We propose XMM-Newton observations of four local AGN which have recently beenobserved to transition between types 1 and 2 (or vice versa). Our targets wereidentified in a thorough search of the BASS sample of BAT-selected AGN, and havemulti-epoch optical spectra covering the past 10-20 years. Each source has anarchival X-ray spectrum from either XMM-Newton, Chandra or SWIFT, allowing us tocompare their current X-ray spectral properties with those observed before theoptical state transition. The proposed observations will provide a unique andtimely insight into accretion disc physics, inform our understanding of when andhow the Broad Emission Line Region is formed around AGN, and provide a valuablebenchmark in studies of changing-state AGN.
Instrument
EMOS1, EMOS2, EPN, OM, RGS1, RGS2
Temporal Coverage
2022-07-27T14:06:41Z/2022-12-03T11:34:15Z
Version
20.09_20221024_1724
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 Matthew Temple, 2023, 'Quantifying X-Ray Spectral Variability in a New Sample of Changing-State AGN', 20.09_20221024_1724, European Space Agency, https://doi.org/10.57780/esa-uj4ga5t
