A dataset provided by the European Space Agency

Name: Weak Line Quasars at High Redshift: Extremely High Accretion Rate Sources?
Published: 2018-01-24T23:00:00Z

Proposal ID	078236
Title	Weak Line Quasars at High Redshift: Extremely High Accretion Rate Sources?
Download Data Associated to the proposal	https://nxsa.esac.esa.int/nxsa-sl/servlet/data-action-aio?obsno=0782360101 https://nxsa.esac.esa.int/nxsa-sl/servlet/data-action-aio?obsno=0782360201
DOI	https://doi.org/10.5270/esa-u3q2hrl
Principal Investigator, PI	Prof Ohad Shemmer
Abstract	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.
Publications	Steep Hard-X-Ray Spectra Indicate Extremely High Accretion Rates in Weak Emission-line Quasars \|Marlar Andrea Shemmer Ohad et al. \| ApJ \| 865-92 \| 2018 \| 2018ApJ...865...92M \| http://ui.adsabs.harvard.edu/#abs/2018ApJ...865...92M Classification of 4XMM-DR9 sources by machine learning \|Zhang Yanxia Zhao Yongheng \| MNRAS \| 503-5263 \| 2021 \| 2021MNRAS.503.5263Z \| http://ui.adsabs.harvard.edu/#abs/2021MNRAS.503.5263Z Xu2011HESS: A large sample of highly accreting serendipitous AGN under the XMMu2011Newton microscope \|Laurenti M. Tombesi F. et al. \| AN \| 344-20230053 \| 2023 \| 2023AN....34430053L \| http://ui.adsabs.harvard.edu/#abs/2023AN....34430053L The XMM-Newton Line Emission Analysis Program (X-LEAP). I. Emission-line Survey of O VII O VIII and Fe L-shell Transitions \|Pan Zeyang Qu Zhijie et al. \| ApJS \| 271-62 \| 2024 \| 2024ApJS..271...62P \| http://ui.adsabs.harvard.edu/#abs/2024ApJS..271...62P From Active Stars to Black Holes: A Discovery Tool for Galactic X-Ray Sources \|Rodriguez Antonio C. \| PASP \| 136-054201 \| 2024 \| 2024PASP..136e4201R \| http://ui.adsabs.harvard.edu/#abs/2024PASP..136e4201R Robust constraints on feebly interacting particles using XMM-Newton \|Luque Pedro De la Torre Balaji Shyam \| PhRvD \| 109-L101305 \| 2024 \| 2024PhRvD.109j1305L \| http://ui.adsabs.harvard.edu/#abs/2024PhRvD.109j1305L Multimessenger search for electrophilic feebly interacting particles from supernovae \|Luque Pedro De la Torre Balaji Shyam \| PhRvD \| 109-103028 \| 2024 \| 2024PhRvD.109j3028L \| http://ui.adsabs.harvard.edu/#abs/2024PhRvD.109j3028L Importance of Cosmic-Ray Propagation on Sub-GeV Dark Matter Constraints \|De la Torre Luque Pedro Balaji Shyam \| ApJ \| 968-46 \| 2024 \| 2024ApJ...968...46D \| http://ui.adsabs.harvard.edu/#abs/2024ApJ...968...46D
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.
Creator Contact	https://www.cosmos.esa.int/web/xmm-newton/xmm-newton-helpdesk
Date Published	2018-01-24T23:00:00Z
Last Update	2025-01-27
Keywords	"accretion process", "weak line quasars", "iv equivalent width", "line weakness", "robust determinations", "eddington ratio", "accretion rates", "additional parameters", "hbeta measurements", "anti correlation", "iv emission lines", "eddington ratios", "spectral slopes", "active galactic nuclei"
Publisher And Registrant	European Space Agency
Credit Guidelines	European Space Agency, Prof Ohad Shemmer, 2018, 'Weak Line Quasars at High Redshift: Extremely High Accretion Rate Sources?', 17.56_20190403_1200, European Space Agency, https://doi.org/10.5270/esa-u3q2hrl