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arXiv 1102.2736astro-ph.CO
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NGC 4486 A的动力学和恒星星族

Kinematics and stellar population of NGC 4486A

Philippe Prugniel, Werner Zeilinger, Mina Koleva, Sven de Rijcke

摘要:

NGC 4486 A是一个低光度的椭圆星系,拥有一个由恒星和尘埃组成的边缘核盘。它是一个超大质量黑洞的宿主。我们研究了它的大尺度运动学和长轴方向上的恒星星族分布,以探讨其核性质与整体性质之间的联系。我们使用长缝中等分辨率的光谱,我们适合对恒星星族模型。整个星系的SSP等效年龄约为12 Gyr,其金属丰度从中心附近的[Fe/H] = 0.18下降到外围的亚太阳值。在有效等照度线范围内,金属丰度梯度为-0.24 dex/10倍半径。在距中心1.3角秒处速度色散为132+-3公里/秒,并向外减小。在半径1.3 < r_max < 2 arcsec时,自转速度达到最大值V_max >~ 115 ± 5 km/s。NGC 4486 A是一个典型的低光度椭圆星系。在恒星星族中,没有任何迹象表明可能是古代的吸积/合并事件产生了这个圆盘。

英文摘要:

NGC 4486A is a low-luminosity elliptical galaxy harbouring an edge-on nuclear disk of stars and dust. It is known to host a super-massive black hole. We study its large-scale kinematics and stellar population along the major axis to investigate the link between the nuclear and global properties. We use long-slit medium-resolution optical spectra that we fit against stellar population models. The SSP-equivalent age is about 12 Gyr old throughout the body of the galaxy, and its metallicity decreases from [Fe/H] = 0.18 near the centre to sub-solar values in the outskirts. The metallicity gradient is -0.24 dex per decade of radius within the effective isophote. The velocity dispersion is 132+-3 km/s at 1.3 arcsec from the centre and decreases outwards. The rotation velocity reaches a maximum V_max >~ 115+-5 km/s at a radius 1.3 < r_max < 2 arcsec. NGC\,4486A appears to be a typical low-luminosity elliptical galaxy. There is no signature in the stellar population of the possible ancient accretion/merging event that produced the disk.

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。

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