Near-IR photometry of disk galaxies: Search for nuclear isophotal twist and double bars
Near-IR photometry of disk galaxies: Search for nuclear isophotal twist and double bars
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盘状星系的近红外光度测量：寻找核等光扭曲和双棒
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发表时间：
1997
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通讯作者：
Usa
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作者：
B. Jungwiert;F. Combes;D. J. A. Demirm;O. Paris;France.;Astron. Inst.;Prague;Czech republic Esa secondment;Stsi Baltimore;Usa
我们给出了72个邻近(MPC)盘星系的近红外光度测量，主要是H波段。这项调查的主要目标是在它们的核区内寻找等光速扭曲。由于扭曲在某些情况下可能是由于投影效应，而不是由动力学现象造成的，因此在2D几何的简化假设下，我们对所有其盘位置角和倾角已知的星系进行反投影，后者不超过。我们给出了椭圆度、位置角和表面亮度的径向分布，并讨论了2D和3D条形的投影如何扭曲等值线，给人一种不存在的双条形的错觉或掩盖真实的双条形。我们报告了15个新的双栏星系，并确认了之前探测到的2个。我们发现了14个以前未知的扭曲，我们还在三个SA星系中发现了核三轴结构。在有核棒或扭曲的星系中，塞弗特现象的频率很高。由于这些观测是一项更大的调查的一部分，一旦天体的数量增长到足以进行有意义的统计，对结果的解释将在未来的一篇论文中给出。作为二次产品，我们发布了大型棒材的结构参数(长度和轴比)，以扩展仍然稀缺的近红外棒材数据。
We present a near-IR, mainly H band, photometry of 72 nearby ( Mpc) disk galaxies. The main goal of the survey was to search for isophotal twist inside their nuclear regions. As the twist can be due in some cases to projection effects, rather than resulting from a dynamical phenomenon, we deproject – under the simplifying assumption of a 2D geometry – all galaxies whose disk position angle and inclination are known, the latter not exceeding . We show the ellipticity, position angle and surface brightness radial profiles, and discuss how a projection of 2D and 3D bars can distort the isophotes, give an illusion of a non-existing double bar or mask a real one. We report 15 new double-barred galaxies and confirm 2 detected previously. We identify 14 additional twists not known before and we also find nuclear triaxial structures in three SA galaxies. The frequency of Seyferts among galaxies with nuclear bars or twists is high. Since these observations are part of a larger survey, the interpretation of the results will be given in a future paper, as soon as the number of objects grows enough to permit meaningful statistics. As a secondary product, we publish structural parameters (length and axis ratio) of large-scale bars in order to extend still scarce data on bars in the near-IR.