|Title||NGC 925 ULX-3: a key to understanding extreme ULX variability|
|Author||Dr Hannah Earnshaw|
|Description||We propose a broadband observation of the transient ULX, NGC 925 ULX-3, for 40ks with XMM-Newton quasi-simultaneous with a 100ks observation with NuSTAR. This source exhibits extreme levels of long-term variability of over a factor of 36, a feature also seen in several ULXs identified as neutron stars to date and linked to different possible mechanisms that are not well understood. We plan to trigger this observation when the source exceeds a flux of 6x10^−13 ergs-s-cm2, determined from an existing Swift monitoring campaign, allowing us to constrain its high-flux broadband spectrum. Coupled with this monitoring and a complementary proposal at a low flux, we will be able to build an understanding of the geometry and physical processes in play in this extreme accreting system.|
|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, 2021-11-24T00:00:00Z, 086276, 18.02_20200221_1200. https://doi.org/10.5270/esa-[xxxxxxx]|