在一个角度的花生：检测和测量的三维结构的酒吧在适度倾斜galvanic
Peanuts at an Angle: Detecting and Measuring the Three-Dimensional Structure of Bars in Moderately Inclined Galaxies
摘要：
我们表明，直接检测和测量的垂直加厚部分的酒吧（所谓的“四四方方”或“花生形”的凸起）是可能的，不仅对边缘的星系，但也为星系与中等倾角（i < 70度），和例子是比较常见的在附近的宇宙。对附近78个中等倾角（i < 65度）的早型（S 0-Sb）棒星系样本的分析表明，盒状/花生状星系的等光度线特征通常可以在倾角低至i ~ 40度时检测到，在特殊情况下可以低至i ~ 30度。与N体模拟的预测一致，当棒的位置角在星系长轴的50度以内时，签名最容易被检测到;特别是，棒非常接近短轴的星系不会清楚地显示签名或根本没有。对于i = 40- 65度和相对角< 45度的星系，我们发现了约2/3时间的签名的证据;棒中的盒子/花生结构的真实频率可能更高。与N体模型的比较也使我们能够将观察到的光度形态与3D物理结构联系起来，从而估计盒子/花生结构和酒吧的相对大小。对于我们的本地样本，我们发现盒/花生结构的径向尺寸范围（沿棒长轴测量）为0.4- 3.8 kpc（平均值= 1.5 +/- 0.9 kpc），跨度为棒长的0.26- 0.58（平均值为0.38 +/- 0.08）。这是一个清晰的观察证实，当酒吧，这不是整个酒吧这样做，而只是内部的一部分。这种技术也可以用来识别没有垂直加厚的酒吧星系。我们认为，NGC 3049和IC 676可能是特别好的例子，并且缺少盒/花生结构的S 0-Sb棒的分数至少为~ 13%。
英文摘要：
We show that direct detection and measurement of the vertically thickened parts of bars (so-called "boxy" or "peanut-shaped" bulges) is possible not only for edge-on galaxies but also for galaxies with moderate inclinations (i < 70 deg), and that examples are relatively common in the nearby universe. Analysis of a sample of 78 nearby, moderately inclined (i < 65 deg) early-type (S0--Sb) barred galaxies shows that the isophotal signature of the box/peanut can usually be detected for inclinations as low as i ~ 40 deg -- and in exceptional cases down to i ~ 30 deg. In agreement with the predictions from N-body simulations, the signature is most easily detectable when the bar's position angle is within ~ 50 deg of the galaxy major axis; in particular, galaxies where the bar lies very close to the minor axis do not show the signature clearly or at all. For galaxies with i = 40--65 deg and relative angles < 45 deg, we find evidence for the signature ~ 2/3 of the time; the true frequency of box/peanut structures in bars may be higher. Comparison with N-body models also allows us to link observed photometric morphology with 3D physical structures, and thus estimate the relative sizes of box/peanut structures and bars. For our local sample, we find that box/peanut structures range in radial size (measured along the bar major axis) from 0.4--3.8 kpc (mean = 1.5 +/- 0.9 kpc) and span 0.26--0.58 of the bar length (mean of 0.38 +/- 0.08). This is a clear observational confirmation that when bars thicken, it is not the entire bar which does so, but only the inner part. This technique can also be used to identify galaxies with bars which have not vertically thickened. We suggest that NGC 3049 and IC 676 may be particularly good examples, and that the fraction of S0--Sb bars which lack box/peanut structures is at least ~ 13%.
机构、总结、中文摘要均由AI分析而来，可能存在错误，请以论文正文为准。
