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1.
本文作者用上海天文台的２５米天线和１２．２ＧＨｚ的接收系统，对银道面附近的一个ＨＩＩ区复合体Ｇ１８．２—０．３进行了射电连续谱观测．采用沿源运动轨迹，对观测曲线进行多子源模型拟合的方法，将该复合体中的６个子源从延展的ＨＩＩ区辐射中分离了出来，并导出了每个子源在１２．２ＧＨｚ频率上的流量和角大小．结合外台站在２６９５ＭＨｚ，４７５０ＭＨｚ和１０．５５ＧＨｚ上的流量还得到了这些子源的辐射频谱．分析表明它们具有热辐射性质．对具有射电复合线（Ｈ７６α）资料和角尺度的４个子源导出了它们的电子密度在（１—３）×１０２ｃｍ－３间．此外通过对Ｇ１８．２—０．３复合体子源ＩＲＡＳ资料的分析和模型拟合还得到了每个子源周围冷尘埃的等效黑体温度．其中４个子源并具有ＩＲＡＳ－ＬＲＳ资料．分析它们得到了与该ＨＩＩ区成协尘埃的性质．根据５个子源的ＩＲＡＳ流量、频带以及色改正因子又求出了这些子源在１—５００μｍ间的总红外光度在２×１０４—１０５Ｌ间．它表明与Ｇ１８．２—０．３中各子源成协的新形成星是一些大质量的ＯＢ型星，它们在同一个延展ＨＩＩ区中如此密集证明了大质量星“致密—堆积”形成模式的合理性． 相似文献
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通过对Ｗ３（ＯＨ）区域２２ＧＨzＨ２Ｏ脉泽源的短时间跟踪观测,探测到速度为－５２ ．８Ｋｍ／ｓ子谱的流量密度呈线性下降趋势,变化时村约为１９天。同时也观测到了整个脉泽源的谱线宽度与该子谱的强度之间的相关变化。这些现象可能是由脉泽云之间的相互碰撞导致脉泽抽运率的变化所引起的。 相似文献
3.
使用澳大利亚Ｐａｒｋｅｓ６４ｍ射电望远镜,在五个不同的位置上观测了ＯＨ１７．７２．０附近的弱ＯＨ脉泽源．发现了一个新的弱ＯＨ脉泽源,其峰值速度为５２．５ｋｍ／ｓ．利用二维Ｇａｕｓｓｉａｎ拟合技术,得到了这个源的最佳拟合位置 相似文献
4.
使用澳大利亚Ｐａｒｋｅｓ６４ｍ射电望远镜,在五个不同的位置上观测了ＯＨ１７．７－２．０附近的弱ＯＨ脉泽源,发现了一个新的弱ＯＨ脉泽源,其峰值速度为５２．５ｋｍ／ｓ。利用二维Ｇａｕｓｓｉａｎ拟合技术,得到了这个源的最佳拟合位置。 相似文献
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本项研究给出了17个具有Ⅱ类星际甲醇分子脉泽源的致密氢11区的轫致辐射、尘埃红外辐射和中心年轻恒星Layman辐射的特征．以脉泽的光子发射率和辐射亮温度作为两个主要的辐射抽运约束条件，讨论了Ⅱ类星际甲醇分子脉泽的几种可能的激发机制．我们认为热辐射亮温度为100K与致密氢Ⅱ区成协的红外辐射体很可能是Ⅱ类甲醇脉泽的抽运源． 相似文献
6.
对１９８８年６月２９日云南天文台高时间分辨率射电望远镜观测到的微波超快速吸收现象进行了分析研究。在世界时０７ｈ３８ｍ５０ｓ至０７ｈ３８ｍ５８ｓ超快速吸收现象出现在太阳活动区ＮＯＡＡ／ＵＳＡＦ５０６０上空的４００ＧＨｚ上,而在２８４ＧＨｚ和１４２ＧＨｚ上空出现的是ｓｐｉｋｅ辐射。当时,该活动区呈现出极其活跃的双极磁场位形。在世界时０７ｈ３８ｍ至０８ｈ４７ｍ先后产生了３Ｂ级和２Ｂ级的Ｈα耀斑,并出现了Ｍ６５Ｘ射线爆发。根据电子回旋脉泽谐波吸收峰的特性,我们计算了三个波段的二次、三次谐波的磁场强度,并采用偶极磁场模型进行分析。对于４００ＧＨｚ上出现的超快速吸收现象,可能是产生的三次谐波脉泽辐射,在穿过吸收区时被吸收掉了。 相似文献
7.
