2 research outputs found
OI Line Emission in the Quasar PG 1116+215
By observing the near-infrared spectrum of the quasar PG 1116+215 at z =
0.176 and combining with the HST/FOS spectrum, we obtained the relative
strengths of three permitted OI lines ({lambda}1304, {lambda}8446, and
{lambda}11287) in a quasar for the first time. The photon flux ratios of the OI
lines of the quasar were compared with those previously measured in a Seyfert 1
and six narrow-line Seyfert 1s. No significant differences were found in the OI
line flux ratios between the quasar and the other Seyferts, suggesting that the
gas density in the OI and FeII line-emitting regions in the quasar is of the
same order as those in low-luminosity AGNs. It was also found that the line
width of OI {lambda}11287 is significantly narrower than that of Ly{alpha},
which is consistent with OI and FeII emission occurring in the partly ionized
regions at the outermost portion of the broad-line region where velocities are
small.Comment: 6 pages, 2 figures, accepted by PASJ; minor wording changes
(01/07/2005
Fe II Emission in 14 Low-Redshift Quasars: I - Observations
We present the spectra of 14 quasars with a wide coverage of rest wavelengths
from 1000 to 7300 A. The redshift ranges from z = 0.061 to 0.555 and the
luminosity from M_{B} = -22.69 to -26.32. We describe the procedure of
generating the template spectrum of Fe II line emission from the spectrum of a
narrow-line Seyfert 1 galaxy I Zw 1 that covers two wavelength regions of
2200-3500 A and 4200-5600 A. Our template Fe II spectrum is semi-empirical in
the sense that the synthetic spectrum calculated with the CLOUDY
photoionization code is used to separate the Fe II emission from the Mg II
line. The procedure of measuring the strengths of Fe II emission lines is
twofold; (1) subtracting the continuum components by fitting models of the
power-law and Balmer continua in the continuum windows which are relatively
free from line emissions, and (2) fitting models of the Fe II emission based on
the Fe II template to the continuum-subtracted spectra. From 14 quasars, we
obtained the Fe II fluxes in five wavelength bands, the total flux of Balmer
continuum, and the fluxes of Mg II, Halpha, and other emission lines, together
with the full width at half maxima (FWHMs) of these lines. Regression analysis
was performed by assuming a linear relation between any two of these
quantities. Eight correlations were found with a confidence level higher than
99%. The fact that six of these eight are related to FWHM or M_{BH} may imply
that M_{BH} is a fundamental quantity that controls Gamma or the spectral
energy distribution (SED) of the incident continuum, which in turn controls the
Fe II emission. Furthermore, it is worthy of noting that Fe II(O1)/Fe II(U1) is
found to tightly correlate with Fe II(O1)/Mg II, but not with Fe II(U1)/Mg II.Comment: 50 pages, 10 figures, accepted for publication in Ap