ASCA Observation of the Low-Luminosity Seyfert 1.5 Galaxy NGC 5033
Author(s) -
Yuichi Terashima,
Hideyo Kunieda,
Kazutami Misaki
Publication year - 1999
Publication title -
publications of the astronomical society of japan
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.99
H-Index - 110
eISSN - 2053-051X
pISSN - 0004-6264
DOI - 10.1093/pasj/51.3.277
Subject(s) - physics , astrophysics , equivalent width , torus , galaxy , luminosity , active galactic nucleus , line (geometry) , astronomy , accretion disc , light curve , accretion (finance) , amplitude , emission spectrum , redshift , spectral line , optics , geometry , mathematics
We present the results of an ASCA observation of the low-luminosity Seyfert 1.5 galaxy NGC 5033. A point-like X-ray source with a luminosity of 2.3x10^{41} erg s^{-1} in the 2--10 keV band (at 18.7 Mpc; Tully 1988, AAA045.002.054) was detected at the nucleus. The X-ray light curve shows variability on a timescale of ~10^4 s with an amplitude of ~20%. The X-ray continuum is represented by a weakly absorbed (N_H~9x10^{20} {cm^{-2}) power-law with a photon index of 1.72+/-0.04, which is quite similar to Seyfert 1 galaxies with higher luminosities. A Fe Kalpha emission line is detected at 6.40^{+0.08}_{-0.06} keV (redshift corrected) and the equivalent width is 290+/-100 eV. The line width is unresolved. The narrower line width and larger equivalent width compared to Seyfert 1s imply that fluorescent Fe Kalpha emission from matter further out from the center than the accretion disk significantly contributes to the observed Fe Kalpha line. We suggest that fluorescent Fe Kalpha emission from the putative torus contributes to the observed Fe Kalpha line
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