Emission Lines and a Quasar's Spectral Energy Distribution

Previous abstract Next abstract

Session 18 -- AGN Spectroscopy
Display presentation, Monday, 9, 1995, 9:20am - 6:30pm

[18.09] Emission Lines and a Quasar's Spectral Energy Distribution

Belinda Wilkes, Smita Mathur, Jonathan McDowell, Martin Elvis (SAO)

Quasar spectral energy distributions (SEDs) vary significantly from object to object (Elvis et.al. 1994). In particular the relative strengths of the blue bump, the soft X-ray excess, the harder X-ray emission and the wavelength of the far-infrared cut-off all cover a wide range. If the broad emission lines do, as is generally believed, arise in gas which is photoionised by a quasar's SED, we expect the relative strengths of the emission lines to be intimately related to that SED.

We use the far-infrared (IR) through soft X-ray (100 \micron -- 3.5 keV) SEDs of our sample of 43 quasars observed with high-signal-to-noise in the X-rays (Elvis et.al. 1994), combined with low-resolution, optical spectrophotometry obtained within a few months of the optical/IR continuum measurements to investigate SED/emission line relations. Preliminary results show that the optical lines MgII and the Balmer series are strongly related to the X-ray luminosity. We find no relation between the emission lines and the blue bump strength, no optical Baldwin effect and no relation between FeII emission and the X-ray spectral slope. This latter contrasts with earlier resluts.

Elvis et.al. 1994 ApJS in press (November)

Monday program listing