.16±0.41, 0.28±0.09 and 0.49±0.09 for G114.3 0.3, G116.5 1.1 and G116.9 0.2, respectively. Their T-T plot-based spectral indices are 0.68±0.48, 0.28±0.15, and 0.48±0.04, in agreement with the integrated flux density-based spectral indices. New flux densities are derived at 2695 MHz which are significantly larger than previous values. The new 408, 1420 and 2695 MHz flux densities and published values at other frequencies, where images are not available, are fitted after correcting for contributions from compact sources, to derive their multi-frequency spectral indices.     

CO Clouds around SNR G21.8-0.6 and G32.8-0.1

We made the first CO(I—0) mapping to SNR G21.8-0.6 and SNR G32.8-0.1, both associated with OH 1720 MHz maser.Based on the morphological correspondence and velocity and position agreement between the radio remnant and the CO clouds,we tentatively identify the clouds that are respectively interacting with the two SNRs.     

Tilted and non-tilted Gödel-type universe

This paper explores the dynamics of Gödel-type geometry for tilted and non-tilted congruences. The kinematical as well as dynamical quantities are investigated for both congruences with non-vanishing nature of vorticity vector. The obtained vorticity is of kinematical type, i.e., not produced by a circular flow of superenergy on the plane orthogonal to the vorticity vector. We conclude that super-Poynting vector is non-zero for the tilted congruence linked with heat flux of fluid distribution while it vanishes in non-tilted case.     

A Spectral Atlas of F and G Stars

We present an atlas of a group of bright stars in the range of spectral classes F-G and luminosity classes I-V. The spectra were obtained with spectral resolution R ～ 15 000 within spectral region 4500-6620/A Typical spectra of stars with different metallicity [Fe/H] are included. We also show the digital version of the spectral data in FITS format.     

Anisotropic cosmological model with variable G and Λ

Anisotropic Bianchi-III cosmological model is investigated with variable gravitational and cosmological constants in the framework of Einstein’s general relativity. The shear scalar is considered to be proportional to the expansion scalar. The dynamics of the anisotropic universe with variable G and Λ are discussed. Without assuming any specific forms for Λ and the metric potentials, we have tried to extract the time variation of G and Λ from the anisotropic model. The extracted G and Λ are in conformity with the present day observations. Basing upon the observational limits, the behavior and range of the effective equation of state parameter are discussed.     

地球站G/T值的测量

采用分别测量地面天线系统的增益G和接收系统噪声温度T的方法,对几个地球站的G/T值(它是地球站的重要技术指标)进行了测量.结果表明:对4.193 GHz而言,6个地面站的G/T值分别为31.11 dB/k,30.57 dB/k,31.34 dB/k,31.93 dB/k,31.42 dB/k和31.26 dB/k,达到了国际通讯卫星组织颁布的F2类地球站的标准.     

红外暗云G79.2+0.38的性质

对MSX红外暗云G79.2+0.38的11'×7'的区域范围进行了12CO(1-0)、13CO(1-0)和C18O(1-0)谱线的同时观测.观测到的两个C18O(1-0)谱线所界定的云核峰值分布分别对应MSX A波段的两块高消光区域.该区域的氢分子柱密度N(H2)-(5-12)×1022 cm-2,平均密度n-(3±1)×104cm-3.两块分子云核的13CO的线尺度分别是1.7和1.2 pc,而C18O的线尺度分别是1.2和0.6 pc,它们包含的质量为2×102-2×103M(?).分子云核的视向平均密度结构可用幂函数(?)(p)-p-0.34±0.02表征. 13CO和C18O的丰度和典型的光学暗云相比低了4至11倍,但是目前还没有证据表明13CO和C18O的相对丰度比X13/18随柱密度有显著变化.     

太阳附近F和G矮星的金属含量统计

收集了一个新的较为完备的太阳附近25pc内的F,G矮星样本,利用最新的窄带测光资料和定标关系导出了148颗F矮星和382颗G矮星的金属含量的分布,讨论了对银河系化学演化的意义。     

关于北斗G2卫星的溯往追终

2022年1月, 失效的北斗G2卫星被实践21号卫星从地球静止轨道拖入了坟墓轨道. 为了这项捕获任务的安全实施, 需要预先确定北斗G2的旋转状态. 基于过去10 yr的测光观测数据展示了北斗G2卫星自转的演化过程. 根据北斗G2的自转速度和轨道的演化, 确认了在过去的10 yr里发生的6次异常事件. 据推测, 2012年的小碎片碰撞事件, 是随后几年燃油泄漏的导火索. 2017年之后剩余燃油完全释放, 再也没有出现转速异常. 将2014年太阳能帆板损坏和2016年的解体事件后建立的旋转动力学模型外推1 yr, 转轴的标准偏差小于3°, 转速标准偏差为0.11°· s^-1, 能够有效地满足捕获任务时刻旋转状态的精度要求.     

Mutually interacting tachyon dark energy with variable G and Λ

We consider a tachyonic scalar field as a model of dark energy with interaction between components in the case of variable G and Λ. We assume a flat Universe with a specific form of scale factor and study cosmological parameters numerically and graphically. Statefinder analysis is also performed. For a particular choice of interaction parameters we succeed in obtaining an analytical expression of densities. We find that our model will be stable at the late stage but there is an instability in the early Universe, so we propose this model as a realistic model of our Universe.     

