高能天体物理研究组知识库

用一个完备的带环星系样本以及它们的J,H,Ks三个波段的2MASS数据,采用考虑了多项因素的线性模型,研究带内环、外环以及伪内环这三类带环星系的共振环物理直径(D)与星系有效半径(R_e)之间的统计关系。其结果为:在带内环星系中,R_eαD~(0.76±0.07);在带外环星系中,R_eαD~(0.60±0.08);在伪内环星系中有R_eαD~(0.75±0.08)。将其与Wu在2008年得到的带环星系的星系近红外总光度(L_(NIR))与D的统计关系(L_(NIR)αD~(1.2))结合,得到带环星系L_(NIR)与R_e的系统关系,即L_(NIR)αR_e~β,对带内环、外环和伪内环的星系,β分别为1.58±0.15、2.00±0.27和1.60±0.17。这些推论和我们的直接测量结果大致相符。考虑到星系R_e与星系盘尺度(h_d)之间接近线性关系,以上结果较直接地检验了Wu在2008年得到的关于h_d与D的相关性结果,这也说明典型的带环星系的盘成分在总的动力学质量中的比例分布和盘早期温度仅有较小的系统变化。与其它关于星系的光度和尺度的经验统计关系相结合,这些结果提示带环星系的红外光度与盘尺度有与一般星系中的盘相近的统计关系。

Based on statistically complete samples of resonance-ringed galaxies compiled by Wu, and their 2MASS J, H, and Ks band data, we use liner models to fit the statistical correlations between their effective radii (Re) and physical ring diameters (D). In these models we have properly taken into account influences of various relevant factors. We find that galaxies with inner rings, outer rings, and inner pseudo rings have systematic relations Re ∝ D~(0:76±0:07), Re ∝ D~(0:60±0:08), and Re ∝ D~(0:75±0:08), respectively. Based on a correlation between galaxy total near-infrared luminosities (LNIR) and D found byWu, LNIR ∝ D~(1:2), we convert our results to correlations between LNIR and Re in ringed galaxies, LNIR ∝ R_e~β Forgalaxies with inner rings, outer ringers, and inner pseudo rings, β are 1.58±0:15, 2.00±0:27, and 1.60±0:17, respectively. These inferred values are roughly consistent with our direct measurements. Given the empirical liner correction between Re and galaxy disk scale lengths (hd), this relation confirms the suggested correlation between D and hd of Wu. It means that, among typical ringed galaxies of different disk temperature, there is not much variation in the fraction of disk to total dynamical mass. Combined with the empirical correlations between luminosities and hd, these results suggest that for disks in ringed galaxies, the correlations between Ld_(NIR)~d and h_d are close to those within general disk-galaxies.