名古屋大学U研X線グループ
名古屋大学大学院理学研究科 素粒子宇宙物理学専攻 宇宙物理学研究室
〒464-8602  名古屋市千種区不老町 Tel:052-789-2921 Fax:052-789-2919
 
Home Uir Site map English
ヘッダー
研究室紹介 研究プロジェクト 研究概要 研究成果 アクセスマップ お問い合わせ 関連リンク
研究成果
論文
論文リストEnglish
1990~1999
論文リストEnglish
2000~
論文リスト
博士論文リスト
修士論文リスト
新聞記事
 
publication

Detection of broad iron K lines in active galaxies

R.F. Mushotzky, A.C. Fabian, K. Iwasawa, H. Kunieda, M. Matsuoka, K. Nandra, Y. Tanaka

Abstract

X-ray spectra of Seyfert 1 galaxies obtains by the Ginga satellite showed the presence of a fluorescent iron line and a hard continuum tail, which are commonly interpreted as the signature of cold matter irradiated by the X-ray source. This matter could be in the form of either an accretion disc immediately around the central black hole or an outer torus at a radius of about a parsec. Here we use spectra of two such active galaxies taken with the ASCA satellite at higher spectral resolution to show, clearly, that the Fe lines are broad. Gaussian model fits show for IC4329A (z=0.016) that the line is centred at 6.19 keV in the observer's frame and has a FWHM of >20 000 km s^-1, and for NGC 5548 (z=0.017) that the line is at 6.15 keV with a FWHM of >35 000 km s^-1. The line centroids are shifted by >0.2 keV with respect to the expected rest-frame energy of a fluorescent line from cold material. The widths are considerably larger than the full widths of the optical or UV lines found in these objects of ~15 000 km s^-1. The intrinsic line profiles are not well determined, but are consistent with models of lines from the inner regions (<100 Schwarzschild radii) of accretion discs inclined at ~20 deg-30 deg. The discovery of such broad lines now opens up the immediate surroundings of accreting black holes for detailed study.

 
Copyright (c) 2008 Nagoya University . All Rights Reserved.  
 
トップページに戻る