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osu1028570377.pdf (2.96 MB)
ETD Abstract Container
Abstract Header
Multi-Wavelength Study of Narrow-Line Seyfert 1 Galaxies
Author Info
Romano, Patrizia
Permalink:
http://rave.ohiolink.edu/etdc/view?acc_num=osu1028570377
Abstract Details
Year and Degree
2002, Doctor of Philosophy, Ohio State University, Astronomy.
Abstract
We study the multiwavelength properties of Ark 564 and Ton S180, two NLS1s that have been the object of extensive multiwavelength spectroscopic campaigns undertaken during the last four years to test the current hypothesis that Narrow-Line Seyfert 1 galaxies (NLS1s) have relatively lower black hole masses and higher accretion rates than normal broad-line Seyfert 1 galaxies (BLS1s) of the same luminosity. We present an analysis of the X-ray variability properties of Ark 564 and Ton S180, based on 35- and 12-day continuous observations with ASCA, respectively. The mean spectra are characterized by a very steep power-law continuum (Gamma = 2.54 and 2.44, respectively), a strong soft excess at energies lower than 2 keV, and an Fe Kalpha line that has a large equivalent width and originates in ionized material. Their spectral energy distributions peak at significantly higher energies in these objects than in BLS1s (15-100 eV for Ton S180 and approximately 50 eV in Ark 564). We also find that, based on available UV, FUV and X-ray data on absorption lines, the UV and X-ray absorbers in Ark 564 are physically related, and possibly identical. The multiwavelength properties of these two NLS1s are consistent with the predictions of the prevailing model for the structure of NLS1s, i.e. of AGNs with high accretion rate (Mdot approximately 0.1-0.9) onto a relatively low-mass black hole (M approximately 1-10 million solar masses).
Committee
Bradley Peterson (Advisor)
Pages
242 p.
Subject Headings
Physics, Astronomy and Astrophysics
Keywords
Active Galactic Nuclei
;
Seyfert Galaxies
;
Narrow-Line Seyfert Galaxies
;
Arakelian 564
;
Ton S180
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Citations
Romano, P. (2002).
Multi-Wavelength Study of Narrow-Line Seyfert 1 Galaxies
[Doctoral dissertation, Ohio State University]. OhioLINK Electronic Theses and Dissertations Center. http://rave.ohiolink.edu/etdc/view?acc_num=osu1028570377
APA Style (7th edition)
Romano, Patrizia.
Multi-Wavelength Study of Narrow-Line Seyfert 1 Galaxies.
2002. Ohio State University, Doctoral dissertation.
OhioLINK Electronic Theses and Dissertations Center
, http://rave.ohiolink.edu/etdc/view?acc_num=osu1028570377.
MLA Style (8th edition)
Romano, Patrizia. "Multi-Wavelength Study of Narrow-Line Seyfert 1 Galaxies." Doctoral dissertation, Ohio State University, 2002. http://rave.ohiolink.edu/etdc/view?acc_num=osu1028570377
Chicago Manual of Style (17th edition)
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Document number:
osu1028570377
Download Count:
756
Copyright Info
© 2002, all rights reserved.
This open access ETD is published by The Ohio State University and OhioLINK.