The mounting evidence for non-matching AGN spectral type and X-ray absorption isalmost invariably based on non-simultaneous optical and X-ray observations. Bothproperties are known to be variable in some AGN. The aim of the present proposalis to solve the dichotomy on whether both optical and X-ray obscuration areclosely related (as predicted by the unified AGN picture) but variable, or elsethese properties are really mismatched in some objects. We propose XMM-Newtonobservations, simultaneous to optical spectroscopy, of a representativeselection of AGNs whose optical spectral type is known to be variable.
Instrument
EMOS1, EMOS2, EPN, OM, RGS1, RGS2
Temporal Coverage
2004-01-23T16:53:53Z/2005-01-15T21:35:45Z
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.
European Space Agency, Prof XAVIER BARCONS, 2006, 'THE X-RAY/OPTICAL AGN TYPE MISMATCH: REALITY OR VARIABILITY', 17.56_20190403_1200, European Space Agency, https://doi.org/10.5270/esa-fctyz6c