太阳微波脉冲事件中原区加热的证据 总被引：1，自引：0，他引：1
本对具有一定空间分辨率（￣４＇）和高灵敏度（０．００４ｓｆｕ）特性的１３．７ｍ射电望远镜，在１．３５ｃｍ（２２ＧＨｚ）波段上观测到的两个脉冲事件前的周期性脉动和吸收现象进行了分析，并认为这种观测特征，可用源区局部区域的加热得到合理解释。 相似文献
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本文对具有一定空间分辨率（～４’）和高灵敏度（０．００４ｓｆｕ）特性的１３．７ｍ射电望远镜，在１．３５ｃｍ（２２ＧＨｚ）波段上观测到的两个脉冲事件前的周期性脉动和吸收现象进行了分析，并认为这种观测特征，可用源区局部区域的加热得到合理解释。 相似文献
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本文作者用澳大利亚Ｐａｒｋｅｓ ６４ｍ射电望远镜观测了ＯＨ１７．７－２．０的拱星ＯＨ脉泽辐射，在观测中共测得了三个峰，其中一个峰是我们新发现的弱源，两个峰是过去发强源，用二维Ｇａｕｓｓｉａｎ拟合我们发现强源位置与一个ＩＲＡＳ点源位置相一致，弱源位置在这个ＩＲＡＳ点源位置的西南方，强源的两个峰的速度位置和峰值流量密度都是比较稳定的。 相似文献
10.
用射电天文联合实验室紫金山天文台青海站１３．７米望远镜，于１９９７年４月对９７个水脉泽源做了ＣＯ（Ｊ＝１－０）的巡测及部分成图观测，结果表明８１个源的谱线适于作成协星体活动分析．经初步证认有外向流候选者３３个，全部为首次给出高速范围．对其轮廓特点及与Ｈ２Ｏ脉泽辐射的关系作了简要讨论．ＣＯ高速气体和Ｈ２Ｏ脉泽的速度范围和峰值速度在多数情况下分别相符，这说明两者的激发可能相关． 相似文献
11.
Laura Schaefer 《Icarus》2004,169(1):216-241
We modified the MAGMA chemical equilibrium code developed by Fegley and Cameron (1987, Earth Planet. Sci. Lett. 82, 207-222) and used it to model vaporization of high temperature silicate lavas on Io. The MAGMA code computes chemical equilibria in a melt, between melt and its equilibrium vapor, and in the gas phase. The good agreement of MAGMA code results with experimental data and with other computer codes is demonstrated. The temperature-dependent pressure and composition of vapor in equilibrium with lava is calculated from 1700 to 2400 K for 109 different silicate lavas in the ONaKFeSiMgCaAlTi system. Results for five lavas (tholeiitic basalt, alkali basalt, Barberton komatiite, dunite, and a molten type B1 Ca, Al-rich inclusion) are discussed in detail. The effects of continuous fractional vaporization on chemistry of these lavas and their equilibrium vapor are presented. The predicted abundances (relative to Na) of K, Fe, Si, Al, Ca, and Ti in the vapor equilibrated with lavas at 1900 K are lower than published upper limits for Io's atmosphere (which do not include Mg). We predict evaporative loss of alkalis, Fe, and Si during volcanic eruptions. Sodium is more volatile than K, and the Na/K ratio in the gas is decreased by fractional vaporization. This process can match Io's atmospheric Na/K ratio of 10±3 reported by Brown (2001, Icarus 151, 190-195). Silicon monoxide is an abundant species in the vapor above lavas. Spectroscopic searches are recommended for SiO at IR and mm wavelengths. Reactions of metallic vapors with S- and Cl-bearing volcanic gases may form other unusual gases including MgCl2, MgS, MgCl, FeCl2, FeS, FeCl, and SiS. 相似文献
12.
