| Proposal ID | 015061 |
| Title | The Nature of Soft X-Ray Weak Quasars |
| Download Data Associated to the proposal | https://nxsa.esac.esa.int/nxsa-sl/servlet/data-action-aio?obsno=0150610101 |
| DOI | https://doi.org/10.5270/esa-zsf5xnr |
| Principal Investigator, PI | Dr Norbert Schartel |
| Abstract | About 1/10 of the quasars can be classified as soft X-ray-weak, whose X-rayemission is by a factor 10-30 fainter than in typical quasars. They show astrong correlation between alpha OX and the C IV absorption equivalentwidth, which suggest that absorption is the primary cause of their soft X-ray-weakness. But the shape of the correlation can not be reproduced by an uniformscreen covering both the X-ray source and the ultraviolet emission. Thereforeeither the UV and X-ray absorbers are not identical (warm absorber, partly covered, only scattered flux) or the X-ray weakness is due to a peculiarproperty of the nuclear emission, as extreme variability or unusual steepness. |
| Publications |
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| Instrument | EMOS1, EMOS2, EPN, OM, RGS1, RGS2 |
| Temporal Coverage | 2002-11-03T01:06:03Z/2003-05-14T19:52:57Z |
| 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 | 2004-06-04T00:00:00Z |
| Last Update | 2025-01-27 |
| Keywords | "soft xray weakness", "identical warm absorber", "ultraviolet emission", "xray absorbers", "alpha ox", "xray source", "uniform screen", "nuclear emission", "xray weakness", "xray emission", "scattered flux", "typical quasars", "partly covered", "soft xray weak" |
| Publisher And Registrant | European Space Agency |
| Credit Guidelines | European Space Agency, Dr Norbert Schartel, 2004, 'The Nature of Soft X-Ray Weak Quasars', 17.56_20190403_1200, European Space Agency, https://doi.org/10.5270/esa-zsf5xnr |