The broad C IV emission lines in weak line quasars (WLQs) are significantlyweaker than expected from the anti-correlation between C IV equivalent width andthe Hbeta-based Eddington ratio. This discrepancy may be reconciled if theEddington ratios of WLQs are higher than those indicated by Hbeta. We aim totest this hypothesis by measuring the hard-X-ray photon index in all WLQs withHbeta measurements thus obtaining robust determinations of their accretionrates. Steep spectral slopes will indicate that high accretion rates areresponsible for the line weakness in WLQs. Otherwise, additional parameters maycontrol broad emission line equivalent widths. The results will yield crucialinsights about the accretion process and broad emission line formation in all active galactic nuclei.
Instrument
EMOS1, EMOS2, EPN, OM, RGS1, RGS2
Temporal Coverage
2016-07-19T01:11:35Z/2017-01-04T18:30:53Z
Version
17.56_20190403_1200
Mission Description
The European Space Agencys (ESA) X-ray Multi-Mirror Mission (XMM-Newton) was launched by an Ariane 504 on December 10th 1999. XMM-Newton is ESAs second cornerstone of the Horizon 2000 Science Programme. It carries 3 high throughput X-ray telescopes with an unprecedented effective area, and an optical monitor, the first flown on a X-ray observatory. The large collecting area and ability to make long uninterrupted exposures provide highly sensitive observations. Since Earths atmosphere blocks out all X-rays, only a telescope in space can detect and study celestial X-ray sources. The XMM-Newton mission is helping scientists to solve a number of cosmic mysteries, ranging from the enigmatic black holes to the origins of the Universe itself. Observing time on XMM-Newton is being made available to the scientific community, applying for observational periods on a competitive basis.
European Space Agency, Prof Ohad Shemmer, 2018, 'Weak Line Quasars at High Redshift: Extremely High Accretion Rate SourcesquestionMark', 17.56_20190403_1200, European Space Agency, https://doi.org/10.5270/esa-u3q2hrl
