|Title||Are there X-ray quiet quasars|
|Author||Dr Bernd Aschenbach|
|Description||GT-The X-ray-to-optical energy distribution of quasars, alpha_ox, is required to relate the quasar statistics, evolution and luminosity function in the two wavebands and to understand its. broad band emission. In a recent study of radio-quiet quasars from ROSAT observations there is a small number of objects showing very weak X-ray emission compared to their optical luminosity. The nature of these X-ray quiet quasars is unknown and it is not clear whether they are the X-ray quiet extremes of a continous distribution or a distinct class of objects. XMM observations seem to be the only way to understand this new population of quasars and to distinguish different explanations for the unknown physical nature of these objects.|
|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, 2003-08-09T00:00:00Z, 010366, 17.56_20190403_1200. https://doi.org/10.5270/esa-7ab43zm|