We have found a population of hard spectrum X-ray AGN which have broadlines. These may be bright examples of the hard sources that dominate the sourcecounts in the 2-10virgulkeV band, and therefore produce most of the X-ray emission inthe Universe. These sources are an exciting and surprising discovery because thehard X-ray AGN were expected to have narrow lines. We propose to observe asample of these AGN with XMM to find out why their X-ray emission is hard. EPICspectra will enable us to distinguish between absorption of an otherwisestandard soft spectral shape, and intrinsically hard emission, perhaps producedby advection dominated accretion. If they are not absorbed, popular models forthe origin of the X-ray background will need to be rewritten.
Instrument
EMOS1, EMOS2, EPN, OM, RGS1, RGS2
Temporal Coverage
2001-01-03T09:52:13Z/2002-04-11T17:43:28Z
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, Dr Francisco J. Carrera, 2003, 'Investigating the origin of hard X-ray spectra in broad-line AGN', 17.56_20190403_1200, European Space Agency, https://doi.org/10.5270/esa-ycahljd