太阳附近G矮星金属含量分布和化学演化

利用新的太阳附近２５ｐｃ内的Ｇ矮星金属含量分布函数,本文在假定星际介质丰度非均匀情况下,讨论了四种化学演化模型的合理性．结果表明,简单模型和坍缩模型与实际情况相差较大,而ＰＩＥ模型和ＰＰＹ模型不仅对金属含量分布函数拟合较好,而且传统的Ｇ矮星问题也可以得到解释．这表明太阳附近可能受银晕影响较小．     

太阳附近G矮星金属含量分布和化学演化

利用新的太阳附近２５ｐｃ内的Ｇ矮星金属含量分布函数，本在假定星系介质丰度非均匀情况下，讨论了四种化学演化模型的合理性，结果表明，简单模型和坍缩模型与实际情况相差较大，而ＰＩＥ模型和ＰＰＹ模型不仅对金属含量分布函数拟合较好，而且传统的Ｇ矮星问题也可以得到解释，这表明太阳附近可能受银晕影响较小。     

G45.07＋0.13羟基分子脉泽的VLBI观测

利用甚长基线干涉仪，在１６６５ＭＨｚ频率上，观测超致密氢ＩＩ区Ｇ４５．０７＋０．１３的左右圆偏振羟基（ＯＨ）分子脉泽辐射．利用多条纹率成图方法，获得了这个区域２０ｍａｓ相对位置精度的脉泽结构图．除两个弱子源以外，所有脉泽子源都位于彗状结构氢ＩＩ区“彗头”的前沿．脉泽团离致密氢ＩＩ区中心投影距离为０＂．４．在完全饱和辐射的假设下，估计脉泽活动区具有氢分子数密度约为４．５×１０８（Ｈ２）ｃｍ－３．在脉泽源中，发现一对Ｚｅｅｍａｎ对，从它们的ＬＳＲ速度差，导出脉泽区的磁场约为３ｍＧ，方向为远离地球方向．在致密氢ＩＩ区Ｇ４５．０７＋０．１３彗头附近的脉泽团的直径为６×１０１６ｃｍ．这与Ｇ３４．０３＋０．２的观测结果很类似．这给解释彗状结构的氢ＩＩ区的各种模型提供了一个可靠的观测约束条件．     

Efficient cosmic-ray production in supernova remnant G347.3–0.5

Broad-band models of the bright NW limb of G347.3–0.5 give convincing evidence that the forward shock of this supernova remnant is accelerating cosmic rays efficiently, placing >25% of the shock kinetic energy flux into relativistic ions. Despite this high efficiency, the maximum electron and proton energies are well below the observed ‘knee’ at ∼10¹⁵ eV in the Galactic cosmic-ray spectrum.     

关于北斗G2卫星的溯往追终

2022年1月,失效的北斗G2卫星被实践21号卫星从地球静止轨道拖入了坟墓轨道.为了这项捕获任务的安全实施,需要预先确定北斗G2的旋转状态.基于过去10 yr的测光观测数据展示了北斗G2卫星自转的演化过程.根据北斗G2的自转速度和轨道的演化,确认了在过去的10 yr里发生的6次异常事件.据推测, 2012年的小碎片碰撞事件,是随后几年燃油泄漏的导火索. 2017年之后剩余燃油完全释放,再也没有出现转速异常.将2014年太阳能帆板损坏和2016年的解体事件后建立的旋转动力学模型外推1 yr,转轴的标准偏差小于3°,转速标准偏差为0.11°·s^-1,能够有效地满足捕获任务时刻旋转状态的精度要求.     

Bianchi type-I cosmological models with time dependent G and Λ

Einstein field equations with variable gravitational and cosmological constants are considered in the presence of perfect fluid for Bianchi type-I universe by assuming the cosmological term proportional to the Hubble parameter. This variation law for vacuum density has recently been proposed by Schützhold on the basis of quantum field estimations in the curved and expanding background. The model obtained approaches isotropy. The cosmological term tends asymptotically to a genuine cosmological constant, and the model tends to a deSitter universe. We obtain that the present universe is accelerating with a large fraction of cosmological density in the form of cosmological term.     

G.国际原子时和本地原子时之差

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G.国际原子时和本地原子时之差

UTC一UTC(k)公刃2年10月2日 叨DS之549 实脸室(nB) NISC 14 JAI℃一11加1 7日 52554 (,) 10一11046 12日 52559 (二) 0一11092 17日 52564 (二) 一l0一11138 22日 52569 (na) 一13一11168 27日 52574 (ns) 一14一11五抖TAI一TA(k)2的2年10月2日 叨D 52549 实验室(ns) Nl习C一108 JAI℃一乃222 7日 52554 (ns)一104一25324 12日 52559 (ns)一1加一25415 17日 52564 (ns) 一98一乃510 22日 5公569 (ns) 一92一25印4 27日 52574 (ns) 一89一25708一摘自(BIPMC][RO田J以T)冷.178G.国际原子时和本地原子时之差 ~~…     

G.国际原子时和本地原子时之差

UTC一UTC(k)20(论年2月 入习D 实验室 付珑祀 JATC 4日 523侧 (二)一19一价卯 14日 52314 (ns)一19一8890 19日 52319 (。)一19一8931 一9一8盯8日心习n豹‘3处2训O才俩以了rl翻酬TAI一TA(k)加健年2月 入习D 实验室 卜n习C J式1℃ 9日 52309 (ns)一172一20513 14日 52314 (ns)一167一加印8 19日 52319 (ns)一162一20714 24日 52324 (朋)一1研一加815。﹃(ns)︸︸-摘自《BIPMCIRO皿消卫T)冷.170G.国际原子时和本地原子时之差~~…