A model considering gas outflows due to supernova explosions is developed for the star formation and chemical enrichment for the globular clusters (GCs) in the Milky Way galaxy. Through Monte Carlo simulations, the ob...A model considering gas outflows due to supernova explosions is developed for the star formation and chemical enrichment for the globular clusters (GCs) in the Milky Way galaxy. Through Monte Carlo simulations, the observed global properties of GCs can be well reproduced, including the metallicity distribution, no-correlation between cluster masses and galactocentric distances, etc. The predicted mass function of the parent clouds for the observed GCs at present day can be well described as a power law with the index of-1.8, which is consistent with the current observations for the molecular clouds.展开更多
The normalized inclination distributions are presented for the spiral galaxies in RC3.The results show that,except for the bin of 81°-90°,in which the apparent minor isophotal diameters that are used to obta...The normalized inclination distributions are presented for the spiral galaxies in RC3.The results show that,except for the bin of 81°-90°,in which the apparent minor isophotal diameters that are used to obtain the inclinations are affected by the central bulges,the distributions for Sa,Sab,Scd and Sd are well consistent with the Monte-Carlo simulation of random inclinations within 3-σ and Sb and Sbc almost,but Sc is different.One reason for the difference between the real distribution and the Monte-Carlo simulation of Sc may be that some quite inclined spirals,the arms of which are inherently loosely wound on the galactic plane and should be classified to Sc galaxies,have been incorrectly classified to the earlier ones,because the tightness of spiral arms which is one of the criteria of the Hubble classification in RC3 is different between on the galactic plane and on the tangent plane of the celestial sphere.Our result also implies that there might exist biases in the luminosity functions of individual Hubble types if spiral galaxies are only classified visually.展开更多
基金Supported in part by the National Natural Sciences Foundation of China under Grant No.10073016,and NKBRSF G1999075406.
文摘A model considering gas outflows due to supernova explosions is developed for the star formation and chemical enrichment for the globular clusters (GCs) in the Milky Way galaxy. Through Monte Carlo simulations, the observed global properties of GCs can be well reproduced, including the metallicity distribution, no-correlation between cluster masses and galactocentric distances, etc. The predicted mass function of the parent clouds for the observed GCs at present day can be well described as a power law with the index of-1.8, which is consistent with the current observations for the molecular clouds.
基金Supported by both the National Natural Science Foundation of China under Grant 19603003,and K.C.Wong Education Foundation,Hong Kong。
文摘The normalized inclination distributions are presented for the spiral galaxies in RC3.The results show that,except for the bin of 81°-90°,in which the apparent minor isophotal diameters that are used to obtain the inclinations are affected by the central bulges,the distributions for Sa,Sab,Scd and Sd are well consistent with the Monte-Carlo simulation of random inclinations within 3-σ and Sb and Sbc almost,but Sc is different.One reason for the difference between the real distribution and the Monte-Carlo simulation of Sc may be that some quite inclined spirals,the arms of which are inherently loosely wound on the galactic plane and should be classified to Sc galaxies,have been incorrectly classified to the earlier ones,because the tightness of spiral arms which is one of the criteria of the Hubble classification in RC3 is different between on the galactic plane and on the tangent plane of the celestial sphere.Our result also implies that there might exist biases in the luminosity functions of individual Hubble types if spiral galaxies are only classified visually.
