A dataset provided by the European Space Agency

Name: Unifying X-ray Weak Quasars: Is there a Highly Absorbed Component in PHL 1811?
Published: 2016-12-12T23:00:00Z

Proposal ID	076191
Title	Unifying X-ray Weak Quasars: Is there a Highly Absorbed Component in PHL 1811?
Download Data Associated to the proposal	https://nxsa.esac.esa.int/nxsa-sl/servlet/data-action-aio?obsno=0761910201
DOI	https://doi.org/10.5270/esa-lggb7q6
Principal Investigator, PI	Prof Karen Leighly
Abstract	Quasars exhibit X-ray emission proportional to their UV emission, and most X-rayweak objects are absorbed. The exception may be PHL 1811, a nearby quasar thatis 25--100 times X-ray fainter than expected, but has a steep and variable X-rayspectrum suggesting a direct view of the central engine. It also has unusual UVemission line properties that are consistent with its X-ray weak SED. Searchesfor PHL 1811 analogs, chosen by their UV spectral properties, find objects thatare X-ray weak but which have hard X-ray spectra, suggesting absorption.Previous X-ray observations of PHL 1811 extended only to 6 keV, so a highlyabsorbed component cant be ruled out. We propose coordinated XMM- Newton andNuSTAR observations to see whether PHL 1811 is intrinsically normal and highly absorbed.
Publications	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 NuSTAR Observations of Intrinsically X-Ray Weak Quasar Candidates: An Obscuration-only Scenario \|Wang Chaojun Luo B. et al. \| ApJ \| 936-95 \| 2022 \| 2022ApJ...936...95W \| http://ui.adsabs.harvard.edu/#abs/2022ApJ...936...95W 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	2015-11-29T09:38:07Z/2015-11-30T02:08:07Z
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	2016-12-12T23:00:00Z
Last Update	2025-01-27
Keywords	"uv spectral properties", "xray weak sed", "hard xray spectra", "phl 1811 analogs", "nearby quasar", "xray weak objects", "phl 1811", "uv emission", "central engine", "NuSTAR", "coordinated xmm newton", "phl 1811 ?.", "XMM", "xray weak", "variable xray spectrum", "xray fainter", "absorbed component"
Publisher And Registrant	European Space Agency
Credit Guidelines	European Space Agency, Prof Karen Leighly, 2016, 'Unifying X-ray Weak Quasars: Is there a Highly Absorbed Component in PHL 1811?', 17.56_20190403_1200, European Space Agency, https://doi.org/10.5270/esa-lggb7q6