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Related papers: What controls the Fe II strength in active galacti…

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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…

We review problems raised by Fe II emission in AGNs and address the question of its relationship to other broad-line region (BLR) lines. The self-shielding, stratified, BLR model of Gaskell, Klimek & Nazarova (2007; GKN) predicts that Fe II…

Astrophysics of Galaxies · Physics 2022-02-16 C. Martin Gaskell , Neha Thakur , Betsy Tian , Anjana Saravana

We revisit the correlation between the mid-infrared (6 $\mu$m) and hard X-ray (2--10 keV) luminosities of active galactic nuclei (AGNs) to understand the physics behind it. We construct an X-ray flux-limited sample of 571 type 1 AGNs with…

We investigate FeII emission in Broad Line Region (BLR) of AGNs by analyzing the FeII(UV), FeII(4570) and MgII emission lines in 884 quasars in the Sloan Digital Sky Survey (SDSS) Quasar catalog in a redshift range of 0.727 < z < 0.804.…

Astrophysics of Galaxies · Physics 2015-05-19 H. Sameshima , K. Kawara , Y. Matsuoka , S. Oyabu , N. Asami , N. Ienaka

The CaFe Project involves the study of the properties of the low ionization emission lines (LILs) pertaining to the broad-line region (BLR) in active galaxies. These emission lines, especially the singly-ionized iron (Fe II) in the optical…

Astrophysics of Galaxies · Physics 2021-11-30 Swayamtrupta Panda

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…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-15 K. A. Kornei , A. E. Shapley , C. L. Martin , A. L. Coil , J. M. Lotz , B. J. Weiner

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…

Astrophysics · Physics 2009-11-10 D. Grupe

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…

Astrophysics of Galaxies · Physics 2015-05-27 Chen Hu , Pu Du , Kai-Xing Lu , Yan-Rong Li , Fang Wang , Jie Qiu , Jin-Ming Bai , Shai Kaspi , Luis C. Ho , Hagai Netzer , Jian-Min Wang

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…

Astrophysics · Physics 2009-11-07 T. A. A. Sigut , Anil K. Pradhan

Both the Fe II UV emission in the 2000- 3000 A region [Fe II (UV)] and resonance emission line complex of Mg II at 2800 A are prominent features in quasar spectra. The observed Fe II UV/ Mg II emission ratios have been proposed as means to…

Astrophysics · Physics 2009-11-10 E. Verner , F. Bruhweiler , D. Verner , S. Johansson , T. Gull

We obtained 0.8-2.4 micron spectra at a resolution of 320 km/s of four narrow-line Seyfert 1 galaxies in order to study the near-infrared properties of these objects. We focus on the analysis of the FeII emission in that region and the…

Astrophysics · Physics 2009-11-07 A. Rodriguez-Ardila , S. M. Viegas , M. G. Pastoriza , L. Prato

We study the kinematics and excitation mechanisms of H2 and [Fe II] lines in a sample of 67 emission-line galaxies with Infrared Telescope Facility SpeX near-infrared (NIR, 0.8-2.4 micrometers) spectroscopy together with new photoionisation…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-12 R. Riffel , A. Rodriguez-Ardila , I. Aleman , M. S. Brotherton , M. G. Pastoriza , C. J. Bonatto , O. L. Dors

We present results from analysis of spectra from a sample of ~900 quasars from the Sloan Digital Sky Survey. These objects were selected for their intermediate redshift (1.2<z<1.8), placing MgII and UV FeII in the optical band pass,…

Astrophysics · Physics 2009-11-10 Karen M. Leighly , John R. Moore

We present the kinematical properties of the UV and optical \FeII\ emission gas based on the velocity shift and line width measurements of a sample of 223 Type 1 active galactic nuclei (AGNs) at 0.4 $<$ z $<$ 0.8. We find a strong…

Astrophysics of Galaxies · Physics 2020-01-08 Huynh Anh N. Le , Jong-Hak Woo

We measure the Eddington ratio distribution of local optical narrow-line active galactic nuclei (AGN) as a function of host galaxy properties, as a potential test of galaxy formation theories of AGN feedback. We extract central…

Astrophysics of Galaxies · Physics 2026-05-11 Michael R. Blanton , Arjun Suresh , Kyle B. Westfall , Dou Liu , John Moustakas

We investigate the effect of Fe II equivalent width ($W_{2600}$) and fibre size on the average luminosity of [O II]$\lambda\lambda$3727,3729 nebular emission associated with Mg II absorbers (at $0.55 \le z \le 1.3$) in the composite spectra…

Astrophysics of Galaxies · Physics 2018-01-31 Ravi Joshi , Raghunathan Srianand , Patrick Petitjean , Pasquier Noterdaeme

In an effort to better calibrate the supernova rate of starburst galaxies as determined from near-IR [Fe II] features, we report on a [Fe II] 1.644 microns line-imaging survey of a sample of 42 optically-selected SNRs in M33. A wide range…

Astrophysics · Physics 2009-11-07 T. Morel , R. Doyon , N. St-Louis

We have calculated FeII emission line strengths for Active Galactic Nuclei Broad-Line Regions using precise radiative transfer and Iron Project atomic data. We improve the treatment of all previously considered excitation mechanisms for the…

Astrophysics · Physics 2009-10-30 T. A. A. Sigut , Anil K. Pradhan

We revisited the spectroscopic characteristics of narrow-line Seyfert 1 galaxies (NLS1s) by analysing a homogeneous sample of 296 NLS1s at redshift between 0.028 and 0.345, extracted from the Sloan Digital Sky Survey (SDSS-DR7) public…

Astrophysics of Galaxies · Physics 2016-08-17 V. Cracco , S. Ciroi , M. Berton , F. Di Mille , L. Foschini , G. La Mura , P. Rafanelli

We present a semi-empirical calibration between the metallicity ($Z$) of Seyfert 2 Active Galactic Nuclei and the $N2$=log([N II]$\lambda$6584/H$\alpha$) emission-line intensity ratio. This calibration was derived through the [O…