Serendipitous discovery of warm absorbers in the Seyfert 2 galaxy IRAS 18325-5926  

作　　者：Shui-Nai Zhang Qiu-Sheng Gu Li Ji Zhi-Xin Peng 

机构地区：[1]Department of Astronomy, Nanjing University, Nanjing 210093, China [2]Key Laboratory of Modern Astronomy and Astrophysics, Nanjing University, Ministry ofEducation, Nanjing 210093, China [3]Key Laboratory of Dark Matter and Space Astronomy, Purple Mountain Observatory, ChineseAcademy of Sciences, Nanjing 210008, China

出　　处：《Research in Astronomy and Astrophysics》2011年第10期1171-1184,共14页天文和天体物理学研究（英文版）

基　　金：provided by the Program for New Century Excellent Talents in University (NCET);the National Natural Science Foundation of China (Grant Nos. 10878010, 10221001 and 10633040);the National Basic Research Program of China (GrantNo. 2007CB815405)

摘　　要：Warm absorption is a common phenomenon in Seyfert 1 s and quasars, but is rare in Seyfert 2s. We report the detection of warm absorbers with high energy resolution in the Seyfert 2 galaxy IRAS 18325-5926 for the first time with Chandra HETGS spectra. An intrinsic absorbing line system with an outflow velocity - 400 km s^-1 was found, which is contributed by two warm absorbers with FWHM of 570 km s^-1 and 1360 km s^-1, respectively. The two absorbers were adjacent, and moving transversely across our line of sight. We constrained the distance between the center and the absorbers to be a small value, suggesting that the absorbers may originate from the highly ionized accretion disk wind ejected five years ago. The perspective of this type 2 Seyfert provides the best situation in which to investigate the vertical part of the funnel-like outflows. Another weak absorbing line system with zero redshift was also detected, which could be due to Galactic absorption with very high temperature or an intrinsic outflow with a very high velocity - 6000 km s^-1.Warm absorption is a common phenomenon in Seyfert 1 s and quasars, but is rare in Seyfert 2s. We report the detection of warm absorbers with high energy resolution in the Seyfert 2 galaxy IRAS 18325-5926 for the first time with Chandra HETGS spectra. An intrinsic absorbing line system with an outflow velocity - 400 km s^-1 was found, which is contributed by two warm absorbers with FWHM of 570 km s^-1 and 1360 km s^-1, respectively. The two absorbers were adjacent, and moving transversely across our line of sight. We constrained the distance between the center and the absorbers to be a small value, suggesting that the absorbers may originate from the highly ionized accretion disk wind ejected five years ago. The perspective of this type 2 Seyfert provides the best situation in which to investigate the vertical part of the funnel-like outflows. Another weak absorbing line system with zero redshift was also detected, which could be due to Galactic absorption with very high temperature or an intrinsic outflow with a very high velocity - 6000 km s^-1.

关 键 词：GALAXIES Seyfert -- galaxies absorption lines -- X-rays galaxies -- galaxies INDIVIDUAL IRAS 18325-5926 

分 类 号：P157.7[天文地球—天文学] P111.2