《中国天文和天体物理学报》2014,(9)
正Research in Astronomy and Astrophysics publishes original research papers and reviews 011 all liranchcs of astronoiriy and astrophysics.Reviews arc by invitation only.Important new results that require rapid publication can be submitted as a Letter(Letters must be restricted in length 相似文献
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《中国天文和天体物理学报》2014,(10)
正Research in Astronomy and Astrophysics publishes original research papers and reviews on all branches of astronomy and astrophysics.Reviews are by invitation only.Important new results that require rapid publication can be submitted as a Letter(Letters must be restricted in length to 6 printed pages).Authors who submit a paper are expected to be able to certify that the paper is original work, 相似文献
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Laura Schaefer 《Icarus》2005,173(2):454-468
We use chemical equilibrium calculations to model the speciation of alkalis and halogens in volcanic gases emitted on Io. The calculations cover wide temperature (500-2000 K) and pressure (10−6 to 10+1 bars) ranges, which overlap the nominal conditions at Pele (T=1760 K, P=0.01 bars). About 230 compounds of 11 elements (O, S, Li, Na, K, Rb, Cs, F, Cl, Br, I) are considered. The elemental abundances for O, S, Na, K, and Cl are based upon observations. CI chondritic elemental abundances relative to sulfur are used for the other alkalis and halogens (as yet unobserved on Io). We predict the major alkali species in Pele-like volcanic gases and the percentage distribution of each alkali are LiCl (73%), LiF (27%); NaCl (81%), Na (16%), NaF (3%); KCl (91%), K (5%), KF (4%); RbCl (93%), Rb (4%), RbF (3%); CsCl (92%), CsF (6%), Cs (2%). Likewise the major halogen species and the percentage distribution of each halogen are NaF (88%), KF (10%), LiF (2%); NaCl (89%), KCl (11%); NaBr (89%), KBr (10%), Br (1%); NaI (61%), I (30%), KI (9%). We predict the major halogen condensates and their condensation temperatures at P=0.01 bar are NaF (1115 K), LiF (970 K); NaCl (1050 K), KCl (950 K); KBr (750 K), RbBr (730 K), CsBr (645 K); and solid I2 (200 K). We also model disequilibrium chemistry of the alkalis and halogens in the volcanic plume. Based on this work and our prior modeling for Na, K, and Cl in a volcanic plume, we predict the major loss processes for the alkali halide gases are photolysis and/or condensation onto grains. Their estimated photochemical lifetimes range from a few minutes for alkali iodides to a few hours for alkali fluorides. Condensation is apparently the only loss process for elemental iodine. On the basis of elemental abundances and photochemical lifetimes, we recommend searching for gaseous KCl, NaF, LiF, LiCl, RbF, RbCl, CsF, and CsCl around volcanic vents during eruptions. Based on abundance considerations and observations of brown dwarfs we also recommend a search of Io's extended atmosphere and the Io plasma torus for neutral and ionized Li, Cs, Rb, and F. 相似文献
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In this paper, we investigate the dynamics of Born–Infeld (B–I) phantom model in the ω–ω′ plane, which is defined by the equation of state parameter for the dark energy and its derivative with respect to N (the logarithm of the scale factor a). We find the scalar field equation of motion in ω–ω′ plane, and show mathematically the property of attractor solutions which correspond to ω
φ
∼−1, Ω
φ
=1, which avoid the “Big rip” problem and meets the current observations well.
相似文献
19.
In astronomical observations at optical wavelengths, a fast image tracking system can be adopted to reduce the effects of the atmospheric seeing and telescopic tracking error, and therefore improve the observing efficiency. Aiming at the need of astronomical observations, totally 5 kinds of algorithms in two categories were selected to make a comparative study on their accuracies and stabilities under different noise conditions by both numerical experiment and laboratory test. The results indicate that the normalized cross-correlation method and barycenter method have not only a higher accuracy but also a better reliability against interferences, they will be applied to the high-resolution spectrograph of the Xinglong 2.16 m telescope and the scienti?c instruments of the SONG (Stellar Observations Network Group) project, respectively. 相似文献
20.
Marcelo Samuel Berman 《Astrophysics and Space Science》2008,314(1-3):79-82
A combined BCDE (Brans-Dicke and Einstein-Cartan) theory with lambda-term is developed through Raychaudhuri’s equation, for
inflationary scenario. It involves a variable cosmological constant, which decreases with time, jointly with energy density,
cosmic pressure, shear, vorticity, and Hubble’s parameter, while the scale factor, total spin and scalar field increase exponentially.
The post-inflationary fluid resembles a perfect one, though total spin grows, but the angular speed does not (Astrophys. Space
Sci. 312: 275, 2007d).
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