The relationship between Mg II broad emission and quasar inclination angle
arXiv:1711.08926 · doi:10.3389/fspas.2017.00043
Abstract
Several observed spectral properties of quasars are believed to be influenced by quasar orientation. In this investigation we examine the effect of orientation on the Mg II line located at 2798 Å in a sample of 36 radio-loud quasars, with orientation angles having been obtained in a previous study using radio observations. We find no significant relationship between orientation angle and either Mg II line full-width at half-maximum or equivalent width. The lack of correlation with inclination angle contradicts previous studies which also use radio data as a proxy for inclination angle and suggests the Mg II emission region does not occupy a disk-like geometry. The lack of correlation with Mg II equivalent width, however, is reported in at least one previous study. Although the significance is not very strong (86 percent), there is a possible negative relationship between inclination angle and Fe II strength which, if true, could explain the Fe II anti-correlation with [O III ] strength associated with Eigenvector 1. Interestingly, there are objects having almost edge-on inclinations while still exhibiting broad lines. This could be explained by a torus which is either clumpy (allowing sight lines to the central engine) or mis-aligned with the accretion disk.
arXiv commentProceedings from the conference 'Quasars at all cosmic epochs' held in Padova, Italy (2-7 April 2017)
References in corpus (13)
- First Year Wilkinson Microwave Anisotropy Probe (WMAP) Observations: Determination of Cosmological Parameters
- Unified Schemes for Radio-Loud Active Galactic Nuclei
- The Sixth Data Release of the Sloan Digital Sky Survey
- Revisiting the Unified Model of Active Galactic Nuclei
- The diversity of quasars unified by accretion and orientation
- Fe II Emission in 14 Low-Redshift Quasars: I - Observations
- [O III] Equivalent Width and Orientation Effects in Quasars
- Double Lobed Radio Quasars from the Sloan Digital Sky Survey
- On the jet speeds of classical double radio sources
- Correlations of Quasar Optical Spectra with Radio Morphology
- Orientation effects on spectral emission features of quasars
- The orientation dependence of quasar single-epoch black hole mass scaling relationships
- Optical and radio properties of giant radio quasars: Central black hole characteristics