|Title||Understanding state transitions in ULXs: wind spectroscopy of ULX bright states|
|Author||Dr Ciro Pinto|
|Description||In recent work done with XMM-Newton, we have discovered that ultraluminous X-ray sources (ULXs) have powerful winds in agreement with theoretical predictions of super-Eddington accretion. Such winds vary on short timescales and can temporarily block and reprocess the disc X-ray photons, thus changing the spectral shape of the source. Enhanced X-ray variability is seen during ULX highest states including flux dips in soft ULXs and flares in hard ones, possibly due to a variable wind in our line of sight. We propose to test this, by studying the hard NGC 4559 X-7 and the soft NGC 55 ULX-1. 130ks XMM-Newton observation per object triggered during a high state will enable us to perform time--flux-resolved X-ray spectroscopy and probe the transition between soft, intermediate, and hard states.|
|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, 2023-01-04T00:00:00Z, 088396, 19.16_20210326_1200. https://doi.org/10.57780/esa-phk6akn|