标题： HST/ACS 低红移 3CR 射电星系的发射线成像 第一章：数据 显示英文标题

标题： HST/ACS Emission Line Imaging of Low Redshift 3CR Radio Galaxies I: The Data

摘要： 我们展示了19个附近的（z<0.3）3CR射电星系，这些星系在低激发和高激发状态下成像，作为一项周期15哈勃空间望远镜快照调查的一部分，使用了先进巡天相机。 这些图像包括对 H-alpha（6563 \AA ，加上[NII]污染）和[OIII]5007 \AA 发射线的曝光，使用根据目标红移调整的窄带线性斜坡滤光片。 为了便于连续谱减除，使用适合目标红移的中等带宽滤光片进行了一次单点60秒无线曝光。 我们讨论了为独立于自动重新校准流程而采取的图像处理步骤，以便使用更近期的ACS平场数据以及更好地排除宇宙射线。 我们描述了生成无连续谱（纯发射线）图像的方法，并呈现这些图像以及我们观察到的窄线区形态的定性描述。 我们提供了通过孔径测光得到的H-alpha+[NII]和[OIII]线流量，发现这些值如预期地落在过去HST/WFPC2发射线研究中较大且通常红移较高的3CR子集的红移-光度趋势上。 我们还发现了发射线光度与总射电功率之间的预期趋势，以及发射线区大小与红移之间的正相关关系。 我们讨论了这些结果的相关解释，并以本数据集所启用的未来工作的总结结束。 显示英文摘要

摘要： We present 19 nearby (z<0.3) 3CR radio galaxies imaged at low- and high-excitation as part of a Cycle 15 Hubble Space Telescope snapshot survey with the Advanced Camera for Surveys. These images consist of exposures of the H-alpha (6563 \AA, plus [NII] contamination) and [OIII] 5007 \AA emission lines using narrow-band linear ramp filters adjusted according to the redshift of the target. To facilitate continuum subtraction, a single-pointing 60 s line-free exposure was taken with a medium-band filter appropriate for the target's redshift. We discuss the steps taken to reduce these images independently of the automated recalibration pipeline so as to use more recent ACS flat-field data as well as to better reject cosmic rays. We describe the method used to produce continuum-free (pure line-emission) images, and present these images along with qualitative descriptions of the narrow-line region morphologies we observe. We present H-alpha+[NII] and [OIII] line fluxes from aperture photometry, finding the values to fall expectedly on the redshift-luminosity trend from a past HST/WFPC2 emission line study of a larger, generally higher redshift subset of the 3CR. We also find expected trends between emission line luminosity and total radio power, as well as a positive correlation between the size of the emission line region and redshift. We discuss the associated interpretation of these results, and conclude with a summary of future work enabled by this dataset.