Fe–K LINE TIME VARIABILITY AND Ni ABUNDANCE OF DISTANT REFLECTORS IN SEYFERT GALAXIES

Journal Article · Sun Apr 10 04:00:00 EDT 2016 · Astrophysical Journal

DOI:https://doi.org/10.3847/0004-637X/821/1/15· OSTI ID:22518512

Fukazawa, Yasushi; Furui, Shun’ya; Hayashi, Kazuma; Ohno, Masanori; Hiragi, Kazuyoshi ^[1]; Noda, Hirofumi ^[2]

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1. Department of Physical Science, Hiroshima University, 1-3-1 Kagamiyama, Higashi-Hiroshima, Hiroshima 739-8526 (Japan)
2. Nishina Center, Institute of Physical and Chemical Research (RIKEN), Wako, Saitama 351-0198 (Japan)

We have performed systematic studies of narrow Fe–K line (6.4 keV) flux variability and Ni–K line intensity for Seyfert galaxies, using Suzaku and XMM-Newton archival data. Significant Fe–K line variability of several tens of percent was detected for a pair of observations separated by 1000–2000 days (Cen A, IC 4329 A, NGC 3516, and NGC 4151) and 158 days (NGC 3516). These timescales are larger by a factor of 10–100 than the inner radius of the torus, consistent with the view that X-ray reflection by a torus is a main origin for a narrow Fe–K line. The Ni–K line was detected with a >2σ level for the Circinus galaxy, Cen A, MRK 3, NGC 4388, and NGC 4151. A mean and variance of the Ni–Kα to Fe–Kα line intensity ratios are 0.066 and 0.026, respectively. Comparing this with the Monte-Carlo simulation of reflection, the Ni to Fe abundance ratio is 1.9 ± 0.8 solar. We discuss the results and the possibility of Ni abundance enhancement.

• OSTI ID: 22518512
• Journal Information: Astrophysical Journal, Journal Name: Astrophysical Journal Journal Issue: 1 Vol. 821; ISSN ASJOAB; ISSN 0004-637X
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTRONOMY AND ASTROPHYSICS
COMPARATIVE EVALUATIONS
COMPUTERIZED SIMULATION
ELEMENT ABUNDANCE
IRON
KEV RANGE
MONTE CARLO METHOD
NICKEL
POTASSIUM
REFLECTION
SEYFERT GALAXIES
STAR CLUSTERS
X-RAY GALAXIES