Ultraviolet Fe II emission in z ~ 2 quasars
arXiv:0902.2057 · doi:10.1111/j.1365-2966.2009.14605.x
Abstract
We present spectra of six luminous quasars at z ~ 2, covering rest wavelengths 1600-3200 A. The fluxes of the UV Fe II emission lines and Mg II 2798 doublet, the line widths of Mg II, and the 3000 A luminosity were obtained from the spectra. These quantities were compared with those of low-redshift quasars at z = 0.06 - 0.55 studied by Tsuzuki et al. In a plot of the Fe II(UV)/Mg II flux ratio as a function of the cental black hole mass, Fe II(UV)/Mg II in our z ~ 2 quasars is systematically greater than in the low-redshift quasars. We confermed that luminosity is not responsible for this excess. It is unclear whether this excess is caused by rich Fe abundance at z ~ 2 over low-redshift or by non-abundance effects such as high gas density, strong radiation field, and high microturbulent velocity.
5pages, 5figures, 2tables, accepted for publication in MNRAS
References in corpus (17)
- Maps of Dust IR Emission for Use in Estimation of Reddening and CMBR Foregrounds
- A Physical Model for the Co-evolution of QSOs and of their Spheroidal Hosts
- Measuring the black hole masses of high redshift quasars
- On the typical timescale for the chemical enrichment from SNeIa in Galaxies
- Fe II Emission in 14 Low-Redshift Quasars: I - Observations
- Black hole masses and enrichment of z ~ 6 SDSS quasars
- The Origin of Fe II Emission in AGN
- FeII/MgII Emission Line Ratio in High Redshift Quasars
- Iron Emission in z~6 QSOs
- High Redshift Quasars and Star Formation in the Early Universe
- Early star formation traced by the highest redshift quasars
- Formation and evolution of elliptical galaxies and QSO activity
- FeII/MgII Emission Line Ratios of QSOs. II. z>6 Objects
- Observations of OI and CaII Emission Lines in Quasars: Implications for the Site of FeII Line Emission
- Age Dating of a High-Redshift QSO B1422+231 at Z=3.62 and its Cosmological Implications
- Revisited abundance diagnostics in quasars: Fe II/Mg II ratios
- Low-Ionization Emission Regions in Quasars: Gas Properties Probed with Broad O I and Ca II Lines
Cited by in corpus (9)
- Physical properties of 15 quasars at
- The Rest-Frame Submillimeter Spectrum of High-Redshift, Dusty, Star-Forming Galaxies
- Weak 13CO in the Cloverleaf Quasar: evidence for a young, early generation starburst
- Chemical evolution of the Universe at 0.7 < z < 1.6 derived from abundance diagnostics of the broad-line region of quasars
- Implications from the optical to UV flux ratio of FeII emission in quasars
- Mg II and Fe II fluxes of luminous quasars at z ~ 2.7 and evaluation of the Baldwin effect in the flux-to-abundance conversion method for quasars
- Evidence of Increased UV FeII Emission in Quasars in Candidate Overdense Regions
- Ultraviolet Fe II Emission in Fainter Quasars: Luminosity Dependences, and the Influence of Environments
- Early metal enrichment in high-redshift quasars