論文

基本情報

氏名 渡邉 誠
氏名(カナ) ワタナベ マコト
氏名(英語) Watanabe Makoto
所属 理学部 物理学科
職名 准教授
researchmap研究者コード B000222325
researchmap機関 岡山理科大学

題名

Narrow Fe–Kα Reverberation Mapping Unveils the Deactivated Broad-line Region in a Changing-look Active Galactic Nucleus

単著・共著の別

共著

著者

Hirofumi Noda, Taisei Mineta,Takeo Minezaki, Hiroaki Sameshima, Mitsuru Kokubo, Taiki Kawamuro, Satoshi Yamada, Takashi Horiuchi, Hironori Matsumoto, Makoto Watanabe, Kumiko Morihana, Yoichi Itoh, Koji S. Kawabata, Yasushi Fukazawa

概要

"Changing-look active galactic nuclei" (CLAGNs) are known to change their apparent types between types 1 and 2, usually accompanied by a drastic change in their luminosity on timescales of years. However, it is still unclear whether materials in broad-line regions (BLRs) in CLAGNs appear and disappear during the type-transition or remain at the same location while the line production is simply activated or deactivated. Here we present our X-ray-optical monitoring results of a CLAGN, NGC 3516, by Suzaku, Swift, and ground telescopes, with our primary focus on the narrow Fe-Kα emission line, which is an effective probe of the BLR materials. We detected significant variations of the narrow Fe-Kα line on a timescale of tens of days during the type-2 (faint) phase in 2013-2014, and conducted "narrow Fe-Kα reverberation mapping," comparing its flux variation with those of the X-ray continuum from a corona and B-band continuum from an accretion disk. We derived, as a result, a time lag of 10.1+5.8−5.6 days (1σ errors) for the Fe-Kα line behind the continuum, which is consistent with the location of the BLR determined in optical spectroscopic reverberation mapping during the type-1 (bright) phase. This finding shows that the BLR materials remained at the same location without emitting optical broad lines during the type-2 phase. Considering the drastic decrease of the radiation during the type-transition, our result is possibly inconsistent with the hotly discussed formation models of the BLR, which propose that the radiative pressure from an accretion disk should be the main driving force.

発表雑誌等の名称

The Astrophysical Journal

出版者

American Astronomical Society

943

1

開始ページ

63

終了ページ

発行又は発表の年月

2023/01

査読の有無

有り

招待の有無

無し

記述言語

英語

掲載種別

研究論文(学術雑誌)

ISSN

0004-637X

ID:DOI

10.3847/1538-4357/aca963

ID:NAID(CiNiiのID)

ID:PMID

URL

JGlobalID

arXiv ID

ORCIDのPut Code

DBLP ID