|Title||The Nature of Soft X-Ray Weak Quasars|
|Author||Dr Norbert Schartel|
|Description||About 10% of the quasars are soft X-ray-weak: its X-ray emission is by a factor 10-30 fainter than in typical quasars. Different observational parameters suggest that absorption is the primary cause of their X-ray weakness, but a uniform absorbing screen cannot explain the X-ray and ultraviolet emission. Our previous XMM-Newton observations of three quasars confirm that their weakness is related to absorption. However, our data show an absorbing column density and ionization parameter, which are much higher than detected for other AGNs. We propose to observe the last two outstanding X-ray weak quasars of the complete sample of Brand, Laor and Wills et al. (2000), which will allow to rigorously study the X-ray absorption scenario in X-ray weak quasars.|
|Publication||No observations found associated with the current proposal|
|Instrument||EMOS1, EMOS2, EPN, OM, RGS1, RGS2|
|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.
|Publisher And Registrant||European Space Agency|
|Credit Guidelines||European Space Agency, 2006-07-13T00:00:00Z, 030089, 17.56_20190403_1200. https://doi.org/10.5270/esa-u8qj3rp|