| Name | 040661 |
| Title | X-ray weak broad-line quasars: absorption or intrinsic X-ray weakness |
| URL | https://nxsa.esac.esa.int/nxsa-sl/servlet/data-action-aio?obsno=0406610101 |
| DOI | https://doi.org/10.5270/esa-53v0hg6 |
| Author | Dr Guido Risaliti |
| Description | We propose seven short observations of X-ray weak quasars, with the aim of understanding the origin of their low X-ray to optical ratio. The sources belong to the spectroscopically selected Hamburg Quasar Survey, and have been observed with Chandra and in the optical. They show unusual optical properties (most of them have a red continuum and very high EW broad emission lines), while the nature of their X-ray weakness (intrinsic or due to absorption ?) is not yet clear, because of the low signal-to-noise of the Chandra spectra. Four short observations with XMM-Newton gave the answer for four sources, showing absorption in two cases, and an unabsorbed spectrum in the other two. This shows that XMM-Newton can unveil the nature of the X-ray emission of these sources. |
| Publication | No observations found associated with the current proposal |
| Instrument | EMOS1, EMOS2, EPN, OM, RGS1, RGS2 |
| Temporal Coverage | 2006-06-01T16:44:59Z/2007-05-04T11:03:23Z |
| Version | 17.56_20190403_1200 |
| Mission Description | The European Space Agency's (ESA) X-ray Multi-Mirror Mission (XMM-Newton) was launched by an Ariane 504 on December 10th 1999. XMM-Newton is ESA's 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 Earth's 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 | 2008-05-31T00:00:00Z |
| Publisher And Registrant | European Space Agency |
| Credit Guidelines | European Space Agency, Dr Guido Risaliti, 2008, 040661, 17.56_20190403_1200, European Space Agency, https://doi.org/10.5270/esa-53v0hg6 |