The physical process responsible for the so-called optical changing-look AGN,i.e. sources in which the broad lines produced by material surrounding the SMBHappear or disappear, is still very debated. We recently caught one of these rareobjects in the act of developing broad lines. This is the first time a source isobserved during the changing-look phase. The XMM-Newton/NuSTAR DDT we triggeredhas shown an extremely peculiar super-soft X-ray spectrum, with only a fewphotons above 2 keV. We propose here two 42 ks XMM-Newton observations of thisunique source to monitor its spectral behaviour, and in particular thereappearance of the hard component. We will also study its outflow and possiblydetect a K line.
Instrument
EMOS1, EMOS2, EPN, OM, RGS1, RGS2
Temporal Coverage
2019-05-06T21:56:01Z/2019-11-03T00:16:12Z
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 Claudio Ricci, 2020, '1ES 1927+654\: the first optically-identified changing-look', 17.56_20190403_1200, European Space Agency, https://doi.org/10.5270/esa-bsaac9m
