| Proposal ID | 069251 |
| 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=0692510101 |
| DOI | https://doi.org/10.5270/esa-2vdpxi9 |
| Principal Investigator, PI | Prof Ohad Shemmer |
| Abstract | The Sloan Digital Sky Survey has recently discovered a remarkable group of ~80quasars at z=2.2-5.9 with extremely weak emission lines in their rest-frame UVspectra. We propose to extend our XMM-Newton observations of such sources andobtain imaging spectroscopy of four quasars of this class with a total exposuretime of 165 ks, providing ~1000 photons per source. This will enable an accuratemeasurement of the hard-X-ray photon index required for a robust determinationof the accretion rate in each source. Steep spectral slopes will indicate thathigh accretion rates may be responsible for the intrinsic weakness of the UVemission lines. The proposed observations will lead to new insights about theaccretion process and broad emission line formation in all active galactic nuclei. |
| Publications |
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| Instrument | EMOS1, EMOS2, EPN, OM, RGS1, RGS2 |
| Temporal Coverage | 2012-06-22T21:35:30Z/2012-10-24T16:35:29Z |
| 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 | 2013-11-16T00:00:00Z |
| Last Update | 2025-01-27 |
| Keywords | "weak emission lines", "accretion rate", "accretion process", "weak line quasars", "xmm newton", "uv emission lines", "XMM-Newton", "total exposure time", "accretion rates", "accretion rate sources", "XMM", "imaging spectroscopy", "spectral slopes", "active galactic nuclei" |
| Publisher And Registrant | European Space Agency |
| Credit Guidelines | European Space Agency, Prof Ohad Shemmer, 2013, 'Weak Line Quasars at High Redshift: Extremely High Accretion Rate Sources', 17.56_20190403_1200, European Space Agency, https://doi.org/10.5270/esa-2vdpxi9 |