Related papers: The FeII Optical Emission in AGN
We study the low-contrast Fe II emission blends in the ultraviolet (1250--2200A) and optical (4000--6000A) spectra of the Seyfert 1 galaxy NGC 5548 and show that these features vary in flux and that these variations are correlated with…
We present the optical spectra and simple statistical analysis for a complete sample of 110 soft X-ray selected AGN. About half of the sources are Narrow-Line Seyfert 1 galaxies (NLS1s), which have the steepest X-ray spectra, strongest FeII…
We present theoretical FeII emission line strengths for physical conditions typical of Active Galactic Nuclei with Broad-Line Regions. The FeII line strengths were computed with a precise treatment of radiative transfer using extensive and…
The issue of the difference between optical and UV properties of radio-quiet and radio-loud (relativistically "jetted") active galactic nuclei (AGN) is a long standing one, related to the fundamental question of why a minority of powerful…
This is the third in a series of papers reporting on a large reverberation-mapping campaign aimed to study the properties of active galactic nuclei (AGNs) with high accretion rates. We present new results on the variability of the optical…
The variability of optical FeII blends in NGC 4051 is examined from spectra extracted from the AGN Watch program.In our analysis, the FeII complex are subtracted and measured with the following results. Firstly, the FeII variations were…
We present an empirical template spectrum suitable for fitting/subtracting and studying the FeII and FeIII line emission in the restframe UV spectra of active galatic nuclei (AGNs), the first empirical UV iron template to cover the full…
Constraining the physical conditions of the ionized media in the vicinity of an active supermassive black hole (SMBH) is crucial to understanding how these complex systems operate. Metal emission lines such as iron (Fe) are useful probes to…
Direct correlations and a Principal Component Analysis (PCA) are presented for a complete sample of 110 soft X-ray selected AGN of which about half are Narrow-Line Seyfert 1 galaxies (NLS1s). The direct correlation analyses show that…
We present near-infrared spectra with resolutions of lambda/dlambda~1200 in the emission lines of Pa-beta, [FeII] (1.2567um), Br-gamma, and H2 v=1-0S(1) of the nuclei and circumnuclear regions of the four Seyfert 2 galaxies Mk 1066, NGC…
We report on a spectroscopic confirmation of narrowband-selected [OII] emitters in Abell 851 catalogued by Martin et al. (2000). The optical spectra obtained from the Keck I Low Resolution Imaging Spectrometer (LRIS) and Keck II Deep…
We investigate the relationship between H\alpha\ and [OII](\lambda 3727) emission in faint star-forming galaxies at z=1.47 with dust uncorrected star formation rates (SFRs) down to 1.4 Msun/yr, using data in two narrow-bands from…
We present a reverberation analysis of the strong, variable optical Fe II emission bands in the spectrum of Akn 120, a low-redshift AGN which is one of the best candidates for such a study. On time scales of several years the Fe II line…
We present results of the near-infrared (IR) spectroscopy of six quasars whose redshifts range from 0.158 to 1.084. Combined with the satellite ultraviolet data, the relative line strengths of OI 1304, OI 8446, OI 11287, and the near-IR…
The 6.4 keV Fe Ka emission line is a ubiquitous feature in X-ray spectra of AGN, and its properties track the interaction between the variable primary X-ray continuum and the surrounding structure from which it arises. We clarify the nature…
We used a very large set of models of broad emission line (BEL) clouds in AGN to investigate the formation of the observed Fe II emission lines. We show that photoionized BEL clouds cannot produce both the observed shape and observed…
One of the puzzles in understanding the spectra of active galactic nuclei (AGN) is the origin of the FeII emission. FeI emission, if present, will help reveal the physical conditions of the emitting gas. In an attempt to verify the presence…
We present a study of the prevalence, strength, and kinematics of ultraviolet FeII and MgII emission lines in 212 star-forming galaxies at z = 1 selected from the DEEP2 survey. We find FeII* emission in composite spectra assembled on the…
Here we present a critical view of practical problems in the analysis of optical Fe II emission lines of Type 1 AGN spectra. Besides the very complex and unclear physical interpretation of the Fe II template shape, there are other issues…
From detailed spectral analysis of a large sample of low-redshift active galactic nuclei (AGNs) selected from the Sloan Digital Sky Survey, we demonstrate---statistically for the first time---that narrow optical Fe II emission lines, both…