Related papers: Mg II line properties in lobe-dominated quasars

We present new Gemini/GMOS optical spectroscopy of 16 extreme variability quasars (EVQs) that dimmed by more than 1.5 mag in the $g$ band between the Sloan Digital Sky Survey (SDSS) and the Dark Energy Survey (DES) epochs (separated by a…

Line emission from an accretion disk and a corotating hot spot about a rotating black hole are considered for possible signatures of the frame-dragging effect. We explicitly compare integrated line profiles from a geometrically thin disk…

Mapping Mg II resonance emission scattered by galactic winds offers a means to determine the spatial extent and density of the warm outflow. Using Keck/LRIS spectroscopy, we have resolved scattered Mg II emission to the east of 32016857, a…

The nature of the galaxies that give rise to absorption lines, such as damped Lyman-alpha systems (DLAs) or strong MgII lines, in quasar spectra is difficult to investigate in emission. Taking advantage of the total absorption of the QSO…

Active galactic nuclei (AGN) have Fe II emission from the broad line region (BLR) that differs greatly in strength from object to object. We examine the role of the total and gas-phase iron abundance in determining Fe II strength. Using AGN…

We report near-infrared spectroscopic data for the Seyfert 2 galaxy Mrk 78, taken with the LIRIS near-infrared camera/spectrometer at the William Herschel Telescope (WHT). The long-slit spectra clearly show extended emission. The resolution…

(Abridged) We analyzed the {\it Chandra} and {\it XMM-Newton} archival observations for 72 type 2 quasars at $z<1$. These objects were was selected based on the [O III]$\lambda$5007 optical emission line which we assume to be an approximate…

The z=3.02 quasar SDSS J095253.83+011421.9 exhibits broad metal-line emission (CIV FWHM=9000 km/s), but broad Ly-alpha emission is not present. Instead, only a narrow Ly-alpha line is observed (FWHM=1140 km/s). The large CIV/Ly-alpha ratio…

The FeII/MgII line flux ratio has been used to investigate the chemical evolution of high redshift active galactic nuclei (AGNs). No strong evolution has been found out to z~6, implying that the type 1a supernova activity has been already…

As the 15th paper in a series reporting on a large reverberation mapping (RM) campaign of super-Eddington accreting massive black holes (SEAMBHs) in active galactic nuclei (AGNs), we present the results of measurements of the Mg II lines in…

We present the results of photoionization modeling of nine weak MgII (W_r<0.3 Ang) quasar absorption line systems with redshifts 1.4<z<2.4 obtained with the Ultraviolet and Visual Echelle Spectrograph on the Very Large Telescope. These…

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…

We highlight the importance of the MgII emission-line doublet in probing high-redshift quasars and their supermassive black holes. In the SDSS era, where large scale investigations of quasars across the age of the Universe are possible,…

We present the results of reanalysis of low z Mg II absorption line sample compiled by SS92. The conditions on cloud parameters to produce N(Fe II)>N(Mg II) are obtained using photoionization models and curve of growth. Properties of Mg II…

We present optical spectroscopy of projected QSO pairs to investigate the MgII and the CIV absorption features imprinted on the spectrum of the background object by the gaseous halo surrounding the foreground QSO. We observed 13 projected…

[Abridged] We examine a sample of 45 Mg II absorption-selected systems over the redshift range 0.4 to 1.4. Mg II and Fe II absorption profiles were observed at a resolution of ~6 km/s with HIRES/Keck. Lyman-alpha and C IV data were measured…

Strong foreground absorption features from singly-ionized Magnesium (Mg II) are commonly observed in the spectra of quasars and are presumed to probe a wide range of galactic environments. To date, measurements of the average dark matter…

New reverberation mapping measurements of the size of the optical iron emission-line region in quasars are provided, and a tentative size-luminosity relation for this component is reported. Combined with lag measurements in low-luminosity…

The enrichment of Fe, relative to alpha-elements such as O and Mg, represents a potential means to determine the age of quasars and probe the galaxy formation epoch. To explore how \ion{Fe}{2} emission in quasars is linked to physical…

Massive black hole binaries at sub-parsec separations may display in their spectra anomalously small flux ratios between the MgII and CIV broad emission lines, i.e. F_MgII/F_CIV <~ 0.1, due to the erosion of the broad line region around the…