Decomposition of the Host Galaxies of Active Galactic Nuclei Using Hubble Space Telescope Images
Decomposition of the Host Galaxies of Active Galactic Nuclei Using Hubble Space Telescope Images
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DOI：
10.1086/591796
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发表时间：
2008-07
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影响因子：
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通讯作者：
Minjin Kim;L. Ho;C. Peng;A. Barth;M. Im
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作者：
Minjin Kim;L. Ho;C. Peng;A. Barth;M. Im
研究超大质量黑洞和星系演化之间的联系需要仔细测量宿主星系的性质。我们进行模拟来测试的可靠性的二维图像拟合技术分解的宿主星系和活动星系核（AGN），特别是使用相机上的哈勃太空望远镜（HST），如宽视场行星相机2，先进的相机进行调查，近红外相机和多目标光谱仪获得的图像。我们量化的点扩散函数（PSF）的空间，时间和颜色变化的相对重要性。为了估计活动星系核到宿主分解的不确定性，我们进行了广泛的模拟，跨越了广泛的活动星系核到宿主星系的光度对比度，信噪比和宿主星系的属性（大小，光度，中心浓度）。我们发现，现实的PSF不匹配，通常困扰实际观测系统导致高估的主机星系的流量。部分问题是由于HST PSF采样不足造成的。我们证明，这个问题可以缓解扩大科学和PSF图像的关键采样，而不会丢失信息。对活动星系核宿主星系的HST图像的优化分析提出了一些实用的建议。
Investigating the link between supermassive black hole and galaxy evolution requires careful measurements of the properties of the host galaxies. We perform simulations to test the reliability of a two-dimensional image-fitting technique to decompose the host galaxy and the active galactic nucleus (AGN), especially on images obtained using cameras on board the Hubble Space Telescope (HST), such as the Wide-Field Planetary Camera 2, the Advanced Camera for Surveys, and the Near-Infrared Camera and Multi-Object Spectrometer. We quantify the relative importance of spatial, temporal, and color variations of the point-spread function (PSF). To estimate uncertainties in AGN-to-host decompositions, we perform extensive simulations that span a wide range in AGN-to-host galaxy luminosity contrast, signal-to-noise ratio, and host galaxy properties (size, luminosity, central concentration). We find that realistic PSF mismatches that typically afflict actual observations systematically lead to an overestimate of the flux of the host galaxy. Part of the problem is caused by the fact that the HST PSFs are undersampled. We demonstrate that this problem can be mitigated by broadening both the science and the PSF images to critical sampling without loss of information. Other practical suggestions are given for optimal analysis of HST images of AGN host galaxies.