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中国科学院国家天文台科研人员提出新型构建银河系电子三维分布方法（图）
银河系 电子三维 分布方法
2023/1/11
研究人类居住的太阳系附近的银河系环境、构成银河系生态系统的多种组份之间的相互作用、超新星爆发等星际活动对地球乃至人类演化的影响等等是天文学领域里的重要话题。这些都依赖于准确绘制银河系的三维物质分布。近日，国家天文台宇宙暗物质与暗能量研究团组提出一种利用超长波观测（在射电天文学领域，超长波或者超低频指频率在30MHz以下的电磁波）来构建银河系电子分布的新方法。这个方法无需对银河系的电子分布做任何先验...
观测表明银河系内存在为数众多的星际泡，泡壁的二维投影亦称壳层，太阳系便位于称之为本地泡的一个泡结构之内。随着越来越多星际泡的发现和确认，人们对泡的研究渐趋深入，包括泡结构的多种统计性质，星际泡的若干可能的形成机制，以及泡与恒星形成和演化的关系等。从上述诸方面介绍了银河系泡结构的多波段研究进展。
Measurement of Galactic Logarithmic Spiral Arm Pitch Angle Using Two-Dimensional Fast Fourier Transform Decomposition
Galactic Logarithmic Spiral Arm Pitch Angle Two-Dimensional Fast Fourier Transform Decomposition
2012/2/23
A logarithmic spiral is a prominent feature appearing in a majority of observed galaxies. This feature has long been associated with the traditional Hubble classification scheme, but historical quotes...
I show that, in the context of MOND, non-isothermal models, approximated by high order polytropic spheres, are consistent with the observations of the radial distribution of the line-of-sight velocity...
Evolution of star clusters in arbitrary tidal fields
globular clusters: general – open clusters and associations: general – galaxies: star clusters – methods: analytical – methods: numerical
2011/10/20
We present a novel and flexible tensor approach to computing the effect of a time-dependent tidal field acting on a stellar system. The tidal forces are recovered from the tensor by polynomial interpo...
Enriched haloes at redshift $z=2$ with no star-formation: Implications for accretion and wind scenarios
galaxies:evolution galaxies:formation galaxies:high-redshifts galaxies
2011/10/13
In order to understand which process (e.g. galactic winds, cold accretion) is responsible for the cool (T~10^4 K) halo gas around galaxies, we embarked on a program to study the star-formation propert...
R-Process Nucleosynthesis in Dynamically Ejected Matter of Neutron Star Mergers
Nucleosynthesis Dynamically Ejected Matter Neutron Star Mergers
2011/9/28
Although the rapid neutron-capture process, or r-process, is fundamentally important for explaining the origin of approximately half of the stable nuclei with A > 60, the astrophysical site of this pr...
Advanced Morphological Galaxy Classification: A Comparison of Real and Simulated Galaxies
galaxies: structure — galaxies: evolution — methods: numerical
2011/10/18
Encoded within the morphological structure of galaxies are clues related to their formation and evolutionary history. Recent advances pertaining to the statistics of galaxy morphology include sophisti...
The Galactic dust-to-metals ratio and metallicity using gamma-ray bursts
Gamma-ray burst: general – ISM: abundances – dust, extinction – Galaxy: abundances – X-rays: ISM
2011/10/18
The metallicity and dust-to-metals ratio of the Galaxy are fundamental parameters in understanding the ISM, but there is still uncertainty surrounding these parameters. In this paper, the dust-to-meta...
Young stellar groups in M 33 galaxy: delineation and main parameters
Young stellar groups in M 33 galaxy: delineation and main parameters
2011/10/18
The problem of (non-)existence of a typical size of the stellar associations is revisited by use of deep UBVRI stellar CCD photometry in M 33 from the Local Group Survey (Massey et al. 2006). We compa...
Two generations in stellar complexes and associations in M 33 galaxy and their spatial correlation
generations stellar complexes associations galaxy spatial correlation
2011/10/18
Massive stellar content of stellar complexes and associations in M 33 is studied combining deep UBV photometry from the Local Group Survey (Massey et al. 2006) and JHK photometry from the 2MASS. Two b...
A Study of Gravitational Lens Chromaticity with the Hubble Space Telescope
A Study of Gravitational Lens Chromaticity with the Hubble Space Telescope
2011/10/20
We report Hubble Space Telescope observations of 6 gravitational lenses with the Advanced Camera for Surveys. We measured the flux ratios between the lensed images in 6 filters from 8140\AA\ to 2200\A...
A new Monte Carlo method has been developed in order to derive ages of young embedded clusters within massive star forming regions where there is strong differential reddening. After foreground and in...
The Spitzer ice legacy: Ice evolution from cores to protostars
Spitzer ice legacy Ice evolution cores protostars
2011/10/20
Ices regulate much of the chemistry during star formation and account for up to 80% of the available oxygen and carbon. In this paper, we use the Spitzer c2d ice survey, complimented with data sets on...
Complex molecules toward low-mass protostars: the Serpens core
Complex molecules low-mass protostars Serpens core
2011/10/20
Gas-phase complex organic molecules are commonly detected toward high-mass protostellar hot cores. Detections toward low-mass protostars and outflows are comparatively rare, and a larger sample is key...