The UV spectra of NLS1s - implications for their broad line regions

J. K. Kuraszkiewicz; B. J. Wilkes; B. Czerny; S. Mathur; W. N. Brandt; M. Vestergaard

doi:10.1016/S1387-6473(00)00102-0

The UV spectra of NLS1s - implications for their broad line regions

J. K. Kuraszkiewicz^*, B. J. Wilkes, B. Czerny, S. Mathur, W. N. Brandt, M. Vestergaard

^*Corresponding author af dette arbejde

2 Citationer (Scopus)

Abstract

We study the UV spectra of NLS1 galaxies and compare them with typical Seyfert 1 galaxies and quasars. The NLS1 spectra show narrower UV lines as well as weaker CIVλ1549 and CIII]λ1909 emission. We show that these line properties are due to a lower ionization parameter and somewhat higher BLR cloud densities. These modified conditions can be explained by the hotter big blue bumps observed in NLS1s, which are in turn due to higher L/L_Edd ratios, as shown by our accretion disk and corona modeling of the NLS1 continua. We also present evidence that the Boroson and Green eigenvector 1, which is correlated with the optical and UV emission-line properties, is not driven by orientation and hence NLS1s, which have extreme eigenvector 1 values, are not viewed from an extreme viewing angle.

Originalsprog	Engelsk
Tidsskrift	New Astronomy Reviews
Vol/bind	44
Udgave nummer	7-9
Sider (fra-til)	573-575
Antal sider	3
ISSN	1387-6473
DOI	https://doi.org/10.1016/S1387-6473(00)00102-0
Status	Udgivet - sep. 2000
Udgivet eksternt	Ja

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title = "The UV spectra of NLS1s - implications for their broad line regions",

abstract = "We study the UV spectra of NLS1 galaxies and compare them with typical Seyfert 1 galaxies and quasars. The NLS1 spectra show narrower UV lines as well as weaker CIVλ1549 and CIII]λ1909 emission. We show that these line properties are due to a lower ionization parameter and somewhat higher BLR cloud densities. These modified conditions can be explained by the hotter big blue bumps observed in NLS1s, which are in turn due to higher L/LEdd ratios, as shown by our accretion disk and corona modeling of the NLS1 continua. We also present evidence that the Boroson and Green eigenvector 1, which is correlated with the optical and UV emission-line properties, is not driven by orientation and hence NLS1s, which have extreme eigenvector 1 values, are not viewed from an extreme viewing angle.",

keywords = "Galaxies: active, Quasars: emission lines",

author = "Kuraszkiewicz, {J. K.} and Wilkes, {B. J.} and B. Czerny and S. Mathur and Brandt, {W. N.} and M. Vestergaard",

year = "2000",

month = sep,

doi = "10.1016/S1387-6473(00)00102-0",

language = "English",

volume = "44",

pages = "573--575",

journal = "New Astronomy Reviews",

issn = "1387-6473",

publisher = "Elsevier BV * North-Holland",

number = "7-9",

}

TY - JOUR

T1 - The UV spectra of NLS1s - implications for their broad line regions

AU - Kuraszkiewicz, J. K.

AU - Wilkes, B. J.

AU - Czerny, B.

AU - Mathur, S.

AU - Brandt, W. N.

AU - Vestergaard, M.

PY - 2000/9

Y1 - 2000/9

N2 - We study the UV spectra of NLS1 galaxies and compare them with typical Seyfert 1 galaxies and quasars. The NLS1 spectra show narrower UV lines as well as weaker CIVλ1549 and CIII]λ1909 emission. We show that these line properties are due to a lower ionization parameter and somewhat higher BLR cloud densities. These modified conditions can be explained by the hotter big blue bumps observed in NLS1s, which are in turn due to higher L/LEdd ratios, as shown by our accretion disk and corona modeling of the NLS1 continua. We also present evidence that the Boroson and Green eigenvector 1, which is correlated with the optical and UV emission-line properties, is not driven by orientation and hence NLS1s, which have extreme eigenvector 1 values, are not viewed from an extreme viewing angle.

AB - We study the UV spectra of NLS1 galaxies and compare them with typical Seyfert 1 galaxies and quasars. The NLS1 spectra show narrower UV lines as well as weaker CIVλ1549 and CIII]λ1909 emission. We show that these line properties are due to a lower ionization parameter and somewhat higher BLR cloud densities. These modified conditions can be explained by the hotter big blue bumps observed in NLS1s, which are in turn due to higher L/LEdd ratios, as shown by our accretion disk and corona modeling of the NLS1 continua. We also present evidence that the Boroson and Green eigenvector 1, which is correlated with the optical and UV emission-line properties, is not driven by orientation and hence NLS1s, which have extreme eigenvector 1 values, are not viewed from an extreme viewing angle.

KW - Galaxies: active

KW - Quasars: emission lines

UR - http://www.scopus.com/inward/record.url?scp=0043207858&partnerID=8YFLogxK

U2 - 10.1016/S1387-6473(00)00102-0

DO - 10.1016/S1387-6473(00)00102-0

M3 - Review

AN - SCOPUS:0043207858

SN - 1387-6473

VL - 44

SP - 573

EP - 575

JO - New Astronomy Reviews

JF - New Astronomy Reviews

IS - 7-9

ER -

The UV spectra of NLS1s - implications for their broad line regions

Abstract

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